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This study presents a multi-objective optimization method for a tractor driveline based on the diversity maintenance strategy of gradient crowding. The objective was to address the trade-off between high power and low fuel consumption rates in a tractor driveline by optimizing the distribution of driveline ratios, aiming to enhance overall driving performance and reduce fuel consumption. This method introduces a strategy for evaluating gradient crowding to reduce non-inferior solution sets during selection to ensure the uniform and wide distribution of solutions while maintaining population diversity. The transmission ratio of a tractor is optimized by varying the input of the transmission ratios in each gear, constraining the theoretical tractor driving rate, common transmission ratio, and drive adhesion limit, and introducing the diversity maintenance strategy of gradient crowding. The goal is to reduce the loss rate of driving power and specific fuel consumption as much as possible. The analysis results demonstrate that the GC_NSGA-II algorithm, incorporating the evaluation strategy of gradient crowding, achieves greater diversity and a more uniform distribution in the front end. After verifying the algorithm, the optimized tractor showed a reduction of 41.62 (±S.D. 0.44)% in the theoretical loss rate of driving power and 62.8 (±S.D. 0.56)% in the loss rate of specific fuel consumption, indicating that the tractor’s drive performance significantly improved, accompanied by a substantial reduction in the fuel consumption rate. These findings affirm the feasibility of the proposed optimization method and provide valuable research insights for enhancing the overall performance of tractors.

This paper describes the simulative approach to calibrate an already extremely highly turbocharged industrial diesel engine for higher low-speed torque. The engine, which is already operating at its cylinder-pressure maximum, is to achieve close to 30 bar effective mean pressure through suitable calibration between the compression ratio, piston-bowl shape and injection strategy. The basic idea of the study is to lower the compression ratio for even higher injection masses and boost pressures, with the resulting disadvantages in the area of emissions and fuel consumption being partially compensated for by optimizations in the areas of piston shape and injection strategy. The simulations primarily involve the use of the 3D CFD software Converge CFD for in-cylinder calibration and a fully predictive 1D full-engine model in GT Suite. The simulations are based on a two-stage turbocharged 1950 cc four-cylinder industrial diesel engine, which is used for validation of the initial simulation. With the maximum increase in fuel mass and boost pressure, the effective mean pressure could be increased up to 28 bar, while specific consumption increased only slightly. Depending on the geometry, NOx or CO and UHC emissions could be reduced. [ABSTRACT FROM AUTHOR]

Various physicomechanical and fuel properties of sawdust briquettes with Abelmoschus esculentus(okra)waste binder additive were determined. Elemental analysis was done to determine the Oxygen(O), hydrogen (H), and Carbon content of the briquettes. Volatile matter, ash content, fixed carbon, heating value, density, compressive strength, stability, durability, and shatter resistance. The 5%, 10%, 15%, and 20% Abelmoschus esculentus composition per weight were used. The 5% Okra briquette had the highest volatile matter and heating value of 85.46% and 17,820 kJ kg-1, while maintaining the lowest ash content and moisture content of 1.59% and 7.6%, respectively. The briquette with 5% Abelmoschus esculentus (Okra) composition had the highest Carbon (C), Hydrogen(H), and Oxygen (O) contents of 42.70%, 5.64%, and 42.76%, respectively. The results were within international standard limits for briquettes. Based on the results obtained, the sawdust-Abelmoschus esculentusbriquette can adequately replace firewood in sub-Saharan Africa. Okra showed great potential as a binder with a very high hardness level of 7 hours in the water without disintegration. Increased utilization of agro-wastes briquettes will ensue while carbon emissions from the open burning of wastes will reduce. Equally, the use of clean cookstoves will increase with the production of these briquettes and will lead to a reduction in the present rate of deforestation that will result from domestic heating processes. [ABSTRACT FROM AUTHOR]

In this paper, an effort has been made to produce biodiesel from Neem oil (Azadirachta Indica) and to perform a comparative analysis on various blends with diethyl ether (DEE) and alumina nanomaterials at different volume fractions. The fraction of alumina oxide (Al2O3) nanomaterials with the blend (Pure Diesel 40% + Neem BD 40% + Ethanol) is varied in the range of 25, and 50 ppm. Experimental outcomes displayed that the physical and chemical properties of the biodiesel enhanced with the dispersion of alumina nanomaterials. The performance characteristics of the biodiesel blend such as brake thermal efficiency were increased up to 7.2% and brake specific fuel consumption was reduced up to 6.7% by adding the adding nanomaterial at 25 ppm of alumina nanomaterials compared with the pure diesel fuel. This is because of the higher surface area of the nanomaterial, which acts as the positive catalyst and increases the reaction rate. The Al2O3 positively altered the critical parameters like the ignition temperature and the ignition delay of a DE. Moreover, the addition of alumina nanomaterials gave better emission characteristics on the account of reduction in the HC, CO, and smoke emissions at higher loads compared to NDB. Al2O3 enhances the performance and the anti-knocking ability of the fuel. At 100% load conditions, the nitrogen oxide (NOx) emissions of NBD2 (Diesel 40% + Neem BD 40% + Ethanol 20% (90% volume + DEE 10%) are lower than NBD by 17.5%.

Gas turbine fuel burn for an aircraft engine can be obtained analytically using thermodynamic cycle analysis. For large-diameter ultra-high bypass ratio turbofans, the impact of nacelle drag and propulsion system integration must be accounted for in order to obtain realistic estimates of the installed specific fuel consumption. However, simplified models cannot fully represent the complexity of installation effects. In this paper, we present a method that combines thermodynamic cycle analysis with detailed Computational Fluid Dynamics (CFD) modelling of the installation aerodynamics to obtain the fuel consumption at a given mission point. The flow field and propulsive forces arising in a transport aircraft powered by an ultra-high bypass ratio turbofan at cruise are first examined to characterise the operating conditions and measure the sensitivity to variations of the incidence at transonic flight. The proposed methodology, in which dynamic balance of the vehicle is achieved at each integration point, is then applied along a cruise segment to calculate the cumulative fuel burn and the change in the specific fuel consumption.

The energy crisis and depleting fossil fuel resources have always been the focus of researchers. Fuel consumption of agricultural tractors is not an exception. Researchers have used different methods to predict fuel consumption. With the development of artificial intelligence in the last decade, all re-searchers’ attention has been directed towards it. Deep learning is a subset of machine learning, which was inspired by the data processing patterns in the human brain. The deep learning method has been used in research due to the advantages of high accuracy and generalization. So far, no research has used this method to predict fuel consumption. In this research, field experiments were carried out in sandy clay loam and clay soils to model the temporal fuel consumption and specific fuel consumption of an agricultural tractor using a convolutional neural network (CNN), while having some parameters such as the soil type, soil conditions, tool parameters, and operation pa-rameters. The experiments were conducted within each soil texture in a factorial manner based on the randomized complete block design (RCBD) with three replicates. For each soil texture, various moisture levels (8–17% for dry and 18–40% for moist soils), tractor forward speeds (1.2, 1.6, 1.8, and 2.2 km h−1), working depths (30 and 50 cm), the number of passes (2 and 6), and tire inflation pressure (20 and 25 psi) were selected, and cone index, dynamic load, and moisture content were measured in each experimental section. The designed networks used to predict the instant fuel consumption were of a CNN type. The results indicated that the network developed based on the Sgdm algorithm outperformed the others, and thus it was selected for modeling purposes. The network was evaluated based on R2 and MSE criteria. For the temporal fuel consumption, the best results were obtained while using 8-510-510-1 architecture with R2 = 0.9729 and MSE = 0.0049. The 8-100-95-1 architecture also led to the best prediction of the specific fuel consumption with R2 of 0.9737 and MSE of 0.0054. The high prediction accuracy and low error in this research compared to previous studies indicate the superiority of this method in order to predict fuel consumption. It was also observed from the results that the input parameters, which include soil, tool, and operational parameters, are all effective on fuel consumption. Proper management of some parameters, such as working depth, tire inflation pressure, and forward speed, can help to optimize fuel consumption.

In recent decades, works have been published on the Hybrid Renewable Energy System (HRES) to provide available, feasible, and efficient renewable energy systems. Several studies have looked at the efficiency of the systems in terms of sustainability through performance parameters. This study aims at estimating the optimum HRES based on biomass and photovoltaic (PV) using the case study of 94 residential buildings with an electricity demand of 84.5 kWp. The influence of key parameters (global solar irradiation, component efficiencies, fuel consumption, economic convenience) and their impact on the performance and cost of the system is investigated. The optimum system is evaluated by the simulation software HOMER Pro. A single year of hourly data is used to analyze the component performance and the overall system performance. In this work, a mathematical model based on the IEC 61724 standard is used to incorporate numerous performance indicators that are critical for estimating the performance of a hybrid system. Evaluating results comprise of three performance basic indicators, namely, energy efficiency, system sizing, and economic parameters. [ABSTRACT FROM AUTHOR]

The rapid increase of diesel engines and diminishing of diesel fuel creates a challenge for researchers to find alternative fuel. The present experiment is performed on a 3.5 kW diesel engine. Here, diesel is replaced with pure lemongrass oil (LGO) of10%, 20%, and 30% by volume with diesel. The obtained data from the experimental work may exhibit the Brake Thermal Efficiency (BTE) of LG20 equivalent to pure diesel. The specific fuel consumption (SFC) of LGO blends shows an increase compared to diesel, due to the lower heating value for LGO blends. On the other hand, LGO blends show lower emissions of NOX, due to the lower peak flame temperature. When compared to the other samples, the LG30 gives a maximum reduction in NOX emissions; of 10.33%. When compared to biodiesel blends, diesel fuel shows a significant increase in the Net Heat Release rate (NHR).

Numerous studies on using light fuels in compression ignition engines to reduce emission and increase efficiency have been done. The Reactivity Controlled Compression Ignition engines are one of these studies. Nevertheless, using heavy fuels vapor for achieving partially premixed combustion is not investigated. Using diesel fume (to upgrade conventional combustion to premixed combustion) resolves the need for a secondary fuel tank in a car. However, diesel fuel has heavy hydrocarbons and is a high reactivity fuel. So in this study, diesel has evaporated in a tank, and its vapor has injected into the intake air for studying a semi homogeneous combustion. The tests have performed at 2000 rpm (the speed of maximum torque). According to the achieved results, although diesel has heavy hydrocarbons and is a high reactivity fuel, adding diesel fumigation can reduce soot and NOx emissions up to 20% and 50%, respectively. Increasing load reduces the positive impact of adding diesel fumigation on soot and NOx emission reduction. However, the positive impact of adding diesel fumigation continues up to 80% of the full load. Adding diesel fumigation has no impact on cyclic variation and ringing intensity, but increases CO and HC emission. The evaporation of diesel averagely consumes 15% of brake power. Also on average, 5% of diesel evaporation energy can be supplied by recovering heat energy from the exhaust gas (warming up diesel from ambient temperature to the exhaust gas temperature). [ABSTRACT FROM AUTHOR]

This work proposes to model a small series hydraulic hybrid vehicle (SHHV) for the power demand of a real driving cycle. The real driving cycle was measured with a low-cost Bluetooth Scanner connected to the On-Board Diagnostic (OBD) port of the vehicle and applied to a computational model. The hydraulic power to drive the modeled SHHV was supplied by a hydraulic pump and/or by an accumulator. Optimization tools were used to size the hydraulic components. Furthermore, the optimization tools were also used to calculate the values of the control variables for activating the pump, accumulator and the hydraulic motor, in order to have the minimum fuel consumption by the vehicle's combustion engine. The model implemented had its fuel consumption reduced by 37% in relation to the passenger car utilized for the driving cycle data acquisition. [ABSTRACT FROM AUTHOR]

Air pollution from ships is increasing due to higher global demand of goods, and with them, global emission standards as well. These standards are prescribed by MARPOL Annex VI and the introduction of emission control areas (ECA). Ships built before 1990. do not have to comply with these rules, but ships built after the early 2000. must follow "NOx Emission Tier I", which allows 17g/kWh NOx (for the slow speed diesel engines with <130 rpm), and selective catalytic reactors (SCR) are not necessary. Tier III NOx Emission standard was enforced in 2016 and it requires an 80% reduction in NOx emission compared to the Tier I, specifically 3.4 g/kWh, which can not be achieved without SCR or without using some other types of fuels. The focus of this paper is to do analysis how the ammonia dosage to SCR affects to the NOx formation in exhaust gasses on various engine speed (loads), as well as how it affects to some important engine parameters and specific fuel oil consumption (SFOC). The analysis was performed on Kongsberg engine room simulator (ERS), MC 90-V Model, as well as on MATLAB by using mathematical models. All external influences are excluded from the analysis like wind or rough sea. All data on different scenarios has been recorded after prolonged period to avoid inconsistencies. The results are shown graphically, and conclusions are presented. [ABSTRACT FROM AUTHOR]

A 9.69 kW power tiller's drawbar performance was tested by using a drawbar loading vehicle consisting of a power tiller with a mould board (MB) plough. A spring-loaded dynamometer was attached between the tested power tiller and the loading vehicle to measure the drawbar pull. The drawbar pull was changed from 0.905 kN to 2.232 kN by varying the operating depth of the MB plough. Empirical equations were developed to correlate the drawbar pull to the wheel slip, drawbar power, fuel consumption, and drawbar specific fuel consumption (DBSFC), and one was developed to correlate the drawbar power to the wheel slip. The wheel slip increased exponentially with an increase in the drawbar pull and drawbar power. A maximum wheel slippage of 48.94% was observed at a 2.232 kN drawbar pull and 0.763 kW drawbar power. A second-degree polynomial equation was found to correlate the drawbar pull to the drawbar power, fuel consumption, and DBSFC. The maximum drawbar power was found as 0.763 kW at a 2.02 kN drawbar pull, which was 7.87% of the rated engine power. The fuel consumption increased by 66.93%, and the DBSFC reduced by 10.56% due to the increase of the drawbar pull from 0.905 kN to 2.232 kN. The lowest DBSFC of 2.01 kg·kWh-1 was found at a 2.232 kN drawbar pull. [ABSTRACT FROM AUTHOR]

Introduction. The study presents the results of the calculation of greenhouse gas emissions and polluting solids by vehicles fleet on the basis of three independent estimates of the set of initial data on the breakdown of the fleet by technological classes (the number and types of vehicles of different ecological classes, annual mileage, etc.). Such data is not provided in the forms of state statistical reports and is generated by the researchers. The article solves the problem of determining their significance for calculating the total emissions in the context of a large data array for the territory of Russia.Materials and methods. Three different versions to the calculation of greenhouse gas emissions (basic version, equalization of transport work and new approach - equalization of fuel consumption) are proposed in order to identify differences in the obtained emissions in different conditions (i.e., to determine quantitative characteristics of the accuracy of the final values). A new method has been developed for assessing the effect of average mileage and vehicle distribution on classes on the total emissions values, implemented within each proposed version. In addition, two types of sensitivity formulas are formed by the authors to assess the impact of vehicle distribution on classes and average mileage to final emission calculations. The use of these formulas provides scientific analysis and interpretation of the influence of the factors in expert review on the final values of the emissions of each type.Results. The differences in sorting cars into classes in expert evaluations were revealed and the closest ones are determined. It was found that the most sensitive to changes in mileage and class of cars, on which fuel consumption depends, are CO2 emissions.Conclusion. The scientific sensitivity analysis of both types showed the importance of maintaining the principles underlying expert evaluation from year to year in order to ensure that the results obtained are consistent.

Relevance. Redeveloping of the existing heat-power equipments is one of the priority areas of power generation development. Adoption of gas turbine unit to the thermal scheme of steam-power energy unit with the preservation of power plant infrastructure is a less costly variant comparing with the construction of new combined cycle power plants energy units. One of the low-cost variant for the integration of gas turbine units into the thermal scheme of steam-turbine energy units is to use the heat recovery steam generator thermal capacity for reheating the working fluid spent in the steam turbine with utilization of the remaining heat for feed water and main condensate heating. Compared with the most common schemes with displacement of regenerative heating to heat recovery steam generator, the proposed alternative variant allows increasing the thermal efficiency of the steam-turbine circuit. The analysis of gas turbine units energy characteristics showed the need to research the scheme and parameters of the steam reheating for heat-extraction energy units taking into account the operating modes of steam turbine. Object: steam-turbine energy unit T–165/210–130 with gas turbine topping (GT-topping) for reheating of the working fluid spent in the steam turbine with utilization of the remaining heat for feed water and main condensate heating. The aim of the research is to select scheme and calculate the optimal parameters of steam reheating as applied to the steam-turbine energy unit T–165/210–130 with GT-topping, analyze its main performances during the work on the heat schedule when steam reheating temperature changes in heat recovery steam generator. Methods: system analysis and mathematical modeling. Results. The authors have developed the mathematical model and program for calculating the proposed scheme and performed the features analysis associated with the organization of steam reheating in GT-topping heat recovery steam generator. Furthermore, we showed that the efficiency of heat-extraction energy unit with steam reheating can be increased by organizing steam reheating in GT-topping heat recovery steam generator. In addition, we determined that in this case, the highest efficiency of a steam-turbine energy unit with GT-topping during operation in the design heat-extraction mode is achieved, when steam reheating temperature is below the nominal value.

Three methods were explored to estimate the efficiency for the conversion of mechanical power to electrical power using synchronous generators in ships at low power factors. Generally, the generator efficiency data is provided by manufacturers as shop trial data and is measured by operating generators under power factor of 0.8 and 1.0. However, the efficiency of synchronous generators is not measured under low power factor of less than 0.8. In practice, onboard generators occasionally operate at low power factor and it is desirable to clarify their characteristics for power system designers of large vessels. By substituting the shop trial data into the proposed efficiency estimation formulas, the generator efficiency at low power factor was extrapolated. To evaluate the validity of these methods, the fuel consumption characteristics of diesel engines as prime movers was focused. The estimation of the generator efficiency was indirectly validated using a statistical analysis of long-term observational data of the generator in operation. As a result, the efficiency estimation method based on a power loss mechanism gave the most reliable result among the three estimation methods. The root mean squared error of the calculated specific fuel consumption was 3.5 g/kWh, which is approximately 1.66 % error rate.

To organize an efficient transport structure, modern road telecommunication systems provide information collection about the vehicle connected to the system and analyze it. The modern car in such a system is considered to be connected. Such information systems can collect information about the vehicle. This information includes its driving parameters, location, and the parameters of the vehicle systems state. After processing and analyzing this information, it is possible to form recommendations and control actions. These recommendations are used by the driver or an automated vehicle control system. This article describes the general principle of the operation of modern transport telecommunication systems. The car-to-car type of interaction protocols are highlighted in this system. Wireless communication technologies that allow this interaction to be implemented are described. One of the principles was developed, according to which the system can determine the optimal use of the vehicle resource and the aggressiveness of the driving style of a freight vehicle on the basis of an automated algorithm for issuing recommendations for driver actions. This principle is considered as exemplified by a series of load characteristics of a diesel engine. The principle of choosing the optimal series of recommendations to a group of drivers to optimize the movement of traffic through the car-tocar interaction has been formulated.

The reduction in environment pollutant emissions is one of the main challenges regarding ground transportation. Internal combustion engines, used especially in hybrid propulsion systems, may be a solution in the transition to fully electric cars. Therefore, more efficient engines in terms of fuel consumption, emission generation and power density must be developed. This paper presents research regarding the architecture of the combustion chamber of an internal combustion engine with opposed pistons. The aim of this research was to find a combustion chamber architecture that would enable the engine to perform close to the program target of: NOx < 3.5 g/kWh, smoke (FSN) < 1, specific fuel consumption (bsfc) < 198 g/kWh. Three variants of the combustion chamber’s architecture have been studied. After the experimental research, the conclusion was that none of them fully reached the target; however, significant improvements have been achieved compared with the starting point. As a result, further research needs to be carried out in order to reach and even exceed the target.

The current development trend of global civil aviation is the growth of passenger and freight traffic, which entails the consumption of jet fuel. Under these conditions, increasing the efficiency of jet fuel used is of great importance. Global energy consumption is constantly growing, and, first of all, the question of diversification of oil resources arises, resources from which the bulk of motor fuels is produced. Other types of raw energy sources (natural gas, coal, bio-mass) currently account for only a small part. However, an analysis of the development of jet fuels indicates that work is underway to obtain these from other sources of raw materials, especially bio-fuels. Much attention is given to obtaining bio-fuels from renewable sources – such as algae. The issue of the mass transition of civil aviation to alternative fuels is complex and requires the solution of intricate technical as well as economic issues. One of these is the assessment of the impact of new fuels on GTE performance. It is important to give an objective and quick assessment of the use of various types of fuels on the main characteristics of the engine – i.e., throttle and high-speed characteristics. In this case, it is necessary to take into account chemical processes in the chemical composition of new types of fuel. To assess the effect of fuels on the characteristics of a gas turbine engine, it is proposed to use a mathematical model that would take into account the main characteristics of the fuel itself. Therefore, the work proposes a mathematical model for calculating the characteristics of a gas turbine engine taking into account changes in the properties of the fuel itself. A comparison is made of the percentage of a mixture of biofuels and JetA1 kerosene, as well as pure JetA1 and TC-1 kerosene. The calculations, according to the proposed model, are consistent with the obtained characteristics of a gas turbine engine in operation when using JetA1 and TC-1 kerosene. Especially valuable are the obtained characteristics of a gas turbine engine depending on a mixture of biofuel and kerosene. It was found that a mixture of biofuel and kerosene changes the physicochemical characteristics of fuel and affects the change in engine thrust and specific fuel consumption. It is shown that depending on the obtained physicochemical properties of a mixture of biofuel and kerosene, it is possible to increase the fuel efficiency and environmental friendliness of the gas turbine engines used.

In this study, we aimed to determine the reliability of estimating the specific fuel consumption by using ANN instead of long and costly testing approaches. For this purpose, specific fuel consumption was determined at different axle loads, tire pressures and drawbar forces for a 60 HP tractor. In addition, the results were also estimated with the help of Artificial Neural Networks, which is one of the machine learning methods. The tests were carried out on the Tractor Draft Test Track. In the study, three different drive tire inner pressures (160 kPa, 120 kPa and 80 kPa), four different dynamic axle loads (1796 daN, 2076 daN, 2276 daN, 2476 daN) with adding extra loads and four different traction forces (500 daN, 1000 daN, 1500 daN, 2000 daN) were tested for their effects on specific fuel consumption. Specific fuel consumption values varied between 290.7-542.1 g/kWh depending on the draft force in the tests. Despite the 38% increase in the axle load, a 3.5% decrease occurred in the specific fuel consumption values. Specific fuel consumption values increased when tire inner pressure increased. Specific fuel consumption increased by 1.03% when a 100% increase in tire pressure was realized. In ANN, the most successful model was determined by trying different training algorithms, transfer functions and the number of neurons in the hidden layer. In the most successful network model, MAE, RMSE values for the prediction of specific fuel consumption were found to be 0.005331,0.007551 respectively. [ABSTRACT FROM AUTHOR]

A gas-steam turbine unit with a common gas-steam generating device and independent steam and gas turbines is considered. The gas-steam generating device is structurally two vertically arranged concentric cylinders. The space of the inner cylinder is the combustion chamber of the gas turbine, and the space between the concentric cylinders is the steam generating device. Water, compressed to high pressure and regeneratively heated to saturation, is sprayed onto the lower side of the heated surface of the combustion chamber and turns into saturated steam. In the upper part of the surface of the combustion chamber, the superheating of the vapor formed during throttling of the saturated liquid is carried out. After converting the main part of the water into saturated steam, which did not turn into steam during throttling, the lower main part of the combustion chamber surface is included in the superheating of the entire steam. Using a system of valves, isochoric processes of fuel combustion and steam superheating are provided. This makes it possible to regulate the temperature (pressure) of the gases entering the gas turbine blades, as well as the amount and parameters of the superheated steam produced. The proposed gas-steam turbine unit is devoid of numerous disadvantages, both gas turbine and steam turbine units, and most importantly, it is characterized by simplicity and mobility. Preliminary calculations of the idealized installation (without taking into account the inevitable thermodynamic and mechanical losses) have shown its high efficiency. At a natural gas consumption of 1 kg/s, a pressure of p0 = 2,2 bar and a temperature of t0 = 30 °C, its specific volume, recalculated to normal conditions, is 1.4 nm3 /s. Having adopted a ratio of 1:10 between the volumes of gaseous fuel and air entering the combustion chamber, it was required to supply 14 nm³ /s of air to the combustion chamber. Under these conditions, the power of the gas-steam turbine plant exceeded 33 MW with a thermal efficiency of 0,66 and a specific fuel consumption of 0,1066 kg/(kWh) [ABSTRACT FROM AUTHOR]

This study is motivated by the depletion of fossil fuels in nature, which is inversely proportional to the higher level of fuel oil consumption, so the need for alternative fuels, namely biodiesel. Biodiesel can be made using waste cooking oil because of its abundant quantity, low price, and not being reused. One of the efforts to achieve energy conservation and improve fuel quality is using bioadditives. A lemon essential oil can be used as a bio-additive because it is easily soluble in fuel and its oxygen-rich content can reduce the rate of fuel consumption. The process in this study is to produce biodiesel with waste cooking oil (WCO) using a transesterification process. Biodiesel samples containing the bioadditive lemon essential oil on B20 biodiesel with varying volume fraction (0%; 0.1%; 0.15%; 0.2%). In general, this research can be done in three steps. The first step is the characterization of the compound composition (GCMS) and functional group (FTIR) of diesel fuel, biodiesel, and lemon essential oil bioadditive. The second step is the characterization of the physicochemical properties (density, viscosity, flash point, calorific value) of B20 biodiesel with various concentrations of lemon essential oil bioadditive, then compared with SNI 7182:2015. The third step is determining the rate of fuel consumption in diesel engines. The results show that Biodiesel B20 with a volume fraction of 2% lemon essential oil bioadditive has a high ability to reduce the rate of fuel consumption. [ABSTRACT FROM AUTHOR]

Half of the world's population relies on biomass fuels for cooking and heating, which contributes to global forest depletion that leads to environmental and human health impacts. Although biomass consumption is unavoidable, using Mirt stoves save biomass fuel consumption and time for cooking. Currently, improved cooking stoves (ICS) are disseminating worldwide including sub-Saharan countries. However, studies on factors that influence the adoptions and fuel-saving performance of ICS were limited. This study was carried out to assess factors that determine the adoption and fuel use efficiency of Mirt stoves in Dilla district, Southern Ethiopia. Data were collected using questionnaires from 384 households. To test fuel use efficiencies a triplicate controlled cooking test (CCT) was made. The data gathered from questionnaires and CCT were analyzed using binary logistic regression and t-test statistical tools, respectively. The regression results revealed that marital status, household income and availability of stoves were significantly (P 0.05) difference in the length of time to bake a given amount of Injera and the amount of charcoal extracted. Our result suggested that improve cooking stoves like Mirt stove could ease the burden fuelwood collection of rural households and the efforts made to improve the adoption of Mirt stove could be successful when ICS dissemination programs consider socio-economic and market-related factors into account.

An increase in fuel utilization to internal combustion engines, variation in gasoline price, reduction of the fossil fuels and natural resources, needs less carbon content in fuel to find an alternative fuel. This paper presents a comparative study of various gasoline blends in a single-cylinder two-stroke SI engine. The present experimental investigation with gasoline blends of butanol and propanol and magnesium partially stabilized zirconium (Mg-PSZ) as thermal barrier coating on piston crown of 100 µm. The samples of gasoline blends were blended with petrol in 1:4 ratios: 20 % of butanol and 80 % of gasoline; 20 % of propanol and 80 % of gasoline. In this work, the following engine characteristics of brake thermal efficiency (BTH), specific fuel consumption (SFC), HC, and CO emissions were measured for both coated and non-coated pistons. Experiments have shown that the thermal efficiency is increased by 2.2 % at P20. The specific fuel consumption is minimized by 2.2 % at P20. Exhaust emissions are minimized by 2.0 % of HC and 2.4 % of CO at B20. The results strongly indicate that the combination of thermal barrier coatings and gasoline blends can improve engine performance and reduce exhaust emissions.

Biodiesel in the past, was once considered a fringe fuel. However today, the production and consumption of this fuel has grown as a sustainable and much more eco-friendly alternative to the Conventional diesel (Petroleum diesel), for diesel engines; if not in pure form, it will be in blends of different ratios, or as a fuel additive, to improve engine performance and ensure longevity. In this research, oil from Mango (Mangifera indica) seed was extracted through Soxhlet solvent process, and converted into biodiesel by the method of Transesterification. This process involved the reaction between the extracted oil and methanol at an optimal temperature of 60oC, and 1%w/v of the catalyst (KOH) concentration for optimal yield of biodiesel. The produced biodiesel was analyzed and evaluated by comparing its physical characteristics to that of Conventional (petroleum) diesel fuel. The properties analyzed were; Density, Heating value, flash point, specific gravity, viscosity, cloud point, water content and pour point. The biodiesel from mango seed oil (MSO) compared excellently well with the values obtained for the commercially available petroleum diesel, dispensed at government approved filling stations in Nigeria. The biodiesel so produced and characterized, was subsequently subjected to an engine test, in a four-stroke internal compression (IC), (diesel) engine loaded between 120 - 200 rpm, to determine its suitability as a fuel. The result was compared with the Conventional diesel characteristics in terms of brake power output, mass flow rate, thermal efficiency, and specific fuel consumption (SFC) and so on. The biodiesel results compared very well with most of the data generated on the conventional diesel, and satisfied the ASTM-D6751 and the EN14214 standard requirements for suitability as working fluid in an IC engine, especially with regard to SFC, which translates to the direct running cost of every diesel engine. [ABSTRACT FROM AUTHOR]

More than 70% of the plastic wastes come out the packing materials. This causes heart problems and cancer too in the later stages. The plastics started to blend in drinking water in a major percentage. Recycling of the existing waste plastic is the only major way so that we can reduce this harmfulness to the globe. Here we have made use of polythene which plays a part of 33.5 percentage of the total plastic waste and is the highest waste among them. These wastes are mechanically separated and converted to plastic oil through pyrolysis. These oils are blended with the existing diesel in about 6 to 12 percentage for conversion to biodiesel and tested on a single cylinder four-stroke diesel engine for its performance. The exhaust gas which comes out is tested for its emissions and compared with diesel specific fuel consumption (SFC) and emissions. [ABSTRACT FROM AUTHOR]

Greenhouse gas emissions and atmospheric pollutants, economic savings, as well as alignment with the new rules of the shipping industry's leading is a new concern. In order to meet and achieve these goals, many efforts have been made. In this paper, some methods for reducing fuel consumption, including optimization of floating trim, have been considered in design draught. In this regard, the body resistance of model of the KCS container ship is calculated in design draught; This analysis was performed by numerical solution and experimental test for -0.1 to +0.1 trim range. And the results of ship model analysis was generalized to the main body. In this regard, the mathematical model of ship propulsion system is implemented in the MATLAB-Simulink software; and by using this model for different trims, rates of ship specific fuel consumption presented. According to the results of modeling and simulation of the floating body, a reduction of 1.5% of fuel consumption has been achieved due to optimization of the trim.

One of the promising ways in environmentalizing marine internal combustion engines is the neutralization of harmful substances in exhaust gases through particular gas recirculation (EGR-technology). However, the use of such techniques conflicts with the engine's energy efficiency. In the work presented, the scheme-design solution of the exhaust gas recirculation system with using the heat of recirculation gases by an ejector refrigeration machine for cooling the air at the intake of ship's main engine is proposed. The effect of using the heat of recirculation gases for cooling the air at the intake of the engine is analyzed taking into account the changing climatic conditions for a particular vessel's route line. It is shown that the use of an ejector refrigeration machine reduces the air temperature at the entrance of the main engine by 5-15 ° С, which reduces the specific fuel consumption by 0.5-1.5 g/(kW∙h). This reduces emissions of harmful substances when the engine is running with recirculation of gases, in particular, NOx by 30-35%; SOx by 10-12%.

The first stage of implementation of the "Energy Strategy up to 2030" is finished in 2015. Estimated implementation of the indicator parameters of the first stage (2008-2015g): power consumption, power generation, power inputs, power structure, specific fuel consumption for electricity and heat, the need for fuel. For a number of indicators of the Energy Strategy are not achieved even limits, for some indicators deviations is minimal. In general, the phase assignment is not fulfilled, and it is obvious that the following steps should be adjusted downwards.

There are many ways and methods to reduce exhaust gases emissions on modern ships. One of the most effective ways to reduce NOx and SOx emissions is to use of exhaust gas recirculation (EGR technology). The EGR system disadvantage is an increase in back pressure through additional pressure losses in the scrubber and heat exchanger, which entails an engine fuel efficiency deterioration. Creating a reliable and efficient heat exchanger for cooling recirculation gases is a complex task due to deposits and pollution emitted by these gases. In the present work, the jet apparatus effectiveness named aerothermopressor is analyzed in the scheme with exhaust gases recirculation of the ship low-speed two-stroke engine. Aerothermopressor is a two-phase jet for contact disperse cooling, in which by increasing the heat from the gas stream the gas pressure and cooling are increased. The calculation of the characteristics of the engine was carried out, both in nominal, and in operating modes and in all possible range of partial loads. The installation of the aerothermopressor before the scrubber is proposed, which allows reducing engine thermal load. Increasing the pressure in the aerothermopressor by 0.2-0.4 ∙ 105 Pa (6-12%) allows reducing the back pressure in the gas exhaust system and thus reducing the load on the exhaust gas recirculation fan and when the engine load is higher than 75% in the cold zone, the fan is not needed, which additionally allows to reduce the specific fuel consumption. The parameters of the exhaust gases that are going to be recirculated and the processes of their gas-dynamic cooling in the aerothermopressor are based on the developed technique and program using the thermodynamic and gas dynamics equations. The proposed scheme-design solution allows at a high environmental friendliness of the existing exhaust gas recirculation system to provide a certain reduction in specific fuel consumption. It was determined that the engine specific fuel consumption has been decreasing when the aerothermopressor is used to 2.5-3.0 g/(kW·h) (1.5-1.7%).

Introduction. The results of estimating greenhouse gas (GHG) emissions by a vehicle fleet are described, using the COPERT-4 methodology and the baseline data contained in 1-BDD form, concerning the number of vehicle fleets in Russia and three options for detailing the fleet structure by the fuel type and ecological class in different organizations. Such data is not provided in the forms of state statistical reports and is generated by the researchers.Materials and methods. Various approaches to the structuring of the park by the fuel type and the ecological class give a slight variation in the values of GHG emissions’ gross (up to 4.1%), which confirms the correctness and approaches’ validity to the generation of the required initial data. The authors introduce the concept of total conditional transport work in order to adjust the values of the average annual mileage to the generation of the required initial data in the calculation of GHG emissions gross by the fleet of cars. Moreover, the value of total conditional transport work for all considered GHG variants should be the same.Results. As a result, if such adjustment is not made, the difference between the obtained calculated values of GHG emissions gross by the vehicle fleet for different authors would reach 25-30%. Discussion and conclusions. The reliability of the GHG emission values estimation is confirmed by the indirect method or by comparing the data of statistical reporting on the volumes of motor fuel consumption depending on different consumers in the fuel and energy balance, and on the fuel consumption values, and on the greenhouse gas emissions gross by the COPERT-4 method.

This paper presents an experimental study carried out in an industrial furnace for frits production using different configurations of burners based on different combustion techniques such as enriched air combustion, flat-flame oxy-combustion and preheater air combustion. The residence time of combustion gases inside the furnace also was modified. Several combustion configurations were tested and its effects on productivity and thermal energy specific consumption and efficiency were determined. The results show that higher residence time of the combustion gases can decrease significantly the specific consumption of fuel, while the change of the burners and combustion techniques did not show significant effects on decreasing the energy consumption. However, it is highlighted that the oxy-combustion flat-flame burners produced the lowest specific consumption of fuel. Even though the experiments were conducted in a furnace for frit production, the corresponding results can also be applied to guide or improve other industrial high temperature processes.

Determination of specific fuel consumption of air-breathing engines is one of the problems of modeling their performance. As a rule, the estimation error of the specific fuel consumption while calculating air-breathing engine performance is greater than that of thrust. In this work, this is substantiated by the estimation error of the fuel-air ratio, which weakly affects thrust but significantly affects the specific fuel consumption. The presence of a significant error in the fuel-air ratio is explained by the use of simplified methods, which use the dependence of enthalpy as a function of mixture temperature and composition without taking into account the effect of pressure. The developed method to improve the calculation accuracy of specific fuel consumption of air-breathing engines is based on the correction of the fuel-air ratio in the combustor, determined by the existing mathematical models. The correction of the fuel-air ratio is made using the dependences of enthalpy on mixture temperature, pressure and composition. The enthalpy of the mixture is calculated through the average isobaric heat capacity obtained by integrating the isobaric heat capacity, depending on mixture temperature, pressure and composition. The calculation accuracy of the fuel-air ratio was verified by comparing it with the known experimental data on the combustion chamber of the General Electric CF6-80A engine (USA). The average calculation error of the fuel-air ratio does not exceed 3 %. The developed method was applied for correcting the specific fuel consumption for calculating the altitude-airspeed performance of the D436-148B turbofan engine (Ukraine), which made it possible to reduce the estimation error of the fuel-air ratio and specific fuel consumption to an average of 3%. [ABSTRACT FROM AUTHOR]

This paper presents an experimental study carried out in an industrial furnace for frits production using different configurations of burners based on different combustion techniques such as enriched air combustion, flat-flame oxy-combustion and preheater air combustion. The residence time of combustion gases inside the furnace also was modified. Several combustion configurations were tested and its effects on productivity and thermal energy specific consumption and efficiency were determined. The results show that higher residence time of the combustion gases can decrease significantly the specific consumption of fuel, while the change of the burners and combustion techniques did not show significant effects on decreasing the energy consumption. However, it is highlighted that the oxy-combustion flat-flame burners produced the lowest specific consumption of fuel. Even though the experiments were conducted in a furnace for frit production, the corresponding results can also be applied to guide or improve other industrial high temperature processes. [ABSTRACT FROM AUTHOR]

This study analyzes the performance of the diesel engine in terms of power, torque, specific fuel consumption, and thermal efficiency using diesel and pyrolysis oil. The waste plastic oil (WPO) used in this research was produced through a pyrolysis process using raw materials from Low-density Polyethylene (LDPE) mixed with diesel fuel in volume ratios WPO10, WPO20, WPO30, WPO40, and WPO50. In addition, a performance test was carried out on the single-cylinder diesel engine test bench. The results showed that performing the diesel engine with the addition of WPO increased the average power and torque by 5% and 3%, thereby producing a higher heating value. Furthermore, the concentration of WPO also reduces the level of specific fuel consumption to be more efficient, with a decrease in thermal efficiency. In conclusion, plastic waste pyrolysis oil is a promising alternative fuel applicable to a diesel engine.

The rapid increase of diesel engines and diminishing of diesel fuel creates a challenge for researchers to find alternative fuel. The present experiment is performed on a 3.5 kW diesel engine. Here, diesel is replaced with pure lemongrass oil (LGO) of10%, 20%, and 30% by volume with diesel. The obtained data from the experimental work may exhibit the Brake Thermal Efficiency (BTE) of LG20 equivalent to pure diesel. The specific fuel consumption (SFC) of LGO blends shows an increase compared to diesel, due to the lower heating value for LGO blends. On the other hand, LGO blends show lower emissions of NOX, due to the lower peak flame temperature. When compared to the other samples, the LG30 gives a maximum reduction in NOX emissions; of 10.33%. When compared to biodiesel blends, diesel fuel shows a significant increase in the Net Heat Release rate (NHR). [ABSTRACT FROM AUTHOR]

Steam power plants have a considerable potential to meet the growing energy demand, but its dependence on conventional fossil fuels has hampered its viability. One of the ways to minimize fuel consumption and upgrade the performance of a Rankine cycle is by incorporating closed feedwater heaters(FWHs). The datasets contained in this paper are thermodynamic performance analysis carried out on reheat – regenerative steam power plant with FWHs using CyclePad V2.0 software. The thermodynamic performance indices assessed are thermal efficiency, network output, heat rate, fuel consumption, boiler efficiency and specific steam consumption. Result obtained show that an increase in the number of FWHs decreases the fuel consumption, heat rate, heat rejected in condenser and heat input to the cycle. This effect invariably can lead to a reduction in operating cost and environmental impacts.

The dependence of the specific fuel consumption of the ship diesel-generator set on the generated electric power and the power factor is given. An algorithm for load distribution between parallel marine diesel generator sets is given, taking into account the dependencies of the specific fuel consumption on the generated power and the power factor of each marine diesel generator set. The possibility of using neural networks to solve the problem of minimizing the specific fuel consumption for parallel operation of ship diesel-generator sets in the steady state mode is considered. A neural network model for reducing fuel consumption is proposed by distributing the total electric load of a ship power plant between diesel generators operating in parallel. Such a model, based on the database obtained in the training process, which is implemented by microprocessor controllers with the algorithms of searching for a combination of capacities inherent in them for each of the parallel running generator, at which the minimum flow is reached, independently determines how it is necessary to load the units operating in parallel, to achieve a minimization of fuel consumption; and periodically checks the correspondence between the estimated (calculated) and the actual fuel costs, which ensures the control of the technical condition of the mechanisms.

Introduction Nowadays, the best method for fertilizing trees is spot treatment via hole-digger. Conventional mechanical hole-diggers have several drawbacks such as auger’s non-continuous and limited speeds due to using a mechanical gearbox, and risks of getting stuck inside the hole and motor reaction force to the operator. On the other hand, a three-point hitch hole-digger has problems such as the lack of maneuverability in confined spaces and high prices. Meanwhile, preparation of these hole-diggers by most farmers and gardeners has no economic justification. Thus, in this research it has been aimed to handle the mentioned problems and to optimize the working quality of hole-diggers via designing and manufacturing a new hydraulic hole-digger. Materials and Methods To start design the machine, displacement volume and power requirement of the hydro-motor and consequently displacement volume requirement of a hydro-pump were calculated using the appropriate formulas (70.83 cm3, 2.3 kW & 7.5 cm3, respectively). According to available hydro-motors and hydro-pumps in the market and using obtained values of displacement volume, an orbital hydro-motor, BMR-80 model with the maximum torque of 220 N.m and an external gear pump REXPORT-2APF8 with displacement volume of 8 cm3 and flow rate of 12 L.min-1 were chosen. In the following, hydro-pump’s parameters were used to select the internal combustion engine. The engine power requirement was 2.875 kW (3.85 hp); thus according to the available engines in the market, a single cylinder gasoline engine, WX168F-1 model that made in Kato company of China with 6.5 hp power and maximum speed of 3600 rpm was chosen. To transmit the power from the engine to the hydro-pump, a coupling DK-42 model was used. Also, two pressure gauges, LB-250 model with maximum pressure of 250 bars were used in the entrance and the exit of the hydro-motor. An hydraulic oil tank with total volume of 24 liters was made from a sheet metal with thickness of 3 mm. The helical auger used in this research, was made in china by LIONS Company with cone tip, total diameter of 200 mm and pitch of 180 mm. The fabricated digger has a working depth and diameter of 30 cm & 20 cm, respectively; rotational speed between 100-160 rpm and maximum power equal to 6.5 hp. In order to evaluate the stress distribution in the auger set, the static analysis based on maximum dynamic torque exerting on auger’s axle and maximum dynamic force exerting on auger’s blades, was used in SOLIDWORKS 2013 software. The maximum force 214.07 kgf (2100 N) proportional to the maximum exerting torque (210 N.m) from soil to the edge of the auger’s blade were considered in the modelling. Farm experiments were carried out in two citrus gardens with silty-clay and sandy-loam texture based on factorial test in Completely Randomized Design with three replications. Soil moisture content as high and low humidity levels (24.85% and 16.12% in sandy-loam and 25.95% and 16.48% in silty-clay) as the first factor and soil depth as the second factor varied in three levels of low, medium, and high (10, 20 and 30 cm), respectively. The measured parameters consisted of specific fuel consumption, machine efficiency, auger torque, auger power and used energy. To determine the auger’s torque, the oil pressure measurement method with two manometers was used in the entrance and the exit of the hydro-motor. After measuring the time and power needed to dig pits, for determining the used energy, the area under the power-time graph was calculated in Excel software. Also, to determine the fuel consumption during the experiments, the filled fuel tank method was used. Data analysis including analysis of variance (Anova), mean comparisons and interaction between the parameters were performed using the SPSS 22 software. Results and Discussion The numerical stress analysis results of the auger showed that the maximum von - Mises stress is occurred in the position of the blade-auger axis connections, with a magnitude of 86 MPa. The obtained experimental results in this study indicated that influence of soil depth and moisture content on the measured parameters were significant. in both soil textures and the influence of soil moisture on machine efficiency was non-significant in the silty-clay texture. With increasing soil depth, measured parameters excluding machine efficiency were increased in both soil textures. In high depth and also in low moisture, regarding to the increasing soil bulk density and shear strength, more torque was needed for the rotating auger in the soil that this has led to an increasing in specific fuel consumption of the device. Regarding the results obtained in this study, minimum specific fuel consumption value of the device (0.0014 liter pit-1) was obtained at the low working depth (10 cm) and the high soil moisture (25.95%) in the silty-clay soil. The hole-digger working capacity at 30 cm working depth and soil moisture content as high and low humidity levels in silty- clay obtained equal to90 and 88 pits per hour and in sandy-loam obtained equal to 101 and 95 pits per hour, respectively. Also, the maximum device’s power (2.548 kW) occurred in deep soil (30 cm) and low soil moisture in silty-clay texture. Conclusions Stress analysis and field qualitative observations results indicated that the fabricated device has sufficient resistance and strength against maximum torque from tested soils. Field evaluation of the fabricated machine showed that pit digging operations in soil is not appropriate in low moisture content because of the high fuel consumption and environmental pollution issues.

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An experimental investigation on the gasification of corncobs was conducted in an 18 kW pilot-scale fixed bed system for power generation. The main objective was to determine the effect of gasifying corncob mixtures with fines content (particle size below 10 mm) on the performance of the system. To achieve the objective, a 2× 3 factorial arrangement was developed. The analysis considered three resistive loads connected to the generator (4, 8, and 12 kW) and two different size ranges of biomass (one with 100% of chips within the actual recommended size (10–40 mm)) and the other with a content of 15% of fine particles (particle size below 10 mm). An increase of 15% in fine material content in the feedstock and a stable electricity demand close to the rated capacity, significantly increased the temperature of the process and decreased the mean specific fuel consumption – SFC (2.06 kg/kWh at 67% of rated capacity). H 2 and CO production increased by increasing reactor temperature, reaching concentrations of 16.7% and 17% respectively at the higher resistive load (12 kW). Cold gas efficiency varied in the range of 33.7%–37.0%, increasing slightly with the blend of fines content and higher applied load. • Corncobs were tested in an 18-kW downdraft gasifier for power generation using different resistive loads (4, 8, and 12 kW). • Gasification performance was analyzed using biomass with a fraction of fine particles (particle size below 10 mm). • Gasification temperature, specific fuel consumption, cold gas efficiency, and gas composition were investigated. • Corncob mixtures with 15% of fine materials led to good syngas compositions without affecting the performance of the process. [ABSTRACT FROM AUTHOR]

Energy empowered world increases energy need. Fossil fuels depletion rate increases day by day necessity in search of alternative fuel to fulfill energy requirements of the world. Biodiesel offers the best energy alternative in the modern world. Biodiesel can be a substitute for diesel fuel. In this study, biodiesel is prepared by blending Cottonseed oil with diesel. Raw vegetable oil has some unfavorable physical and chemical properties. Nanoparticles are introduced to stabilize the biodiesel and improve properties by enhancing the quality of the fuel. In this investigation, Cerium oxide is blended with Biodiesel, by using its engine performance and emission characteristics are analyzed and compared with existing diesel. Biodiesel is used as an alternative to diesel. The Cottonseed oil blended Biodiesel is enhanced in properties by addition of Cerium oxide nanoparticle to achieve high calorific value fuel and reduce harmful gases forming in exhaust gas let to the atmosphere. The Biodiesel is blended at different proportions of cottonseed oil and diesel with Cerium oxide as nanoparticles. Experimentation for performance and emission characteristics investigation is done on varying loads. Biodiesel is provided as an alternate solution for fuel demand and pollution less fuel. [ABSTRACT FROM AUTHOR]

In this study, a biodiesel was produced from blending vegetable and animal sources with diesel and diesel-ethanol using a motor-generator set to evaluate its performance and emission characteristics. Fifteen and twenty percent of animal-vegetable biodiesel were added to each diesel-ethanol blend. A motor-generator test was conducted for each mixture; each sample was subjected to resistive loads from 2 to 5 kW with six repetitions. The physicochemical properties met the national standard guidelines, while the best specific fuel consumption (SFC) was observed for the 15% biodiesel-1% ethanol (B15E1) blend at the load of 5 kW with 327.069 g kW−1 h−1, followed by diesel (334.875 g kW−1 h−1). The exhaust gas temperature behaved differently depending on the ethanol concentration; it was lower when the concentration of added ethanol was higher. The NO emissions decreased while the SO2 emissions increased as the ethanol concentration increased. [ABSTRACT FROM AUTHOR]

The influence of ambient temperature and moisture content on the performance of Transcorp Power Plant, Ughelli, Delta State, Nigeria was investigated with the aid of a digital psychrometer. The simulation was done using codes developed on MATLAB R2017a and the results show that compressor power consumption increased by 1.65% for 0.7% rise in temperature, and 0.50% for 71.4% rise in moisture content. The specific fuel consumption also increased with increase in temperature where a 1.71% rise in ambient temperature resulted in a 0.15% rise in specific fuel consumption but it decreased by 0.49% for a 41.7% rise in moisture content. A 1.62% rise in temperature led to a 0.13% drop in net power output and a 29.4% rise in moisture content resulted in a 0.48% drop in net power output. Thus gas turbine plant operates optimally in areas with low ambient temperatures and high moisture content. [ABSTRACT FROM AUTHOR]

A four-section miscanthus rhizome planter machine was equipped with a ploughshare and cover discs at the outer units and with ploughshare and compaction wheels arranged in V at the central units of the machine. Under these conditions, experimental determinations were made regarding the tensile strength (kN), the power required for towing (kW) and fuel consumption (l/ha), for three working depths (6, 9 and 12 cm) and different working speeds (between 1.27 and 2.65 m/s). Field results showed traction force values between 4.90-8.51 kN for planting depths of 6 cm, respectively between 6.90- 8.35 kN for depths of 9 cm and between 8.38-8.52 kN for 12 cm depths. Fuel consumption showed values between 2.96- 5.18 l/ha at planting depths of 6 cm, between 3.30-4.07 l/ha for depths of 9 cm, respectively between 4.4-5.2 l/ha for planting depths of 12 cm. It was found that there is no well-defined rule regarding variation of traction parameters with planting depth, especially since the average travel speed could not be maintained at the same value for each sample, and the soil probably had wetter areas or with different resistance to the opening of the trench. [ABSTRACT FROM AUTHOR]

Determining the optimal structure of the tillage combine for working in a particular company is a very difficult task due to many factors. While searching for the optimal choice, it is necessary to strive for having fewer combines in operation, reduce the fuel costs and compensate damages due to changes in agrotechnical terms and soil compaction during the combines’ operation. In this article it is proposed to apply the Monte Carlo simulation for solving this issue. As a result of the analysis of models, it was observed that all combines can be divided into separate efficiency groups and form certain tillage complexes. After the analysis of these complexes, it was proposed to replace the tillage tools, which led to further reduction in total costs. So the transition to non-mouldboard technology in both high-efficiency and low-efficiency combines will lead to cost savings by 45%, and the introduction of new tools will reduce the fuel consumption by 61-64%. For high-efficiency machine complexes, non-mouldboard technology allows the reduction of the optimal number of aggregates by 25-32%. At the same time, the introduction of new tillage combines will reduce the number of operating combines by 50-58% due to reduced resistance and the combination of technological operations.

The main aim of this article is to present the experimental data of the operating parameters and emissions obtained in a small gas turbine equipped with a variable area nozzle system. The variable area nozzle is proposed as a means of improving turbine efficiency, which has been a popular trend in recent development of gas turbine engines. Based on turbine vane twisting, the proposed variable area nozzle system was developed and implemented in GTM-120 small gas turbine. The concept was experimentally investigated on the engine test bench and engine working parameters were accurately measured. Experimental research shows that significant improvement of engine specific fuel consumption (up to 4%) and specific thrust (up to 5%) has been achieved. Additionally, reduction in CO emissions (up to 64%), NO emissions (up to 7%) and NO2 emissions (up to 53%) has been noted. Experimental research results were compared with analytical engine model showing moderate, qualitative agreement between the experimental data and model outputs. Main advantages of variable area nozzle system and design challenges of the proposed concept are discussed in the article summary. [ABSTRACT FROM AUTHOR]