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Hydraulic valves are one of the most studied component in the fluid power field since they control the flow in complex systems. Directional control spool valves allow the shifting of the flow to different users through the displacement of a spool, which slides inside the valve’s core opening and closing the flow paths. The research presented in this paper shows the designing of a directional spool valve using a three-dimensional fluid dynamic approach. The valve is a size 10, with pressure up to 350 bar and standard flow rate up to 160 l/min. The numerical approach has been validated through experimental tests on a preliminary valve, already available on the market, which has same performance and size. The final design of the new valve has been then studied with a FEA approach in order to minimize issues related to the body deformation. The final result is a new valve designed by minimizing the prototyping requirement and development costs with lower pressure drop and performance equal or superior to valves which have had a longer prototyping processes.

Gerotor pumps are widely used on engine hydraulic circuits. The design of these pumps is mainly focused on the study of the leakages through the rotors. Modelling or experimental techniques can be adopted during the components design and optimization phases. The study presented in this paper shows results of a research study made on a gerotor pump. The study has been approached with modeling and experimental techniques. The pump has been tested on a hydraulic bench of the University of Naples “Federico II”. Tests have allowed the complete characterization of the pump including in worst conditions like cavitation. In fact, calibrated orifices have been installed on the suction and delivery side of the pump forcing the cavitation. This research is focused on the detection of the cavitation that, as well known, is induced by the low pressure at pump suction, by the presence of air in the pumped oil, by the sloshing of the oil inside the sump and by the recent reduction of sump capability (to reduce maintenance costs). The experimentation phase has been followed by modeling; an accurate model of the pump has been built using the commercial 1D software GT-SUITE. The code developers have added new applications to replicate, with the best accuracy, the experimental data especially in cavitating conditions. The model results have been compared with the experimental data showing a good agreement. The model is able to correctly predict the pump performance including delivery flow rate, total power loss, volumetric efficiency and temperature influence.

In Campania region, southern Italy, a National Interest Priority Sites (NIPS) was identified: “Litorale Domitio-Agro Aversano” NIPS L.426/98, that includes a large part of the polluted agricultural land, belonging to more than 61 municipalities in the Naples and Caserta provinces. This second paper represents an analysis developed for a LIFE project (LIFE11/ENV/IT/275–ECOREMED): “Implementation of Eco-Compatible Protocols for Agricultural Soil Remediation in Litorale Domizio-Agro Aversano NIPS”. The contribution of this second paper to the above-mentioned LIFE project consists in the appraisal of the air quality state in this NIPS area, estimating the pollutant concentrations of the main air pollutants (CO, VOC, NO X and PM 10 ) in the area under investigation due to the principal industrial systems (namely punctual sources) and to the main diffused sources. All entropic activities which determine emissions in the atmosphere, in fact, depending on the distance from the areas under examination, could contribute to the soil qualification. The assessment of the air quality to local scale was carried by integrating the data of emission inventory in the NIPS area, that was estimated and reported in the first paper (Part 1), with elaborations of a Gaussian dispersion model.

Nowadays, the application of a PAT (Pump as Turbine) has been developed in several applications as pressure dropping valve. Generally, pump manufacturers do not provide the characteristic curves of their pump working as turbine and researchers have the objective of build a model to predict the turbine operation of pumps for energy recovery schemes. This paper shows a methodology based on a mathematical model of a centrifugal pump used as a PAT in an urban hydraulic network, to solve this kind of problem. The model was built up, starting from the real geometry, with a commercial tridimensional code, which is particularly suitable to simulate pumps and valves. The aim of this paper isthe investigation on the possibility to use a simulation methodologyto obtain the inverse characteristic of a commercial centrifugal pump. First, the model results were compared with the data declared by the pump manufacturer and after it was used to obtain the inverse characteristic (PAT mode). Furthermore, an experimental test bench was used to obtain the reverse mode pump characteristic, in terms of flow-rate/head. In both cases, the simulation model showed good accuracy, there is a low difference between simulated results and manufacturer/experimental data. The model results, which represents the first step of this activity, revealed that it is possibleto obtain the pump characteristic in reverse mode, which is not declared in the commercial pump datasheet.

In Campania region, southern Italy, a National Interest Priority Sites (NIPS) was identified: “Litorale Domitio-Agro Aversano” NIPS L.426/98, that includes a large part of the polluted agricultural land, belonging to more than 61 municipalities in the Naples and Caserta provinces. This paper represents a synthesis of a study developed for a LIFE project (LIFE11/ENV/IT/275–ECOREMED): “Implementation of Eco-Compatible Protocols for Agricultural Soil Remediation in Litorale Domizio-Agro Aversano NIPS”. As well known, the pollutants of the air may have an impact on the soil pollution; the contribution of the paper to this LIFE project is to provide the environmental characterization of the area, estimating the total annual emissions of the main air pollutants (CO, VOC, NOX and PM10) in the area under investigation, with municipal spatial disaggregation. The amounts of air pollutants emitted from various sources in this area were obtained through direct and continuous measures for the principal industrial systems, while for diffused sources the emissions were estimated on the basis of opportune activity indicators and fixed emission factors concerning specific emissive activities.

Diesel engines are worldwide used as a primary power source not only in motor vehicles, but also in off-road engine applications. Two-stroke Diesel engine is most commonly seen in applications demanding a large power output, such as ships and electric generation plants. The use of biofuels has increased during the last years in response to concerns about climate change and to increase security of supply. In this paper some results obtained with a 2-Stroke 6V53 Detroit Diesel (5.22L displacement, 150 kW at 2800 rpm) fueled with a commercial diesel fuel and biodiesel (100%RME) are discussed. CO, NO/NOx, CO 2 and particulate matter (PM) have been sampled at 1 Hz in different load conditions and fuel consumption has been measured. A catalyzed Diesel particulate filter (DPF) has been also installed at the exhaust to reduce PM emissions and the influence of fuel quality on emissions and fuel consumption was analyzed. The installation of DPF has involved an average of less than 10% fuel economy penalty for both tested fuels. A passive DPF system can be easily installed at the exhaust of in-use engine and it permits to reduce more than 90% PM emissions.

The object of this study is to investigate the effect of ethanol–gasoline blends on CO and HC cold start emissions from a four- stroke motorcycle. Nowadays, due to catalyst improvements and efficient electronic mixture control, a significant part of the total emissions during a trip takes place during the cold phase. The employ of alternative fuels could be one of means to lessen the cold-start emissions from two-wheeler engines: ethanol is known as potential alcohol alternative fuel for spark ignition engines, which can be blended with gasoline to increase oxygen content and then to decrease CO and HC emissions. From this considerations, an experimental-analytical investigation was performed on the exhaust cold extra emissions of one motorcycle belonging to the Euro-3 legislative category. The study explains a calculation procedure to model the cold start transient behavior of motorcycles in order to evaluate the impact of ethanol addition (10, 20 and 30 vol.%) on cold start emissions compared with a reference commercial gasoline. Results of the tests indicate that CO and HC cold start extra emissions by using ethanol–gasoline blended fuels decrease compared to the use of unleaded gasoline. Emission factors during the cold start transient were quantized as a function of the ethanol percentage in the blended fuels.

The aim if this paper is the analysis of a lubrication circuit adopting two simulation models to study the influence of three different lubrication oils. First, the oils pump performance were analyzed with a tri-dimensional simulation model, realized with the commercial code PumpLinx ® , which allowed to obtain the performance curves of the oil pump, varying the oils. Then the lubrication circuit was studied with a 1D model, realized with the commercial code LMS AMESim ® , and the behaviour of the lubrication circuit was analyzed in terms of pressure drops and components oil consumption. The adopted oils were: 0W30; 5W40 and10W60. In previous activities, both models showed good correlation with experimental data. Analyzing the models results, it was noted that the pressure behavior in the lubrication circuit is highly influenced by the oil, especially for low engine speed and high temperatures. The adopted methodology, that couples mono-dimensional and tri-dimensional models, allowed to analyze the oil influence in a lubrication circuit, avoiding excessive computational cost, but with an acceptable accuracy