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The main purpose of this paper was to determine and compare the boundary conditions of heat transfer on the cooled surface of a cylindrical sensor made of Inconel 600 alloy while cooling with a water jet, water spray and air-assisted water spray under high-temperature conditions. The inverse method for the heat conduction equation was used to determine the boundary conditions. Experimental tests were carried out, including temperature measurements at several points inside the cylinder while cooling with all the tested systems from a temperature of 900 °C for three values of water pressure: 0.05 MPa, 0.1 MPa and 0.2 MPa. Temperature measurements were used as the input data to identify the heat transfer boundary conditions. The temperature field of the axially symmetric sensor was determined using the finite element method. The boundary conditions were determined as average values of the heat transfer coefficient and heat flux and local values of the heat transfer coefficient. A comparison of the amount of thermal energy dissipating from the sensor surface as a result of boiling and a forced single-phase convection is also presented in the paper. The highest uniformity of cooling was obtained during air-assisted water spray-cooling. [ABSTRACT FROM AUTHOR]

The main purpose of this paper was to determine and compare the boundary conditions of heat transfer on the cooled surface of a cylindrical sensor made of Inconel 600 alloy while cooling with a water jet, water spray and air-assisted water spray under high-temperature conditions. The inverse method for the heat conduction equation was used to determine the boundary conditions. Experimental tests were carried out, including temperature measurements at several points inside the cylinder while cooling with all the tested systems from a temperature of 900 °C for three values of water pressure: 0.05 MPa, 0.1 MPa and 0.2 MPa. Temperature measurements were used as the input data to identify the heat transfer boundary conditions. The temperature field of the axially symmetric sensor was determined using the finite element method. The boundary conditions were determined as average values of the heat transfer coefficient and heat flux and local values of the heat transfer coefficient. A comparison of the amount of thermal energy dissipating from the sensor surface as a result of boiling and a forced single-phase convection is also presented in the paper. The highest uniformity of cooling was obtained during air-assisted water spray-cooling.

Direct water spraying (DWS) is an approach similar to ablation casting using direct impingement of water spray on the solidifying casting but is modified in that it no longer relies on eroding removal of the sand bound by water-soluble binders. A removable part of the sand mold is withdrawn during the process, and water is directly sprayed on the exposed casting surface. Two commercial casting Al alloys, i.e., A413 with short to zero and A356 with a wider freezing range, were processed by the DWS method. Comparison of the conventional and DWS-processed castings with respect to the microstructure and mechanical properties was evaluated via computer-aided thermal analysis, metallography, and tensile testing. The average ultimate tensile strength (UTS) increased from 126 to 193 MPa in A356 and 139–159 MPa in A413 by applying the DWS method. The elongation was increased from 2.8 to 11% in the DWS A356 and from 1.8 to 5% in the DWS A413. The secondary dendrite arm spacing (SDAS) was decreased from 80 µm in A356 to 44 µm and from 68 µm in A413 to 32 µm in the respective DWS-processed counterparts. The experimental results confirmed that a longer freezing range is more favorable with the DWS process, producing improved castings with higher tensile properties. [ABSTRACT FROM AUTHOR]

This paper presents an evaluation of a system aiming at estimating water depths on a road surface. Using accelerometers, the system records the vibrations of a wheel arch liner due to impacts of water droplets. The system setup, including the location of the accelerometers on a wheel arch and the data acquisition, is described. Tests were performed with a passenger car on various road surfaces and at different vehicle speeds and water depths. Signals recorded by the accelerometers are filtered and processed. The link between the acceleration amplitude, the water depth, and the vehicle speed is consistent with results from previous studies. The effect of the surface texture is less obvious and needs further investigations. A mathematical model has been developed to relate the acceleration amplitude to the water depth. The potential application of the developed system to on-board evaluation of pavement wetness, and consequently the pavement skid resistance, is discussed. Perspectives for driver assistance, or more generally, for autonomous driving to improve traffic safety, are also highlighted. [ABSTRACT FROM AUTHOR]

A zebra crossing is a road marking indicating a crossing path for pedestrians. Zebra crossings are directly used to signal drivers to stop at the line boundaries. Because the zebra crossing functions as a crossing area, pedestrians and motorized vehicle drivers must understand and obey existing traffic signs. According to data from the WHO (World Health Organization), 270,000 pedestrians die every year or around 22% of all victims who die due to road accidents. An ESP32-Cam microcontroller, an E18-D80NK Infrared Proximity Sensor, water spray and buzzer approaches, and the prototype development method were used to design a system for detecting crossing violations at zebra crossings to address this issue. The Infrared Proximity sensor will automatically detect when a crossing violation occurs, then the water spray will spray water, and the buzzer will make a sound as a warning sign to obey traffic. ESP32-Cam functions as an image capturer if a crossing violation has occurred and is automatically sent to the Telegram Bot. The confusion matrix test tested the research results with an accuracy value of 83.33%, a precision value of 83.33%, and a recall value of 88.23%.

• Validation of numerical models is presented by comparison with experimental results. • Influences of mass flow rate with different water spray schemes are discussed. • Influences of hydrogen ration of exhaust gas are illustrated. • Influences of vertical panel height on the cooling effect are analyzed. The thermal–hydraulic performance of flame deflector in a reduced-scale rocket engine testing platform with different water spray schemes is analyzed. The standard k - ε turbulent model and Eddy-Dissipation Concept (EDC) model are applied to solve the characteristic of the flow and combustion and the discrete ordinates (DO) model is adopted to simulate the thermal radiation. Model validation shows that the predicted results are in good agreement with the experimental data. In addition, the flow and temperature field of the exhaust gas impinging on the flame deflector under different water injection location, mass flow rate, hydrogen ratio and vertical panel height are numerically investigated. The results reveal that the scheme of centre water spray performs better than other schemes in terms of maximum and area-averaged temperatures. In terms of the flow performance, the case of annulus water spray performs best, followed by centre water spray and bottom water spray worst. With the increase of hydrogen ratio, the reburning of hydrogen results in the amplification of the high-temperature region in the flame deflector. The temperature on the bottom surface decreases gradually but the temperature on the vertical panel increases with the increase of the vertical panel height. [ABSTRACT FROM AUTHOR]

Aim: The purpose of the research was to determine the parameters of the micro- and macro-structure of the streams generated by nozzles of different types, and to identify potential applications of the tested water nozzles, including firefighting and air pollution removal. Introduction: TF6 FCN, TF6 V, NF 15 and CW 50 water nozzles were tested. At supply pressures of 0.2 MPa, 0.4 MPa and 0.6 MPa, the basic parameters of micro- and macrostructure of the streams were measured and determined: flow rate, spray angle, mass distribution of liquid on the surface (spray intensity), non-uniformity of spray density distribution, and average droplet diameters and spray spectrum. A sputter spectrum analyser, using the photoelectric method, was used to determine the microstructural parameters of the stream. Project and methods: Badaniom poddano dysze wodne TF6 FCN, TF6 V, NF 15 oraz CW 50. Przy ciśnieniu zasilania równym 0,2 MPa, 0,4 MPa oraz 0,6 MPa zmierzono i wyznaczono podstawowe parametry mikro- i makrostruktury strumieni: natężenie przepływu, kąt rozpylenia, rozkład masowy cieczy na powierzchni (intensywność zraszania), nierównomierność rozkładu gęstości zraszania oraz średnie średnice kropel i widmo rozpylenia. Do określenia paramentów mikrostrukturalnych strumienia zastosowano analizator widma rozpylenia, wykorzystujący metodę fotoelektryczną. Results: The tested nozzles generated dispersed streams with different parameters. Among the analysed nozzles, the highest degree of dispersion was obtained for the TF 6 FCN sample, whose average Sauter mean diameter (SMD) reached a value of 217.3 μm. In comparison, for the NF15 nozzle this parameter was 945 μm. The spray spectra indicate a high homogeneity of water dispersion in the stream produced by the nozzles TF 6 FCN and CW 50. From the distribution of mass sprinkling density, the CW 50 nozzle shows the greatest uniformity of spraying. At the same time, however, it reports a small amount of water, since the value of the spray density for this product did not exceed 100 g/( m2 · s), while for the NF 15 nozzle it was more than 2,700 g/( m2 · s). The obtained spray angles were close to those declared by the nozzle manufacturer. In the tests of all samples, a slight effect of supply pressure on the values of this parameter was observed. Conclusions: Among other things, the tests made it possible to conclude that in the range of supply pressures of 0.2÷0.6 MPa, the values of disperse angle and spray area of the analysed nozzles were constant or the recorded differences were insignificant. In addition, it was determined that in the case of nozzles with full spray cones, an increase in supply pressure (within the range of declared operating values) has little effect on changing the parameters of the micro- and macro-structure of the stream. The conducted tests showed the potential use of two nozzles (TF6 FCN, CW 50) in low-pressure fog extinguishing systems producing fog with SMD droplet diameters > 200 μm. For the absorption of hazardous substances, it is recommended to use nozzles with a large spray angle and a full spray cone, which, as tests have shown, produce uniform streams with small droplet diameters. Keywords: water nozzles, water spray, spray spectrum, mass spray density, water mist

Nerium is a versatile flowering plant requiring less labor and low input for commercial cultivations. The growers harvest the mature flower buds from late at night to early in the morning hours with the use of a headlight as the flowers exhibit full bloom in the morning. With this background, investigation was done under different conditions of lighting and water spraying in the form of fog in nerium variety 'pink' at Samakuttapatti village, Panamarathupatti Block, Salem district, Tamil Nadu, India. The plant height (268.00 cm) was maximum in the plants exposed with 450-495 nm of blue light for 6 h + water spray (fog) 15 min. for every 1 h. Inflorescence with the highest number of flower buds (9.25) and flower yield (230.80 g plant-1) were recorded in water spray (Fog) 15 min. for every 1 h which highly favored for harvesting between 5.30 A.M. and 7.30 A.M. or preferably in the previous day evening. The same treatment exerted the highest benefit cost ratio (2.83). The Principal Component analysis showed strong association with Percentage of unopened flower buds (POUP), Single flower bud weight (SFBW), Number of flower buds per inflorescence (NFB) and Total number of inflorescence plant-1. [ABSTRACT FROM AUTHOR]

The paper presents a simplified engineering model for the prediction of the rate of heat absorption by heat-up and evaporation of water droplets interacting with fire-induced smoke. The algorithm can be easily implemented in the framework of one-zone or two-zone fire models. The general methodology is based on a decoupled time scale analysis for the heating, evaporation and motion of a single droplet. Such analysis allows to determine the heat absorbed by a droplet during its residence time in the smoke layer. Under the assumption of a monodisperse spray, the injected number of droplets per second is calculated and used to estimate the rate of heat absorption (i.e., cooling) by a full spray. The assessment of the model, for single droplet as well as full spray calculations, has been carried out against results obtained with the Fire Dynamics Simulator (FDS 6.7.0). The results show that the model predicts the rate of heat absorption within 15% for droplet diameters between 0.4 mm and 0.8 mm and a surrounding gas temperature below 150°C. Larger deviations are observed under other conditions. The application of the model to a well-confined and mechanically-ventilated compartment fire (a scenario of relevance to nuclear installations and passive houses) allowed to provide a good estimate of the cooling rate of the water spray system and the subsequent average gas temperature and pressure profile within the room. [ABSTRACT FROM AUTHOR]

The International Convention for the Safety of Life at Sea (SOLAS) recognises five different fire-extinguishing system solutions for ro-ro spaces on ships; manually activated water spray systems (Resolution A.123(V)), automatic sprinkler or deluge water spray systems and automatic nozzle or deluge water mist systems (MSC.1/Circ.1430), high-expansion foam systems and gas fire-extinguishing systems (FSS Code). A review of potential commercially available alternative systems, their expected performance efficiency and water consumption was made. Based on this review, two alternative fire-extinguishing systems were identified: Compressed Air Foam Systems (CAFS) and foam-water sprinkler/spray systems. Fire suppression performance testing of water spray systems according to the Resolution A.123(V) and MSC.1/Circ.1430, a CAFS and a foam-water spray system were conducted. The water spray system per MSC.1/Circ.1430 had superior performance while the system per Resolution A.123(V) and the foam-water spray system limited the fire size to some degrees. The CAFS provided limited fire suppression performance. [ABSTRACT FROM AUTHOR]

Copyright of Journal of South China Agricultural University is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Fire safety is always an important issue in the indoor and built environment. There might be hidden conflicts among different systems such as suppression and smoke control. The effect of water spray on smoke movement in halls with natural venting system is reported in this paper. A series of scale modelling experiments were carried out to study the temperature variation under water spray. A small vent on the opposite side of fire source would intensify smoke stratification and result in a higher smoke temperature. Water spray would weaken the smoke stratification due to the cooling effect on the smoke and the downward drag on the smoke layer. The temperature development of smoke was the result of competition of these two effects on the smoke layer. When the effect of water spray was stronger, the average smoke temperature tended to be lower, and the temperature difference of the ceiling to the smoke layer interface was smaller. When the effect of the opening dominated, the results were reversed. These results would be useful for providing fire safety in indoor and built environment. [ABSTRACT FROM AUTHOR]

The influence of water spray arrangement on temperature reduction performance is significant in temperature and pressure reducing valves (TPRV). A verified vapor-liquid two-phase flow in TPRV was established by Euler-Lagrange flow and droplets evaporation model. The heat and mass transfer processes in droplet evaporation are presented. The influence of nozzles number, spray position, injection direction on internal flow characteristics and temperature reduction performance of TPRV was analyzed. An optimized spray water arrangement was determined via nonlinear fitting model, the great temperature reduction performance was obtained. The results show that the mass flow rate of TPRV inlet and outlet has a non-linear variation with the valve opening. The significant pressure gradient occurs in the valve core and chamber. The upward oblique jet at throat makes the temperature near the spray area low and the temperature at throat downstream high. The range of high Mach numbers increases with the increasing of valve opening. The temperature variation of parallel injection and reverse injection is different with the increasing of the nozzles number. The vortex intensity and range have a stronger influence on temperature reduction performance ability. The temperature reduction performance of optimized TPRV is improved by 0.6 %- 3.98 %. The optimization of water spray arrangement on temperature reduction performance is applicable to various loads. • Euler-Lagrange flow model was established for vapor-liquid two-phase flow in TPRV. • The influence of spray water arrangement on TPRV are nonlinear and obvious. • The vortex intensity and range have strong influence on temperature reduction. • Temperature reduction performance of optimized TPRV is improved by 0.6 %- 3.98 %. [ABSTRACT FROM AUTHOR]

Reduced energy usage is an important concern in vapor compression cooling systems, particularly in hot climates. These systems function poorly in hot weather and consume a lot of electricity. Evaporative condensers use the cooling impact of evaporation to facilitate the process of heat rejection and thereby increase energy efficiency. This work evaluates the impact of employing vortex generators on the performance of an evaporative condenser. The analysis is performed using a validated numerical model, a commercial CFD code. The proposed vortex generators are parallel plates with sinusoidal and zigzag patterns. Dry air enters a channel equipped with four vortex-generating plates and water spray. The incoming dry air cools due to the two-phase heat transfer during air contact with the sprayed water droplets, and the cooled air with the proper humidity level exits the channel. The investigated parameters include longitudinal nozzle position, inlet air flow rate, pitch, and the height of the vortex generator plates in two sinusoidal and zigzag modes and the obtained results are compared with the plain channel model. Greater inlet air velocity resulted in superior output temperatures and pressure drops, yet lower outlet relative humidity and water mass percentage. According to the findings, the air pressure drop and outlet dry temperature are raised by 152 % and 5 %, respectively, when the incoming air velocity is altered from 0.4 to 0.6 m. s−1 (50 % growth), and the nozzle position is moved from X = 1.35 m to X = 1.85 m (37.04 % change) from the channel entrance, while the relative humidity and water mass fraction are decreased by 19 % and 11 %, respectively. Additional research revealed that the vortex flow level is lower when the nozzle is positioned farther away from the plates, and the water spray's impact on lowering the local air temperature in vortex-flowing areas is more substantial when it is positioned closer to the plates. Furthermore, increasing wave height and pitch values of vortex generators result in a more extensive air pressure drop in the channel, and vice versa. This means that, at a fixed pitch, a higher plate wave height raises the amount of vortex flows. According to the findings, sinusoidal vortex plates have better efficiency than the zigzag ones, and in a channel equipped with water spray, the use of vortex plates before the water spray nozzles lowers the dry temperature at the outlet by about one °C compared to that of the plain channel. • Evaporative cooling in a channel with vortex generators is evaluated numerically. • Discrete phase model as Eulerian-Lagrangian two-phase finite volume method is used. • Employed numerical model is validated with experimental results. • Sinusoidal and zigzag plates are considered as vortex generators. • Sinusoidal vortex plates have better efficiency than the zigzag ones. [ABSTRACT FROM AUTHOR]

Efficient aerosol scavenging is crucial for gas purification to reduce environmental pollution in various chemical industries. In nuclear reactor decommissioning, especially for damaged reactors after severe accidents like Fukushima Daiichi, controlling radioactive aerosol generation and dispersion is essential. Radioactive aerosols sizing from 0.1 to 1 μm are expected during containment cleaning and fuel debris retrieval processes. To ensure safe decommissioning and mitigate environmental radioactivity, a containment water spray system is used for aerosol scavenging. However, conventional water spray has low efficiency for these submicron aerosols. Our recent experiments at UTARTS demonstrated that pre-injection of water mist enhances scavenging efficacy by increasing aerosol size and hydrophilicity through aerosol-mist agglomeration prior to spraying. On this basis, in this study, we introduced an innovative method using electrically charged water mist, which significantly facilitates aerosol-mist agglomeration through additional electrostatic coagulation, further improving scavenging efficacy (maximum 35 % in current configurations). The present experimental results attained under various mist conditions and charging configurations provided insights into optimizing the mist charging system. Our developed technology is expected to be useful in radioactive aerosol control during damaged reactor decommissioning and has potential applications in other environmental chemical engineering processes. • An innovative method is proposed to improve aerosol scavenging efficacy. • An electrical charging system is developed to charge submicron water mist. • Charged water mist enhances the aerosol-mist agglomeration prior to spraying. • Aerosol-mist agglomerates are easier to be scavenged by spray. • Charging and electrode configurations are studied to optimize the mist charging system. [ABSTRACT FROM AUTHOR]

This paper presents an evaluation of a system aiming at estimating water depths on a road surface. Using accelerometers, the system records the vibrations of a wheel arch liner due to impacts of water droplets. The system setup, including the location of the accelerometers on a wheel arch and the data acquisition, is described. Tests were performed with a passenger car on various road surfaces and at different vehicle speeds and water depths. Signals recorded by the accelerometers are filtered and processed. The link between the acceleration amplitude, the water depth, and the vehicle speed is consistent with results from previous studies. The effect of the surface texture is less obvious and needs further investigations. A mathematical model has been developed to relate the acceleration amplitude to the water depth. The potential application of the developed system to on-board evaluation of pavement wetness, and consequently the pavement skid resistance, is discussed. Perspectives for driver assistance, or more generally, for autonomous driving to improve traffic safety, are also highlighted.

In order to study the reasonable support technology of weakly cemented soft rock roadway under water spraying condition, the 12307 return airway of Selian No.2 mine was taken as the background. The stress, deformation and plastic zone change characteristics of roadway surrounding under the condition of “anchor belt net and cable beam” support were studied by considering the strength and volume change of weakly cemented sandy mudstone with water spraying time, and the several improvement measures for support plan were proposed. The results of the study show that: under the condition of “anchor belt net and cable beam”, the surrounding rock radial displacement of weakly cemented soft rock roadway will continue to increase exponentially under the influence of water spraying. Finally, its moving distance from roof to floor and two sides will reach 750 mm and 200 mm respectively. After the improved support of “increasing the length of anchor bar, changing metal mesh to reinforced mesh sprayed concrete, and strengthening the support of roadway roof and two sides with anchor ropes”, the surrounding rock maximum radial displacement of weakly cemented soft rock roadway is only 29.0 mm, and the failure plastic zone depth is basically stable at 3.0 m, which well guarantees the safety of the roadway.

Ammonia has a very wide range of applications. Its worldwide production exceeds 230 million tonnes per year. Due to its properties, ammonia causes a serious threat to human life and health when released uncontrolled into the environment. Research carried out in the word shows that this substance may be effectively neutralised by absorption in water. The aim of research described in this paper is to determine the influence of key parameters of the micro- and macrostructure of water streams on the course of the ammonia absorption process. During the studies, different types of water nozzles were used, with similar efficiency and supply pressure, but characterised by different parameters of the micro- and macrostructure of the produced stream. The experiments were divided into two stages. In the first one, the macro- and microparameters of the streams were measured, while in the second one, the changes in ammonia concentration were established during delivering spray jet generation by different nozzles. Among the basic parameters of the macrostructure, the spray angle and liquid distribution in the jet (spray intensity) were determined, while for the microstructure, the droplet size distribution and mean droplet diameters were measured. Ammonia concentration was measured by means of a photoionisation detector (PID). In order to evaluate the absorption efficiency of different water spray jets, the apparent absorption rate (kp) and the half-time of concentration reduction (t½) in the kinetic range were established. The study has confirmed that atomised water jets are an effective method for neutralising ammonia released into the environment. The research has a practical aspect and shows that the structure of atomised water streams influence the course of the absorption process. Increasing the spray angle in a conical stream leads to an improvement in the quality of water atomisation and helps increase ammonia absorption. Moreover, it was also observed that for the absorption of spatial ammonia clouds, use should be made of nozzles generating streams with full spray cones and high uniformity of spray and dispersion. [ABSTRACT FROM AUTHOR]

A novel version of the well-known ablation casting process named as the direct water spraying (DWS) was introduced by applying the process on a simple geometry solidifying casting with a near eutectic A413.0 aluminum alloy. The new solidification term named total cooling rate was found more efficient in justification of the improvement in mechanical properties. A comparison between the DWS processed casting and the conventionally sand-cast counterpart revealed that the secondary dendrite arm spacing could decrease from conventional 68 μm to 32 μm in the DWS specimens. The size of other microstructural features such as eutectic micro-constituents, iron-bearing phases, and shrinkage porosities experiences a significant drop caused by the DWS process. All these were attributed to the higher cooling rate induced by efficient heat extraction. The average ultimate tensile strength and elongation increased from the conventional values of 146 MPa and 2.2% to 160 MPa and 5.2% in DWS, respectively. [ABSTRACT FROM AUTHOR]

Dust deposition on the fin surface of the outdoor heat exchanger seriously affects the operating efficiency of the air source heat pump (ASHP). Considering the operation characteristics of ASHP in summer for cooling and in winter for heating, a dust removal strategy is proposed based on superhydrophobic fin surface (SFS). In summer, the SFS is sprayed to remove dust by collecting the condensate water of air conditioning. In winter, by coupling the dust deposition with the condensation or frosting/defrosting phenomenon on SFS, the self-propelled motions of condensate droplets or the peeling off of the frost layer in defrosting is used to realize the dust removal. The experiment results show that the water spray on SFS has excellent dust removal performance, and the deposited dust is completely removed after 2 sprays. The dust is carried away by the jumping or gliding of the water droplets. The condensation has poor dust removal performance and takes long removal time. After several hours of condensation, the dust removal rate is 89.6 % and 40.0 % on SFS under different dust deposition levels. Due to the peeling off of the frost layer from the SFS at beginning of defrosting, the melting water at the bottom of the frost layer carries the dust away from the fin surface effortlessly. After 2 defrosting cycles, the dust removal rate reaches 99.6 %, while it is 50.1 % on the bare surface. Therefore, the strategy of dust removal by water spray in summer and defrosting in winter is suitable for ASHP. • Dust removal strategy is proposed based on superhydrophobic fin surface. • Strategy considers the operation characteristics of ASHP in summer and winter. • Water spray and defrosting methods show excellent dust removal performance. • Condensation method has poor dust removal performance and takes long removal time. • Dust removal by water spray in summer and defrosting in winter are suitable. [ABSTRACT FROM AUTHOR]

The traditional methods of fighting metal fires are not always safe for firefighters. The sand and salts that are thrown onto the fire to suffocate the flames can lead to splashes of molten metal, putting the firefighters and the surroundings at risk. A novel process is described where magnesium fires are brought under control using a simple two-step process. First, coated cellulose flakes, which contain approx. 30% inorganic salts, are blown onto the fire from a distance of several meters. Due to its low bulk density, the material settles smoothly on the fire and immediately covers the flames for several seconds. Before the hot metal can break through this cover, a fine water spray is applied to the fire. The water spray wets the top layer of the cellulose flakes, which will begin to char from the bottom. The water evaporates from within the cellulose flake layer and withdraws heat. It was observed that no hydrogen is formed and that this technique can safely control fires. It is judged that 90 kg of flakes could safely bring a pile of 75 kg of burning Mg flakes under control. By using a pneumatic conveying unit for the flakes, firefighters can effectively and efficiently cover the flames from a safe distance. This novel method could be recommended to firefighters in industrial magnesium processing plants, as well as local firefighters in the vicinity of such plants. [ABSTRACT FROM AUTHOR]

Objective: To determine the efficacy of cooling gel patch in various clinical indications and comparison of cooling gel patch with water spray and cold sponging in fever and heat exhaustion. Study Design: Comparative cross sectional study. Place and Duration of Study: Garrison Medical Centre Okara Cantt, from Sep to Dec 2018. Methodology: A total of 48 male patients, age ranges from 20-40 years were assessed with different clinical indi-cations of cooling gel patch. Patients with fever, heat exhaustion, headache, muscle cramps and toothache were included in this study and patients with acute illness other than fever were excluded. A control group of 20 individuals was also analyzed against fever and heat exhaustion in which water spray and cold sponging was used. Frequency and percentages of each indication were calculated and chi square test was applied. Results: Total of 48 individuals living in plain terrain with various clinical indications of cooling gel patch were assessed. Cooling Gel Patch was tested on 16 sportsmen with heat exhaustion out of which 2 (12.5%) individual had minimal effect whereas control group of 10 showed good response in 8 (80%) sportsmen with water spray and cold sponging with p-value .000578. Six patients with headache and 4 individuals with toothache reported no reduction in symptoms. Two out of 6 patients with muscle cramps reported mild relief in symptoms. Sixteen patients reported with high grade fever and out of these, 12 (75%) individuals showed no reduction in tempera-ture after 4 hours of application. In 4 (25%) cases fall of 1°F was observed after 2 hrs but no further decrease noted from 4-8 hrs whereas control group of 10 individuals showed very good response with water spray and sponging with p-value

A series of vertical fire suppression experiments on rigid polyurethane (RPU) and flexible polyurethane (FPU) with/without water spray were conducted in a standard chamber. A new video processing method was developed to determine the pyrolysis front position of wind-aided flame. Averaged flame height, carbon monoxide/hydrogen cyanide concentration, view factors, and extinguishing time were determined with operating pressure varying from 0.15 MPa to 0.4 MPa. The experimental study showed that water spray would suppress RPU/FPU fire mainly by fuel surface cooling. Furthermore, the perfect water spray pressure for RPU/FPU fire suppression was 0.3 MPa and the corresponding water application rate was 0.7511 mg/(cm2·s). [ABSTRACT FROM AUTHOR]

Summary: Due to their relatively high thermal effectiveness and ease‐of‐use, direct contact heat exchange units are a favorable choice in heat recovery applications. Today, spray‐based direct heat exchangers are commonly used for a variety of applications, including evaporative cooling and heat recovery. Yet in spite of their versatility, these heat exchangers are not well‐understood, mainly due to their complex liquid/gas interactions, which may deem poorly‐designed systems as undesirable and infeasible. Spray nozzle height and type (hollow and full cone), droplet diameter distribution, inlet air velocity and humidity, and water spray velocity are key parameters required to establish a clear understanding of direct heat exchange performance. To better understand such a multivariable phenomenon, this article offers a comprehensive study of the impact of these key factors. The main purpose of this study is to evaluate the validity of two different methods proposed for evaluating the performance of heat and mass transfer in large‐scale direct contact heat exchangers, namely one‐dimensional and three‐dimensional approaches. The results of the present study show that while the one‐dimensional approach is able to capture the experimental data within 10% of agreement with experiment, the three‐dimensional approach reduces this error to 5%. In addition, this study aims to provide a framework to conduct future parametric studies with the goal of highlighting key performance factors understanding of which are a necessity for improved design of direct contact heat exchangers used in mine waste heat recovery applications. Novelty Statement: To investigate the performance of an industrial‐scale direct (spray) heat exchange system with a vertical configuration for application in mine waste heat recovery, two different models, namely; '1‐D' and '3‐D', are developed.Accuracy of two models in predicting heat transfer is evaluated through comparison with experimental data.A series of parametric studies are conducted to examine the impact of various operating parameters on the performance of heat exchange system. [ABSTRACT FROM AUTHOR]

Copyright of Revista Cientifica de la Facultade de Veterinaria is the property of Universidad del Zulia, Facultad de Ciencias Veterinarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper points out the shortcomings of traditional vehicle-mounted fire extinguishing system in underground coal mines. The advantages and disadvantages of water spray fire extinguishing system are analyzed, and the feasibility of vehicle-mounted water spray fire extinguishing system is discussed. In addition, a vehicle-mounted water spray fire extinguishing system is designed combined with the characteristics of trackless tyred vehicle with the explosion-proof diesel engine. The system is based on the normal pressure dry pipe network, and has the vehicle-mounted water source and air source, as well as the integrated fire source detector and water spray nozzle, thus the fire detection and automatic response is realized. The action mechanism, component configuration and arrangement mode of the control system are discussed. Furthermore, the main parameters of the fire extinguishing system are calculated.

Accumulation of float coal dust (FCD) in underground mines is an explosion hazard that affects all underground coal mine workers. While this hazard is addressed by the application of rock dust, inadequate rock dusting practices can leave miners exposed to an explosion risk. Researchers at the National Institute for Occupational Safety and Health (NIOSH) have focused on developing a water curtain that removes FCD from the airstream, thereby reducing the buildup of FCD in mine airways. In this study, the number and spacing of the active sprays in the water curtain were varied to determine the optimal configuration to obtain peak knockdown efficiency (KE) while minimizing water consumption.

Kitchen fire has been becoming the majority risk to the ancient buildings, as the insufficient firefighting device, the excessive fuel, and the lower fire resistance structure. In this paper, a numerical simulation research was carried to access the effective of water spray in the kitchen fire of ancient buildings. The heat release rate (HRR), smoke temperature and spread process has been obtained, the efficiency of general water spray and kitchen special water spray has been compared, the necessary of the fire alarm device and the water spray have also discussed. The result indicated that the HRR peak is controlled by the water spray and fire detector devices, the activity time of water spray is the majority factor. The flame temperature is approximate to 400 °C without the firefighting device. Though the fire scenario protected by kitchen water spray and fire detector, the flame temperature is 67 °C and the HRR peak is 2.52 kW, which fire has been controlled in 32.7s. The result indicated that it is necessary for the ancient building's kitchen to fix the firefighting devices, and the numerical simulation is useful for the design and selection of firefighting device.

Mechanical stimuli can affect plant growth, development, and defenses. The role of water spray stimulation, as a prevalent mechanical stimulus in the environment, in crop growth and defense cannot be overlooked. In this study, the effects of water spray on tomato plant growth and defense against the chewing herbivore Helicoverpa armigera and necrotrophic fungus Botrytis cinerea were investigated. Suprathreshold water spray stimulus (LS) was found to enhance tomato plant defenses against pests and pathogens while concurrently modifying plant architecture. The results of the phytohormone and chemical metabolite analysis revealed that LS improved the plant defense response via jasmonic acid (JA) signaling. LS significantly elevated the level of a pivotal defensive metabolite, chlorogenic acid, and reduced the emissions of volatile organic compounds (VOCs) from tomato plants, thereby defending against pest and pathogen attacks. The most obvious finding to emerge from this study is that LS enhances tomato plant defenses against biotic stresses, which will pave the way for further work on the application of mechanical stimuli for pest management.

Compared with other types of energy storage systems, compressed air energy storage (CAES) system has the advantages of low cost, long life, and less impact on environmental. Low cycle efficiency limits its development. Enhancement of the heat transfer between air and environment to achieve isothermal compression is an effective method to improve the round trip efficiency of CAES systems. The spray heat exchange method is proposed to achieve isothermal compression. In order to obtain an accurate heat transfer process model, this paper takes into account that the process of water mist spreading from the nozzle to the whole cylinder will lead to local air and water mist heat transfer in the cylinder, and then divides the area in the cylinder into two parts to analyze and calculate the gas state. To verify the rationality of the diffusion model, a high-speed camera is used to observe the spray diffusion process. Meanwhile, the accuracy of the isothermal CAES system model is verified by literature experimental data, and finally the influence of water spray system parameters is obtained. The research results show that to gain fast heat transfer rate, a spray angle is equal to 60°; when the nozzle diameter is reduced from 0.6 mm to 0.4 mm, the compression efficiency of the system increases from 85.53 % to 89.25 %; The orthogonal design method is used to obtain the maximum total efficiency of the system under the given conditions, when the nozzle diameter is 0.6 mm and the water pressure is 0.2 MPa, and its value reaches 88 %. This research provides theoretical support for the in-cylinder spray isothermal CAES system. [ABSTRACT FROM AUTHOR]

Water spray is used for cooling intake air of gas turbine in thermal power plant. It is necessary to reduce the amount of residual droplets by optimizing the spray amount to keep the plant in good condition. In the actual thermal power plants, a phase Doppler anemometry (PDA), which can provide droplet velocity and diameter of spray, is difficult to apply because it requires precision setting. In this study, a new method for determining the residual droplet flow rate using the laser transmittance for the cooling water spray which can be used at thermal power plants is proposed. A laser transmission method system was applied to a scale-down model of an inlet duct at a laboratory in order to confirm the system reliability. The same types of weather louvers, eliminators, and nozzles installed in the actual thermal power plants were used in the experiment. The effects of optical path length, spatial distribution of spray, flow on conditions, etc. to the measurement accuracy were evaluated at the model case experiment in the laboratory. The residual droplet flow rate calculated by the laser transmission method and that of the PDA measurement are compared. The error of the residual droplet flow rate calculated by the proposed method was about 12.8%. The proposed system was applied to an actual thermal power plant. At the thermal power plant, the residual droplet flow rate was reduced to about 35% by the eliminator compared to the case without the eliminator. Since the residual droplet flow rate can be measured by the laser transmission method, it can be used for optimizing the spray amount in actual thermal power plants. Compared to other methods, the proposed method allows the experimental equipment to be also constructed relatively easily. It is easy to install in an actual thermal power plant. The experimental results demonstrate the effectiveness of the present apparatus as a relative evaluation method.

Owing to the increasing worldwide demand for natural gas, the development of a large submerged combustion vaporizer is required. Its burner is equipped with a water spray nozzle to reduce nitrogen oxides, and a practical simulation method is required for the optimal design. The non-adiabatic flamelet approach can predict the combustion emissions and is useful for reducing simulation costs. However, as the number of control variables increases, the database requires larger memory and cannot be dealt with by general computers. In this study, an artificial neural network (ANN) model based on a five-dimensional flamelet database, which includes the effects of heat loss and vapor concentration by sprayed water evaporation, is developed. Furthermore, large eddy simulations (LESs) for turbulent combustion fields with and without water spray are conducted employing flamelet generated manifold (FGM) approach with this ANN model, and the validity is investigated. For comparison, a lab-scale burner equipped with a water spray nozzle is manufactured, and combustion experiments with and without water spray are conducted. The results show that CO, NO, temperature, and reaction rate of progress variable predicted by the present ANN model are in good agreement with those of a five-dimensional flamelet database. In the condition without water spray, the flame behavior predicted by the LES employing the FGM/ANN approach is in good agreement with that employing the conventional FGM approach, while indicating much lower memory, although there appeared some quantitative discrepancies in the temperature against the experiment probably partially because of the insufficiency of the FGM approach for the present complex flame structure. In the condition with water spray, the LES employing the FGM/ANN approach is able to capture the effect of the water spray on the flame behavior in the experiment, such that the water spray decreases the temperature, which causes the decrease in NO but increase in CO.

• A reciprocating spray cooling system is proposed for battery thermal management. • Cooling system contains reciprocating flow channel, heat pipe array, spray nozzle. • The reciprocating spray cooling reduces battery temperature via mist evaporation. • The temperature difference is less than 3.41 °C using reciprocating spray cooling. • Spray frequency, duty cycle, and power allocation influences the heat dissipation. Lithium-ion batteries (LIBs) are critical power sources for portable devices, electric vehicles, power grids, and energy-storage systems. Effective thermal management is mandatory for achieving optimal battery performance. Although the air-cooling method has been investigated extensively owing to its simple structure, convenient maintenance, and low cost, it is insufficient for cooling large-scale battery packs because of its limited air-cooling capacity and unsatisfactory temperature uniformity. Thus, a reciprocating spray cooling system comprising a reciprocating air flow channel, heat pipe array, and spray nozzle is proposed herein for the efficient cooling of 18,650 LIB packs. The effects of the inlet air speed, spray frequency, and spray duty cycle on the cooling performance of the reciprocating mist cooling system and the corresponding optimal operating parameter range are analyzed. Additionally, the competitive mechanism between forced air convection and evaporative cooling is discussed. The results indicate that, compared with the case of natural convection cooling, the temperature increment of the battery pack decreases by 32.1 % under reciprocating mist cooling. Meanwhile, the maximum temperature difference reduces to approximately 3.41 °C with 3C of discharge. The spray frequency minimally affects the overall heat dissipation but induces surface temperature fluctuations in individual batteries. Increasing the spray duration per 10 s in a single spray duty cycle can reduce the average temperature of the battery pack by approximately 2 °C. Additionally, the power-allocation scheme affects the heat dissipation of the system. Decreasing the flow rate of spray cooling water and increasing the inlet air speed promote the evaporation of water mist inside the system, thus further improving heat dissipation. This study provides new insights into the design of air-cooled thermal management systems for battery packs. [ABSTRACT FROM AUTHOR]

During an aircraft taxiing on a water-contaminated runway, the worn tires with shallower grooves will significantly deteriorate the safety of take-off and landing. The hydrodynamics generated by the tire-water-pavement interaction is numerically studied using the coupling method of Smoothed Particle Hydrodynamics and Finite Element Method. By comparing a completely worn tire with a new tire, the effects of tire wear on water spray and water displacement drag are analyzed. With the increasing tire speed and water film depth, the water spray composed of bow wave and side plume increases, and the water displacement drag decomposed of wave- and film-generated components also increases. The effects of tire wear depend on the relative height of tire grooves to the water film depth. For the shallow water film with a depth smaller than the grooves height, the water spray and water displacement drag of new tire is much smaller than those of worn tire, because the groove drainage effect can work very well. While for the deep water film that completely floods the grooves, the water spray and water displacement drag of new tire are similar with those of worn tires, because the groove drainage effect cannot be fully utilized. [ABSTRACT FROM AUTHOR]

Changes in the composition of groups of droplets (sprays) emitted by a drop of water with a diameter of D = 0.42 cm at a velocity of U = 3.3 m/s falling into a crucible with a metal melt (Rose alloy at a temperature of 200°C) are traced by photo and video recording for the first time. In the splash formation mode, groups of small water droplets are successively ejected from the tops of the spikes on the veil around the primary contact area and then from the spikes at the rim of the spreading layer. Further, water droplets fly out vertically and obliquely from the tops of short jets, the streamers. Groups of small droplets are formed when large bubbles burst. After a splash has been formed and its top with suspended gas bubbles has been detached, an emission of compound droplets consisting of a metal core and a water envelope is observed. At the last stage, in addition to water streamers, rarer streamers consisting of a melt alloy are observed and metal droplets fly out from the tops of the streamers. The geometry of the cavity and the layer of boiling water of the spreading drop is traced. [ABSTRACT FROM AUTHOR]

Water spraying is widely being used in many industrial applications because of the benefits it has shown over cooling. This paper presents a numerical investigation to simulate evaporating water spray along a plate of an exchanger. Indeed, we were interested in a horizontal channel whose lower wall is the plate of the exchanger maintained at a heating flow. This plate is exposed to a turbulent airflow in which water droplets were injected. The equations governing the continuous phases (air) and the dispersed phase (water) were developed. These equations were solved using Comsol Multiphysics. A comparison of the simulation results and those of the experiment reveals an acceptable concordance. Therefore, the numerical results present the thermal behavior by studying transversal and longitudinal evolution of temperature. Moreover, the maximum evaporated water flow (mmaxew) and the plate temperature are investigated for several physical parameters of the continuous phase, such as velocity, relative humidity and inlet temperature. The results show that these parameters have significant impact on the cooling of the plate. In addition, mmaxew witnesses a remarkable decrease by increasing relative humidity. However, increasing air velocity and inlet air temperature could improve mmaxew. [ABSTRACT FROM AUTHOR]

Smoldering wildfire in peatlands is one of the largest and most persistent fire phenomena on Earth, which contributes importantly to global carbon emissions. However, very few studies are available on how to extinguish these smoldering wildfires. Herein, we develop an experimental method to explore the effectiveness of the water-based suppression on smoldering peat fire, and the proposed method can also be used to simulate fire suppression by rain. The low-temperature drying process avoids the variation of hydrophobicity of peat soil. The validation shows that the proposed approach can provide a wide range of water-spray intensities with time variation, and two examples of successful suppression of smoldering peat fire and flaming wood crib fire were presented. • The design of small-scale combustion reactor for peat can mimic the smoldering peat fire in the field. • The effectiveness of water-based fire suppression technologies on peat fire are explored in the lab. • The proposed method can evaluate the effect of rain and weather on suppressing the smoldering wildfire.

Hemoroid anorektal bölgenin en çok karşılaşılan, çok sayıda insanda görülen ve insanların yaşam kalitelerini önemli ölçüde etkileyen hastalıklarındandır. Hemoroidal hastalık sorunları, evresine göre değerlendirilen bir yaklaşımla çözümlenmektedir ve hastalığının tedavisinde tıbbi ve cerrahi tedavileri içeren pek çok teknik kullanılmaktadır. Hemoroid tedavisinde kullanılan sıcak su oturma banyosu ve sıcak duş da tıbbi tedaviler içerisinde yer almakta ve hemoroidin hem cerrahi öncesi tedavisinde hem de cerrahi sonrası tedavisinde kullanılmaktadır. Uzun yıllardır kullanılan bu yöntemlerin olumlu etkileri olduğu gibi olumsuz etkileri de görülebilmektedir. Bu sistematik incelemede, hemoroidektomi sonrası sıcak su oturma banyosu veya sıcak duşun kullanımıyla ilgili yapılan araştırmaların gözden geçirilmesi ve çalışmalardan elde edilen verilerin değerlendirilmesi amaçlanmıştır.Yapılan literatür taraması sonucunda hemoroid tedavisi sonrası sıcak su oturma banyosu ve sıcak duş ile ilgili yeterince kaynağa ulaşılamamıştır. Ulaşılan kaynaklarda sıcak su uygulamasının girişimsel hemoroidektomi sonrası ağrı üzerine olumlu etkileri olduğu bildirilmiştir.