scholarly journals A thermal parametric study of non-evaporative spray cooling process

2018 ◽  
Vol 240 ◽  
pp. 01030
Author(s):  
Abdessalam Otmani ◽  
Hocine Mzad ◽  
Kamel Bey
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Spray Cooling ◽  
Comsol Multiphysics ◽  
Cooling Process ◽  
Height Range ◽  
Hydrodynamic Parameters ◽  
Present Simulation ◽  
Very High ◽  
Water Spray Cooling

Ordinary water spray cooling is connected with very high temperatures where heat transfer during evaporation plays a key role. However, during cooling without phase change, the behaviour of the spray cooling parameters is rarely considered. The purpose of this paper is to study the influence of spray hydrodynamic parameters on heat transfer without liquid phase change during the cooling of an aluminium 3003-H18 plate at a temperature of 92 °C. First of all, the flow rate was varied from 0.497 up to 1 l/min. Then, the inlet pressure varied from 0.7 to 2.1 bars. The influence of nozzle-to-target distance is also tested since the simulations were carried out in a wide height range, from 100 mm to 505 mm. The present simulation was achieved using the version 5.2 of COMSOL Multiphysics code.

scholarly journals Parametric study of non-evaporative spray cooling on aluminum plate: Simulation and analysis

2019 ◽  
Vol 23 (Suppl. 4) ◽  
pp. 1393-1402
Author(s):  
Abdessalam Otmani ◽  
Hocine Mzad
Keyword(s):  
Flow Rate ◽  
Fluid Pressure ◽  
Spray Cooling ◽  
Aluminum Plate ◽  
Comsol Multiphysics ◽  
Cooling Process ◽  
Hot Plate ◽  
Height Range ◽  
Nozzle Height ◽  
Spray Distribution

As the behavior of the spray cooling parameters, during cooling without phase change, is rarely considered and there are only little investigations on that matter, this work is focused on the influence of the parameters involved in water spraying cooling process of an aluminum plate at a temperature of 92?C. A detailed study of the effects of mass-flow rate, fluid pressure and the nozzle height above the hot plate was achieved using the version 5.2 of the COMSOL Multiphysics code. First of all, the flow rate was varied from 0.497 up to 1 L/min. Then, the inlet pressure varied from 0.7 to 2.1 bars. The influence of nozzle-to-target distance is also tested since the simulations were carried out in a wide height range (100 to 505 mm). The effect of the studied parameters on the temperature, total internal energy, convective heat flux, Reynolds number, spray distribution and velocity was investigated.

Simulation of Laser-Induced Thermoelastic Behavior in Metal Plates

2013 ◽  
Vol 748 ◽  
pp. 327-330
Author(s):  
Yu Xin Sun ◽  
Jing Xin Liu ◽  
Qi Rong Sun
Keyword(s):  
Heat Transfer ◽  
Laser Pulse ◽  
Phase Change ◽  
Stress Fields ◽  
Comsol Multiphysics ◽  
Thickness Direction ◽  
Commercial Software ◽  
Metal Plates

In this paper, the thermoelastic behavior of Al plate induced by laser pulse is simulated using the commercial software COMSOL Multiphysics. In the simulation, the heat transfer in combination with phase change is considered. The variation of the temperature and stress fields along the thickness direction is obtained and analyzed.

Heat Transfer Associated With Air-Water Spray Cooling of Forgings From High Temperatures

2001 ◽  
Author(s):  
J. Ward ◽  
M. de Oliveira ◽  
D. R. Garwood ◽  
R. A. Wallis
Keyword(s):  
Heat Transfer ◽  
Water Flow ◽  
Gas Turbines ◽  
Spray Cooling ◽  
Solution Temperature ◽  
Air Cooling ◽  
Water Spray ◽  
Transfer Rates ◽  
Wide Range ◽  
Water Spray Cooling

Abstract The desired mechanical properties of the nickel-based or titanium forgings used in gas turbines for aircraft and power generation applications can be controlled by varying the rate of cooling from the so-called solution temperature during an initial heat treatment process. The use of dilute air-water spray cooling of these forgings is a technique which can provide heat transfer rates lying between those associated with conventional oil quenching or convective air-cooling. Air assisted atomisation can result in fine sprays over a wide range of water flow rates and it has a further advantage in that the air “sweeps” the surface and hence helps to prevent the build up of deleterious vapour films at high surface temperatures. The paper presents experimental data for the heat transfer rates associated with the use of these sprays to cool surfaces from temperatures of approximately 800°C. Many forgings contain surface recesses, which can lead to build up or “pooling” of the water so that the effect of variations in surface geometry is also reported. Periodic interruption of the water flow is a technique which can be employed to provide additional control of the heat transfer rate, particularly at temperatures below 500°C so that data is also presented for pulsed sprays.

scholarly journals Wetting layer evolution and interfacial heat transfer in water-air spray cooling process of hot metallic surface

2021 ◽  
pp. 318-318
Author(s):  
Lidan Ning ◽  
Liping Zou ◽  
Zhichao Li ◽  
Huiping Li
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Nucleate Boiling ◽  
Spray Cooling ◽  
Film Boiling ◽  
Metallic Surface ◽  
Interfacial Heat Transfer Coefficient ◽  
Interfacial Heat Transfer ◽  
Cooling Process ◽  
Inverse Heat Transfer

Spray cooling experiments on the hot metallic surfaces with different initial temperatures were performed. This paper adopts a self-developing program which is based on the inverse heat transfer algorithm to solve the interfacial heat transfer coefficient and heat flux. The temperature-dependent interfacial heat transfer mechanism of water-air spray cooling is explored according to the wetting layer evolution taken by a high-speed camera and the surface cooling curves attained by the inverse heat transfer algorithm. Film boiling, transition boiling, and nucleate boiling stages can be noticed during spray cooling process of hot metallic surface. When the cooled surface?s temperature drops to approximately 369?C - 424?C; the cooling process transfers into the transition boiling stage from the film boiling stage. The wetting regime begins to appear on the cooled surface, the interfacial heat transfer coefficient and heat flux begin to increase significantly. When the cooled surface?s temperature drops to approximately 217?C - 280?C, the cooling process transfers into the nucleate boiling stage. The cooled surface was covered by a liquid film, and the heat flux begins to decrease significantly.

Experimental Investigation on Heat Transfer of Water Spray Cooling by Addition of n-Butanol

2020 ◽  
Author(s):  
Chang Cai ◽  
Hong Liu ◽  
Han Chen ◽  
Chuanqi Zhao ◽  
Jiuliang Gao ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Surface Temperature ◽  
Heat Dissipation ◽  
Absolute Error ◽  
Spray Cooling ◽  
High Heat Flux ◽  
Water Mixture ◽  
Water Spray ◽  
Maximum Absolute Error ◽  
Water Spray Cooling

Abstract Heat transfer characteristics of water spray cooling with n-butanol additive were experimentally studied in this paper. The results indicated that adding n-butanol can effectively enhance the heat dissipation and control the surface temperature. The optimal concentration of n-butanol corresponding to the best heat transfer performance is 0.5 vol%. The experimental Nusselt numbers also agree well with a previous correlation with Weber, Prandtl, Jacob and Reynolds numbers, evidenced by a maximum absolute error of 6.34%. The measurement also showed that the decrease of surface tension and contact angle of the n-butanol-water mixture is the main mechanism to enhance the spray cooling heat transfer, while other physical properties also play an important role. The surface temperature non-uniformity in the radial direction is more apparent at a high heat flux while the addition of different contents of n-butanol has a negligible effect.

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