Experimental investigation on the characteristics of film thickness and temperature on the heated surface during spray cooling

2022 ◽  
Vol 51 ◽  
pp. 101871
Author(s):  
Dongyun Ma ◽  
Shinan Chang ◽  
Ke Wu ◽  
Chen Yang
Keyword(s):  
Experimental Investigation ◽  
Film Thickness ◽  
Heated Surface ◽  
Spray Cooling

Correlation of Heat Transfer Data to Film Thickness Data of the Thin Film Found in Spray Cooling

2004 ◽  
Author(s):  
Adam G. Pautsch ◽  
Timothy A. Shedd
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Film Thickness ◽  
Heated Surface ◽  
Spray Cooling ◽  
Heat Fluxes ◽  
Experimental Measurements ◽  
Transfer Coefficients ◽  
Two Phase ◽  
Heat Transfer Coefficients

As electronic circuit design and packaging technology progresses, the density and power levels of electronic components is increasing at a nearly exponential rate. The higher heat loads dissipated by these devices are nearing the limits of traditional cooling techniques. One method capable of removing heat fluxes as high as 100 W/cm2 is spray cooling. This process involves the impingement of liquid droplets onto a heated surface, forming a thin two-phase film. In order to create reliable models of the heat transfer during spray cooling, the behavior of the film must be understood. This paper presents an investigation into the behavior of the thin film found in spray cooling. A study was performed to relate experimental measurements of the heat transfer coefficients to experimental measurements of film thickness as they vary spatially over a die surface. Both a single nozzle and a multi-nozzle array were investigated. Measured heat transfer coefficients ranged from 0.2 to 1.2 W/m2K and film thicknesses ranged from 90 to 300 μm.

Numerical Simulation of Heat Transfer Mechanisms in Spray Cooling

2010 ◽  
Author(s):  
Eelco Gehring ◽  
Mario F. Trujillo
Keyword(s):  
Heat Transfer ◽  
Heated Surface ◽  
Spray Cooling ◽  
Impingement Zone ◽  
Ongoing Work ◽  
Efficient Suppression ◽  
A Cell ◽  
Cooling Behavior ◽  
Free Surface Capturing ◽  
The Impact

A primary mechanism of heat transfer in spray cooling is the impingement of numerous droplets onto a heated surface. This mechanism is isolated in the present and ongoing work by numerically simulating the impact of a single train of FC-72 droplets employing an implicit free surface capturing methodology. The droplet frequency and velocity ranges from 2000–4000 Hz, and 0.5–2 m/s, respectively, with a fixed drop size of 239 μm. This gives a corresponding Weber and Reynolds range of 10–170 and 330–1300, respectively. Results show that the impingement zone is largely free of phase change effects due to the efficient suppression of the local temperature field well below the saturated value. Due in part to the relatively high value of the Prandtl number and the compression of the boundary layer from the impingement flow, a cell size on the order of 1 μm is necessary to adequately capture the heat transfer dynamics. It is shown that the cooling behavior increases in relation to increasing frequency and impact velocity, but is most sensitive to velocity. In fact, for sufficiently low velocities the calculations show that the momentum imparted on the film is insufficient to maintain a near stationary liquid crown. The consequence is a noticeable penalty on the cooling behavior.

Experimental investigation of parameters effect on heat transfer of spray cooling

2010 ◽  
Vol 46 (8-9) ◽  
pp. 911-921 ◽  
Author(s):  
Wen-Long Cheng ◽  
Qi-Nie Liu ◽  
Rui Zhao ◽  
Han-lin Fan
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Spray Cooling

Experimental Investigation of Submerged Impinging Jet Using Cu-Water Nanofluid

2010 ◽  
Author(s):  
Qiang Li ◽  
Yimin Xuan ◽  
Feng Yu ◽  
Junjie Tan
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Volume Fraction ◽  
Cooling System ◽  
Heated Surface ◽  
Particle Volume Fraction ◽  
Jet Impingement ◽  
Particle Volume ◽  
Impingement Cooling ◽  
System Pressure

An experimental investigation was performed to study the heat transfer and flow features of Cu-water nanofluids (Cu particles with 26 nm diameter) in a submerged jet impingement cooling system. Three particular nozzle-to-heated surface distances (2, 4 and 6 mm) and four particle volume fractions (1.5%, 2.0%, 2.5% and 3.0%) are involved in the experiment. The experimental results reveal that the suspended nanoparticles increase the heat transfer performance of the base liquid in the jet impingement cooling system. Within the range of experimental parameters considered, it has been found that highest surface heat transfer coefficients can be achieved using a nozzle-to-surface distance of 4 mm and the nanofluid with 3.0% particle volume fraction. In addition, the experiments show that the system pressure drop of the dilute nanofluids is almost equal to that of water under the same entrance velocity.

Experimental investigation of large area spray cooling with compact chamber in the non-boiling regime

2015 ◽  
Vol 80 ◽  
pp. 160-167 ◽  
Author(s):  
Wen-Long Cheng ◽  
Wei-Wei Zhang ◽  
Li-Jia Jiang ◽  
Shuang-Long Yang ◽  
Lei Hu ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Spray Cooling ◽  
Large Area ◽  
Boiling Regime

Spray Cooling of Small-Pitched, Straight-Finned, Copper Heat Sinks

2005 ◽  
Author(s):  
Johnathan S. Coursey ◽  
Jungho Kim ◽  
Kenneth T. Kiger
Keyword(s):  
Single Phase ◽  
Flat Surface ◽  
Heated Surface ◽  
Spray Cooling ◽  
Heat Fluxes ◽  
Heat Sinks ◽  
Lower Wall ◽  
Projected Area ◽  
Two Phase ◽  
Flow Flux

Spraying a dielectric liquid such as PF-5060 (95% pure FC-72) has been shown to be an effective method of cooling high power electronics. Recent studies have illustrated the potential enhancement of spray cooling by the addition of extended structures, particularly straight fins, to the heated surface. In the current work, these studies are extended to finer fin widths and pitches and longer fin lengths. Four such heat sinks were EDM wire machined. These 1.41 × 1.41 cm2 heat sinks featured a fin pitch of 0.86 mm; a fin width of 0.5 mm; and fin lengths of 0.5 mm, 1 mm, 3 mm, and 5 mm, which substantially increase the total area, allowing more residence time for the incoming liquid to be heated by the wall. The four enhanced surfaces and a flat surface with the same projected area were sprayed with a full cone nozzle using PF-5060 at 96 mL/min, 24°C, and 3.65 atm (38.5 psig). In all cases, the enhanced surfaces improved thermal performance. Longer fins were found to outperform shorter ones in the single-phase regime. Adding fins also resulted in two-phase effects and higher heat transfer at lower wall temperatures than the flat surface. Finally, the two-phase regime appeared to be marked by a balance between added area, changing flow flux, channeling, and added conduction resistance. Although critical heat flux (CHF) was not reached for the finned surfaces, fin lengths between 1–3 mm appeared to be optimum for heat fluxes as high as 131 W/cm2 and the range of conditions studied.

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