Large Area Spray Cooling

Lin, Lanchao; Ponnappan, Rengasamy; Yerkes, Kirk L.; Hager, Brian

doi:10.2514/6.2004-1340

Cited by 32 publications

(12 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The system level critical heat flux for the large surface area was over 50 W/cm 2 for this spray condition at 275.7 kPa with FC-72™. This number compares well with published data for large area systems containing more nozzles per spray area [9]. As mentioned previously, the heat flux is dependent on the spray conditions in addition to the available flow rate determined by the number of nozzles which was kept to a minimum due to cost and complexity for this design.…”

Section: Spray Cooling System Performancementioning

confidence: 63%

“…A spray cooling system was selected for this application since spray cooling takes advantage of an atomized spray impingement on the heated surface as well as the potential for heat transfer from the latent heat of vaporization resulting from a phase change of the working fluid from liquid to vapor. Spray cooling systems with phase change have the capability of achieving heat fluxes upwards of 100 W/cm 2 for Fluorinerts and 1000 W/cm 2 for water [9,10].…”

Section: Thermal Management Systemmentioning

confidence: 99%

See 1 more Smart Citation

Double sided spray cooled bi-directional power conversion module

Rowden

Trowler

Balda

2009

2009 IEEE Electric Ship Technologies Symposium

View full text Add to dashboard Cite

In this work, a power conversion module (PCM) was packaged and integrated with a double-sided spray cooling system developed to demonstrate vertical thermal management system integration. The parallel design of the power electronics and thermal management system provide the capability for high power density. The spray cooling system designed provides capability for relatively large areas with heat fluxes above 50 W/cm 2 using a dielectric fluid like FC72™.

show abstract

Section: Spray Cooling System Performancementioning

confidence: 63%

Section: Thermal Management Systemmentioning

confidence: 99%

Double sided spray cooled bi-directional power conversion module

Rowden

Trowler

Balda

2009

2009 IEEE Electric Ship Technologies Symposium

View full text Add to dashboard Cite

show abstract

“…Lin and Ponnappan [21] investigated the critical heat flux of various fluids including FC-72, FC-87, methanol, and water. Lin et al [22,23] examined orientation effects (heated surface both vertical and horizontal with the spray facing upward) of a 48-nozzle array using in which a 5% increase in critical heat flux, in the horizontal surface case, over the vertical heated surface was demonstrated. Lin et al [24] explored the spray cooling performance of a binary fluid (50% methanol and 50% water) to reduce the freezing point of water to −40 • C while maintaining convective performance near that of water.…”

Section: List Of Tablesmentioning

confidence: 99%

Effect of Variable Gravity on the Cooling Performance of a 16-Nozzle Spray Array

Elston

Yerkes

Thomas

et al. 2009

47th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

Self Cite

View full text Add to dashboard Cite

It was found that the cooling performance was enhanced in micro-gravity over terrestrial and elevated gravity. In addition, a sudden degradation in performance was found at high mass flow rates in micro-gravity, possibly due to liquid buildup on the surface between the nozzle impact zones. A high degree of subcooling was found to be beneficial, but the dissolved air content had little effect on the heat transfer performance either in micro-gravity or elevated gravity. Also, an improved liquid-vapor separator concept was implemented to enable flow stability during the micro-gravity portions of the flight. Multiple liquid-vapor separator concepts were tested during micro-gravity flights until a final design was settled on. The final separator design went through more rigorous evaluation to compare performance at multiple fill levels, each with a higher percentage of vapor space within the reservoir. It was found that, using the final reservoir design, stable flow operation was achieved in micro-gravity for mass flow ratesṁ = 14, 17.5 and 21 [g/s].iv

show abstract

“…Lin and Ponnappan [21] investigated CHF of various fluids including FC-72, FC-87, methanol, and water. Lin and Ponnappan [22] and Lin et al [23] examined orientation effects (heated surfaces, both vertical and horizontal, with the spray facing upward) of a 48-nozzle array using FC-72, in which a 5% increase in CHF, in the horizontal-surface case, over the vertical heated surface was demonstrated. Lin et al [24] explored the spray cooling performance of a binary fluid (50% methanol and 50% water) to reduce the freezing point of water to 40 C while maintaining convective performance near that of water.…”

Section: Introductionmentioning

confidence: 97%

Cooling Performance of a 16-Nozzle Array in Variable Gravity

Elston

Yerkes

Thomas

et al. 2009

Journal of Thermophysics and Heat Transfer

View full text Add to dashboard Cite

The objective of this paper was to investigate the cooling performance of a 16-nozzle spray array using FC-72 as the working fluid in variable-gravity conditions. A flight-test experiment was modified to accommodate a 16-nozzle spray array, which was then tested in the parabolic flight trajectory environment of NASA's C-9 reduced-gravity aircraft. The 16-nozzle array was designed to cool a 25:4 25:4 mm 2 area on a thick-film resistive heater used to simulate an electronic component. Flight tests were conducted over the course of two flight weeks (each week consisting of four flights and each flight consisting of 40 to 60 parabolas). The mass flow rate through the 16-nozzle spray array ranged from 13:1 _ m 21:3 g=s. The heat flux at the thick-film resistor ranged from 2:9 q 00 25 W=cm 2 , the subcooling of the working fluid ranged from 1:6 T sc 18:4 C, the saturation temperature ranged from 37:4 T sat 47:2 C, and the absorbed air content in the working fluid was C 10:1, 14.3 and 16.8% by volume. The spray chamber pressure ranged from 42 P 78 kPa and the acceleration ranged from 0:02 a 2:02 g. Two-phase cooling was emphasized, but some single-phase data were also collected. A one-dimensional model was used to predict the heater surface temperature from the heat input and mean heater base temperature. It was found that the cooling performance was enhanced in microgravity over terrestrial and elevated gravity. In addition, a sudden degradation in performance was found at high mass flow rates in microgravity, possibly due to liquid buildup on the surface between the nozzle impact zones. A high degree of subcooling was found to be beneficial, but the dissolved air content had little effect on the heat transfer performance in either microgravity or elevated gravity. Nomenclature A = area, m 2 a = acceleration, m=s 2 C = percent of dissolved air content by volume, V air =V FC-72 V air 100 D = mean droplet diameter, m Fr = Froude number, v 2 =aD f = fraction of heat lost down the pedestal Ga = Galileo number, aD 3 2 = 2 G = nondimensional heat input, Q=2k r WT sat T 1 k = thermal conductivity, W=m K L = heater layer thickness, m _ m = mass flow rate, kg=s P = chamber pressure, kPa Q = heat rate, W q 00 = heat flux, W=m 2 T = temperature, K T = average temperature, K V = volume, m 3 v = droplet velocity, m=s W = heater width, m We = Weber number, v 2 D= T = temperature difference, K = viscosity, Pa s = density, kg=m 3 = surface tension, N=m, or standard deviation = nondimensional temperature, T T 1;surf =T sat T 1;surf Subscripts c = heater ceramic layer (substrate) g = heater glass layer (cover plate) in = nozzle inlet int = interface between phenolic base and bottom of heater r = heater resistive layer sat = saturated condition sc = subcooling surf = heater surface exposed to spray 1 = freestream condition

show abstract

Large Area Spray Cooling

Cited by 32 publications

References 3 publications

Double sided spray cooled bi-directional power conversion module

Double sided spray cooled bi-directional power conversion module

Effect of Variable Gravity on the Cooling Performance of a 16-Nozzle Spray Array

Cooling Performance of a 16-Nozzle Array in Variable Gravity

Contact Info

Product

Resources

About