Variable-Gravity Effects on a Single-Phase Partially-Confined Spray Cooling System

Yerkes, Kirk L.; Michalak, Travis E.; Baysinger, Kerri M.; Puterbaugh, Rebekah L.; Thomas, Scott K.; McQuillen, John

doi:10.2514/6.2006-596

Cited by 5 publications

(1 citation statement)

References 4 publications

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“…3. The selected spray nozzle is a full cone Spraying Systems 1/8-G Full Jet nozzle since it was determined by Yerkes et al 20 to give the optimal performance out of several nozzles tested for spray cooling applications. It was also this reason Krietzer 2 incorporated its spray profile in the original MC model.…”

Section: A Spray Apparatusmentioning

confidence: 99%

Droplet impact time histories for a range of Weber numbers and liquid film thicknesses for spray cooling application

Hillen

Taylor

Menchini

et al. 2013

43rd Fluid Dynamics Conference

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Spray cooling is a topic of current interest for its ability to uniformly remove high levels of waste heat for densely packed microelectronics. A Monte-Carlo (MC) spray cooling simulation model is under development that is based on empirical data to be a cost effective design tool that will predict accurate heat fluxes based on nozzle conditions and heater geometry. This work reports spray and single drop experiments with the goal of computing the volume beneath a drop impact cavity (sub-cavity volume) created by a single impinging droplet on an initial liquid layer. A relevant test plan for the single drop experiments in terms of We and Re numbers was created through utilization of Phase Doppler Anemometry to characterize a water spray generated by a nozzle of interest for varying flow conditions. Liquid thickness profiles of the sub-cavity formed by a single impinging drop onto a range of initial liquid film thicknesses were measured versus time via a non-contact optical thickness sensor. Time dependent sub-cavity volumes were computed by integrating these sub-cavity liquid film thickness profiles measured radially outward from the impact centerline. It is found that higher We and lower h 0 * result in a more radially uniform sub-cavity surface contour versus time, except for regions near the outer bottom cavity radius, where the liquid film was thinner. The sub-cavity volume was found to be nearly constant for a majority of the cavity lifetime and increased with We and h 0 * . These results will be incorporated in future work into the MC model to improve its predictive capability. Nomenclatured = Drop diameter Greek Letters D = Arithmetic mean droplet diameter ρ = Density D 32 = Sauter mean droplet diameter η = Index of refraction Fr = Froude number = μ = Dynamic viscosity h = Liquid film thickness σ = Surface tension R = Radial location τ = Dimensionless time (t•V axial /d) Re = Reynolds number = Superscripts T = Temperature * = Dimensionless parameter t = Time Subscripts V = Arithmetic mean velocity 0 = Initial condition Vol = Sub-cavity volume axial = Axial velocity component We = Weber number = c = Cavity z = Axial standoff distance from the nozzle tip r = Radial velocity component s = Spray

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Section: A Spray Apparatusmentioning

confidence: 99%