Cooling Performance of a Partially-Confined FC-72 Spray: The Effect of Variable Gravity (Postprint)
Abstract
This paper discusses the effects of a variable-gravity environment on the performance of a subcooled partially-confined spray. An experiment was flown on the NASA KC-135, providing various gravity levels (- 0.16, 0.35, 1.0, and 1.8 g). The experiment consists of a nozzle spraying on a Thick Film Resistor (TFR) heater which is mounted on an insulating glass pedestal. The working fluid is FC-n. Non-dimensional heat input varied over the range 35 < (1-f) GDelta < 190, with a heat flux of 20 < (l-f)q" < 70 W/cm2. The non-dimensional grouping (Frl/2Ga)l/2, a ratio of inertia and acceleration forces to viscous forces, varied over the range 35 < (Fr1/2Ga)l/2 < 70. Subcooling temperature ranged from 24 deg C < Tsc < 30 deg C. For this data, from one flight week of three flights, DeltaT = Ts-Tsat is found to decrease with decreasing values of (Fr1/2Ga)l/2. It appears that higher values for subcooling may enhance this acceleration effect. Changing the flow rate may affect how much the acceleration level affects the 2-phase heat transfer coefficient (h2-p), with the higher flow rate showing less of a change in h2-p as the acceleration level changes.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2007
- Accession Number
- ADA468416
Entities
People
- Kirk L. Yerkes
- Rebekah Puterbaugh
- Travis E. Michalak
Organizations
- Air Force Research Laboratory