Accession Number : ADA489402


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


Descriptive Note : Interim rept. 30 Nov 2006-14 Sep 2007


Corporate Author : AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH PROPULSION DIRECTORATE


Personal Author(s) : Elston, Levi J ; Yerkes, Kirk L ; Thomas, Scott K ; McQuillen, John


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a489402.pdf


Report Date : Sep 2008


Pagination or Media Count : 261


Abstract : The objective of this thesis was to investigate the cooling performance of a 16-nozzle spray array, using FC-72 as the working fluid, in variable gravity conditions with additional emphasis on fluid management and flow stability. 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 by 25.4 [mm] area on a thick film resistive heater used to simulate electronic components. Data was taken and reduced as a result of flight tests conducted over the course of two flight weeks (each week consisting of four flights, each flight consisting of 40 to 60 parabolas). The flight tests were conducted in order to examine gravity effects on spray cooling performance and to evaluate a novel liquid-vapor separator design. The mass flow rate through the 16-nozzle spray array ranged from 13.1 m 21.3 [g/s] for the spray cooling analysis and 14m 35 [g/s] for the separator evaluation. The heat flux at the thick film resistor ranged from 2.9 q25 [W/cm2], the subcooling of the working fluid.


Descriptors :   *COOLING , *GRAVITY , *ELECTRONIC EQUIPMENT , *HEAT TRANSFER , FLOW RATE , TEMPERATURE CONTROL , CALIBRATION , QUALITATIVE ANALYSIS , HEAT FLUX , FLUID CONTROL , MASS FLOW , THESES , ARRAYS , SEPARATORS , FLIGHT TESTING


Subject Categories : Air Condition, Heating, Lighting & Ventilating
      Thermodynamics


Distribution Statement : APPROVED FOR PUBLIC RELEASE