Accession Number : ADA284090


Title :   The Effects of Channel Curvature and Protrusion Height on Nucleate Boiling and the Critical Heat Flux of a Simulated Electronic Chip


Descriptive Note : Final rept. 1 Aug 1989-1 May 1994


Corporate Author : WRIGHT LAB WRIGHT-PATTERSON AFB OH


Personal Author(s) : Leland, John E


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a284090.pdf


Report Date : May 1994


Pagination or Media Count : 276


Abstract : The quest for higher power yet smaller electronics has given rise to the need for very effective cooling of these electronics. Because one of the foremost problems in electronics cooling is achieving high heat flux cooling within small packages while expending minimal pumping power, one focus of this study was to investigate the effects of channel curvature on the CHF. Experimental data were obtained for flow rates of 1-7 m/s, subcoolings of 5-35 deg C, and radii of curvature of 25.4 and 50.8 mm. A correlation was obtained for these data which provided an excellent fit. One condition that has been ignored in the literature is the effect of the simulated heat source not being flush with the flow channel wall. In manufacturing an electronics cooling device, it will be very difficult to maintain the flush chip condition because of the dissimilar materials involved and the numerous thermal cyclings that the device will go through. Experiments showed a significant effect on CHF of the simulated heat source not being flush. A series of data was obtained for flow velocities of 1-4 m/s and subcoolings of 20-35 deg C. CHF data were obtained for a surface recessed 0.127 mm, a flush surface, and surfaces protruded 0.229, 0. 457, and 0.635 mm into the flow stream.


Descriptors :   *CHIPS(ELECTRONICS) , *HEAT FLUX , *NUCLEATE BOILING , VELOCITY , HEAT TRANSFER , EXPERIMENTAL DATA , CORRELATION , FLOW RATE , COOLANTS , IMMERSION , THERMOELECTRIC COOLING , FAILURE(ELECTRONICS) , STREAMS , THERMAL CYCLING TESTS , POWER , WALLS , CURVATURE , MANUFACTURING , DIELECTRICS , SURFACE ROUGHNESS


Subject Categories : Electrical and Electronic Equipment
      Thermodynamics


Distribution Statement : APPROVED FOR PUBLIC RELEASE