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):

Report Date:

1994-05-01

Pagination or Media Count:

276.0

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 ms, 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 ms 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.

Subject Categories:

  • Electrical and Electronic Equipment
  • Thermodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE