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Experimental Estimate of the Continuous One-Dimensional Kernel Function in a Rectangular Duct with Forced Convection
Journal of Heat Transfer (2006)
  • Jinny Rhee, San Jose State University
  • Robert J. Moffat, Stanford University

The continuous, one-dimensional kernel function in a rectangular duct subject to forced convection with air was experimentally estimated using liquid crystal thermography techniques. Analytical relationships between the kernel function for internal flow and the temperature distribution resulting from a known heat flux distribution were manipulated to accomplish this objective. The kernel function in the hydrodynamically fully developed region was found to be proportional to the streamwise temperature gradient resulting from a constant heat flux surface. In the hydrodynamic entry region of the rectangular duct, a model for the kernel function was proposed and used in its experimental determination. The kernel functions obtained by the present work were shown to be capable of predicting the highly nonuniform surface temperature rise above the inlet temperature resulting from an arbitrary heat flux distribution to within the experimental uncertainty. This is better than the prediction obtained using the analytically derived kernel function for turbulent flow between parallel plates, and the prediction obtained using the conventional heat transfer coefficient for constant heat flux boundary conditions. The latter prediction fails to capture both the quantitative and qualitative nature of the problem. The results of this work are relevant to applications involving the thermal management of nonuniform temperature surfaces subject to internal convection with air, such as board-level electronics cooling. Reynolds numbers in the turbulent and transition range were examined. [ABSTRACT FROM AUTHOR] Copyright of Journal of Heat Transfer is the property of American Society of Mechanical Engineers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

  • kernel function,
  • rectangular duct,
  • forced convection
Publication Date
August, 2006
Publisher Statement
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Citation Information
Jinny Rhee and Robert J. Moffat. "Experimental Estimate of the Continuous One-Dimensional Kernel Function in a Rectangular Duct with Forced Convection" Journal of Heat Transfer Vol. 128 Iss. 8 (2006)
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