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Estimation of surface temperature, surface heat flux and heat transfer coefficient in the platform of inverse heat conduction problems

Posted on:2014-07-20Degree:M.SType:Thesis
University:The University of Texas at San AntonioCandidate:Soujoudi, RaminFull Text:PDF
GTID:2452390005488309Subject:Engineering
Abstract/Summary:
In many dynamic heat transfer problems, the surface temperature profile of a surface heat flux can be determined from transient temperature measurements in one or more interior and exterior locations of heated solid body. This analysis is referred to as an inverse heat conduction problem. The objective of this study is to develop a method by which a stable prediction of heat transfer on an inaccessible boundary can be obtained without altering the thermal boundary condition that would have existed where thermal sensors were not present. In this work, the technique of Method of Lines (MOL) is applied to a one dimensional transient heat conduction problem for a large slab and a long cylinder to determine the unknown surface temperature and surface heat flux for both constant and triangular heat waves. The results indicate that the computation time variant surface temperature converges rapidly after short times( τ>0.1 ).;The second part of this study investigates heat transfer from the surface of a hot solid that is immersed rapidly in cooler fluid. It is demonstrated that the approximate temperature distributions for two bodies consisting of a large slab and a long cylinder are equivalent to an analytical solution using first term series solutions. It is also shown that the series solutions converge rapidly for periods of time, and for τ > 0.2. Only the first term of the series needs to be retained for 2% accuracy.;In the final stage, this technique was tested with experimental data of spray cooling of a hot plate to predict the unknown surface temperature, surface heat flux and convection heat transfer coefficient. To validate the accuracy of the results, the results of inverse method are compared to the results presented by Qiao and Chandra [1]. The results demonstrate that the computational results of surface heat flux and convective heat transfer coefficient converge for the short times and moderate times. However, for the large times, it gradually diverges until it reaches its maximum at ninety seconds and it remains almost constant for the rest of the time domain.
Keywords/Search Tags:Surface heat flux, Surface temperature, Inverse
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