A Study on Inverse Problems of Realistic Heat Transfer Systems

Abstract

This thesis aims to contribute towards the optimization of energy requirements. This is achieved by finding the solution of inverse problems in the heat transfer setting. To enhance the performance efficiency of a thermal system, the controlling parameters should be tuned. This is realized for composite walls, where performance is marked through efficiency. Besides, to have deeper information about a practical system, various important thermal parameters are to be estimated. This is procured by performing real-time experiments on fins, where the time-dependent heat flux is retrieved. Marking the presence of tumor through inverse detection of blood perfusion rate demonstrates the versatility of the process. Apart from the retrieval of parameters, the current work focuses on the different techniques for inversion. With the presence of a large number of inversion algorithms for Inverse heat transfer problems (IHTPs) and non-IHTPs, a need for review to have a holistic view is seen. To accomplish the task, an exhaustive literature review, based on regularization techniques and methods to find the solution of inverse problems is performed. With the motivation of selection of the inversion technique best fit for a given problem, the comparison was made for a general inverse problem. Having the exact solution is necessary, to compare the numerical solutions, of a non-linear problem. In this purview, the Adomian decomposition method is established for non-linear heat transfer in double-layered walls. The closed-form of temperature is obtained, with a maximum efficiency of 98.32% for the specific thermal parameters. The contribution of this analysis is seen through its application in an industrial furnace. In the subsequent analysis, the non-suitability of gradient-based algorithms is identified. For the IHTPs, complexity increases due to the presence of several temperature-dependent properties, thus evolutionary algorithms were recognized suitable for the solution of IHTPs. Unlike the steady-state analysis of composite