Estimation of thermal contact resistance in fin-tube heat exchanger using inverse heat transfer methods

Thermal contact resistance (TCR) is a very important phenomenon in heat transfer problems, such as power generation, air conditioning, refrigeration, aerospace, etc. due to the complex mechanism of heat transfer in the contact surfaces; measurements and calculations of the TCR have many difficulties and problems. Today, one of the effective methods to investigate these problems is the use of inverse heat transfer. The objective of this work is to estimate the contact heat transfer coefficient (reverse of TCR) between the tube and its fin in heat exchanger. Two different methods, consisting of Levenberg-Marquardt for parameter estimation and conjugate gradient with adjoint problem for function estimation conjugate gradient method (CGM), are used. Results show that the CGM is successfully applied for the solution of the inverse problem to determine the unknown time-dependent TCR.