Estimation of Spatially Distributed Thermal Properties of Heterogeneous Media with Non-Intrusive Measurement

Abstract

This article deals with estimation of spatially distributed thermal properties of two-dimensional heterogeneous media from the solution of inverse heat conduction problem. The experimental procedure involves sequential heating of sample at four discrete locations on one side and recording transient temperature on the other side non-intrusively. The inverse problem formulation is carried out as parameter estimation problem and the unknown parameters are estimated through minimization of sum of squared error between measured and simulated temperatures using Levenberg–Marquardt algorithm. The huge computational time required to calculate sensitivity matrix is reduced through parallel computation strategy. Numerical estimations are carried out with synthetic temperature and it is found that the resolution and accuracy of estimated spatially distributed thermal conductivity is in better agreement with the exact distribution when compared to volumetric heat capacity even at an error level of ± 0.1 K. Transient temperature response of the fabricated heterogeneous prototype is recorded using infrared radiation camera and the same is used for estimation of unknown parameters. The estimated thermal conductivity closely mimics the actual distribution. Therefore, this simple proposed method can be directly used in thermal tomography applications for identifying the shape and size of inclusions/inhomogeneities from the estimated thermal conductivity distribution alone.

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Notes on contributors

Sankaran Somasundharam

Sankaran Somasundharam completed his Ph.D. degree in the Department of Mechanical Engineering at Indian Institute of Technology Madras, Chennai. He is now working as Senior Assistant Professor at VIT University, Vellore. He received his bachelor's degree from PSG College of Technology, Coimbatore, India. His research interest includes estimation of thermo-physical properties using inverse parameter estimation technique, thermal energy storage for solar applications and renewable energy.

Kalvala Srinivas Reddy

Kalvala Srinivas Reddy is Professor of Mechanical Engineering at Indian Institute of Technology (IIT) Madras, Chennai. He is specialist in renewable energy technologies, concentrating solar thermal and PV systems, energy efficiency and environment. Presently, he is also honorary professor at University of Exeter, U.K. and Adjunct Professor, CEERI-CSIR, Chennai. He has authored more than 200 research papers in international journals and conferences. He coauthored a book on “Sustainable Energy and the Environment: A Clean Technology Approach” Published by Springer. He has executed several research projects related to solar energy and energy & environment sponsored by various national and international agencies. He is actively involved in development of Concentrating Solar Power technologies in India. He is associated with several industries on power generation, process heat, energy efficiency & conservation and characterization of engineering materials. He has received several awards such as WSSET Innovation award, and Shri J.C.Bose Patent award in recognition of his research work.