Reconstruction of the heat transfer coefficient at the interface of a bi-material

ABSTRACT

The knowledge of heat transfer behaviour of composite thermal systems requires the characterization of the heat transfer coefficient at the contact interfaces between the constituent materials. The present work is devoted to investigating an inverse problem with generalized interface condition containing an unknown space- and time-varying interface coefficient from non-invasive temperature measurements on an accessible boundary. The uniqueness of the solution holds, but the problem does not depend continuously on the input measured temperature data. A new preconditioned conjugate gradient method (CGM) is utilized to address the ill-posedness of the inverse problem. In comparison with the standard CGM with no preconditioning, this method has the merit that the gradient of the objective functional does not vanish at the final time, which restores accuracy and stability when the input data is contaminated with noise and when the initial guess is not close to the true solution. Several numerical examples corresponding to linear thermal contact and nonlinear Stefan-Boltzmann radiation condition are tested for determining thermal contact conductance and Stefan-Boltzmann coefficient, respectively. The numerical results in both one- and two-dimensions illustrate that the reconstructions are robust and stable.

KEYWORDS:

• Thermal contact conductance
• Stefan-Boltzmann coefficient
• preconditioning
• conjugate gradient method
• nonlinear inverse problem

SUBJECT CLASSIFICATION CODE:

• 65L09

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China under [grant number 11502058]; and the National Basic Research Program of China (or 973 Program) under [grant number 2015CB655200]. The first author would like to acknowledge the financial support from the China Scholarship Council (CSC).