Dual reciprocity boundary element analysis of inverse heat conduction problems

This paper presents an application of the dual reciprocity boundary element method (DRBEM) to inverse heat conduction problems. To dear with the ill-p osed nature of the problem, iterative regularization methods of conjugate g radient type have been used. Preconditioned biconjugate (PBCG) method has b een used for the solution if the discretized boundary element system has as many equations as the total number of unknowns. Preconditioned conjugate g radient (PCG) method has been utilized for the general case in which more e quations are available than unknowns, Numerical results show that PBCG algo rithm is useful only for inverse problems having unspecified boundary condi tions on a small fraction of the boundary, whereas the PCG algorithm works well for any problem. Flux estimates with both the methods are seen to be s ensitive to the location of measurement points and measurement errors. In c ontrast, temperature estimates are very accurate, nearly insensitive to mea surement errors, and only weakly sensitive to location of measurement point s. Further, constant elements work much better than the linear elements in terms of accuracy as well as stability of the numerical solution, and shoul d be preferred in DRBE analysis of inverse heat conduction problems. (C) 20 01 Elsevier Science B.V. All rights reserved.