CALCULATING HEAT CONDUCTION TRANSFER FUNCTION THROUGH MULTI-LAYER SLAB USING MODEL REDUCTION METHOD

摘要

Heat conduction transfer function (CTF) method is suitable to deal with the transient heat-conduction through multi-layer slabs encountered in engineering practice frequently. To determine the CTF efficiently, a model reduction approach combining Routh and Pade approximations is developed. Firstly, the transfer function in frequency domain is expanded in the form of power series with infinite terms. Secondly, the Routh approximation is used to determine the denominator coefficients of the reduced CTF. Thirdly, the numerator coefficients of the reduced CTF are evaluated by the Pade approximation. Finally, a direct way from the reduced CTF in frequency domain to that in z-domain is presented. Case study demonstrates that high precision can be obtained by the reduced model in fairly low order.