A substructure method and a dual reciprocity boundary element method(DRBEM) are applied to calculate four-pole parameters and transmission loss of ducts and silencers with complex flow.Basic principle and numerical procedure are introduced in detail.It is shown that the DRBEM is valid to compute four-pole parameters and transmission loss of ducts and silencers with subsonic complex flow with higher Mach number.The substructure method reduces numerical complexity of the DRBEM and improves accuracy and computation speed.

In this paper, a finite differential heat transfer computer code HEATING-5 has been used to model the thermal hydraulic problems of a He-cooled first wall for fusion breeder. The numerical techniquws of solving steady and transient state heat conduction equations are presented. The numerical calculations have been done. The temperature distributions of the coolant in different flow locations have been calcultaed by analytical method as the iuput parameters of the HEATING-5 code. in order go conform the fluid terms in the energy balance equation which are not included in the original code. Meanwhile, another finiteelement heat transfer computer code AYER, which includes forced convection flow terms in the heat transfer equation, is also used to solve the same problem. It shoes that the results by using HEATING-5 code to model coolant flow heat transfer are well consistent with that by using AYER code.