Development of conjugate heat transfer capability to an unstructured flow solver: U(2)NCLE.

摘要

A precise prediction of the heat loads in metal materials in contact with the hot gas is an increasingly demanding problem in the design phase of the complex cooling schemes in the modern turbine engines. The coupled calculation of the fluid flow and the heat transfer is a promising approach as heat transfer coefficients are not necessary in the calculation and the heat transfer itself is part of the calculation and can be derived from local heat fluxes. Therefore, it is useful to incorporate an appropriate scheme for directly coupled heat transfer computations (conjugate heat transfer), capable of handling complex geometries into the existing computational fluid dynamics (CFD) codes. The intent of the present work is to add the conjugate heat transfer solving capability to an existing flow solver.; The coupled approach is achieved by maintaining a continuous local heat flux and a common temperature at the points along the fluid-solid interface. At every iteration, the temperature which is directly calculated via the equality of the local heat fluxes passing the fluid-solid contacting cell faces serves as the thermal boundary condition on the interfaces, instead of traditional isothermal/adiabatic thermal boundary conditions. In the solid domain, simplified energy equation is solved using the discretization and computational methods which have been used in the flow by introducing an effective equation of state. The connectivity is built for the points at the fluid-solid interfaces in order to communicate the thermal conditions with each other.; Validation of the developed conjugate capability has been investigated. Computed results have been compared with theoretical or experimental results for laminar flat plate, high pressure guide vane, cooled plate, and effusion-cooled plate. All results obtained thus far compare rather favorably with theoretical or experimental results.