AN IMMERSED MESH BLOCK (IMB) APPROACH FOR CONJUGATE HEAT TRANSFER PREDICTIONS

摘要

Aerothermnal design capability for cooled high pressure turbines depends on resolving complex physical processes such as coolant mixing, coupled fluid-solid convection-conduction heat transfer, and their interactions. This paper presents the development of the generalised Immersed Mesh Block 2 (IMB2) method, which allows high resolution predictions of all these processes to be conducted for a fully cooled turbine stage within a couple of days. The method consists of creating high density meshes of cooling holes to capture the high flow gradients in the fluid domain and separately, generating corresponding meshes for the local metal layer with high temperature gradient. These can then be inserted rapidly into a host turbine domain for conjugate heat transfer as immersed mesh blocks for fluids (IMB_f and metals (IMB_m). In this way, conjugate heat transfer meshes of entire rows of cooling holes can be generated and inserted into a host mesh within minutes. The composite domain is then solved with simultaneous coupling between all the fluid and metal IMBs, as well as the host mesh. The paper presents the methodology of this approach and demonstrates its application to a transonic, fully cooled nozzle guide vane.