Immersed Mesh Blocks (IMB) for film cooling

Immersed Mesh Block (IMB) Development  

The development is motivated by the recognition that there is a huge length scale difference  between the mesh resolution for an aerodynamic design and that for a cooling design. Given a common sequence of cooling design follows an aerodynamic design, it would make sense that cooling design could be based on the same baseline aerodynamic mesh for consistence. This is the basic consideration for developing  the cooling resolved fine mesh blocks which can be easily ‘super-imposed’ (in the meshing part) on the base-aerodynamic mesh. This itself is similar to the general overset gridding approach. The distinctive features associated with ‘blocking’ for turbine film cooling are:

a) Cooling hole geometries very similar to each other. Hence multi-hole in one row can be reproduced by simple multiplication. In fact, the same mesh blocking topology can be easily deformed to fit into  holes with slightly different geometries.

b)  easy adding, removing and moving blocks on a blade surface can be easily done without going back to the solid modeler and mesh generator, which often tends to be source of problems/bottle-necking.     

References:

-B. Lad, B.  and  L. He, “Use of an Immersed Mesh for High Resolution Modeling of Film Cooling Flows”, Journal of Turbomachinery, Vol.135. No.1, 011022, Jan 2013.

-B. Lad, B.,  L. He, “An Immersed Mesh Block (IMB) Approach for Coupled Fluid-Solid Aerothermal Prediction”, ASME Paper GT2013-94383.