turbine question

clifford bradford

I have a question about design of high temperature internally cooled turbines.

In the design of these blades the aerodynamic design step is usually done before the thermo-structural design. ie the blade shape is (provisionally) determined and then the internal cooling passages necessary are designed afterward. since the erodynamic design is done (using CFD) before the internal cooling analysis how is the thermal boundary condition on the blade specified. is it adiabatic (at least for the first cut)? my quandary is that the fluid flow constitues only a portion of the thermal field which also includes the as yet undesigned blade internals. but the fluid flow depends on the thermal field.

if so is an iterative technique/procedure used? can someone outline it for me?