Optimization of Thicknesses of Walls and Interior Struts
Next, the designer could run a 3-D Navier-Stokes coolant flow analyst!, code and compare its predicted coolant passage wall temperatures with the temperatures obtained in the previous task. The objective could be to minimize the difference in coolant passage surface temperatures obtained from the Navier-Stokes coolant flow analysis code and the heal conduction BEM code. This will be achieved by further altering the shapes of the 3-D coolant passages. This iterative modification of the 3-D coolant passages is required since all thermal boundary conditions on the external and internal surfaces must be compatible with each other and with the corresponding flow fields.
In addition, the converged configuration of the 3-D coolant passages might not be desirable from the manufacturing point of view and might not be structurally sound. Thus, the designer should use the converged configuration of the 3-D coolant passages only as an intelligent initial guess to help in the structural design. For this purpose the designer might wish to specify the locations of mid-planes of the walls separating the converged shapes of 3-D coolant passages and treat them now as mid-planes of the future intenor struts. Other design constraints and requirements may be considered and incorporated. This automatically defines the initial thickness distnbutions of each strut and the wall. These thicknesses can be parameterized with a small number of (3-splinc coefficients which can then be the design vanablcs in the optimization process