Multidisciplinary flow/thermal and induced stresses in convectively cooled structures

A multidisciplinary finite element methodology with stabilizing features to prevent undue oscillatory solution behavior for the velocities, pressure, and temperature fields and which subsequently permits computations of the resulting thermal loads for the associated stress analysis is described for convectively cooled structures subjected to high-intensity localized heating. Of particular interest are the influences of coolants that serve to cool the structure whose exposed skin is permitted to radiate to outer space. Of the three coolants investigated - namely, liquid hydrogen, water, and liquid sodium - it is observed that the liquid sodium serves as an effective coolant that is consistent with past related studies. The resulting thermally induced stresses arising from the assumption of elastic and a materially nonlinear elastoplastic model are also evaluated. The nonlinear model seems more realistic because of the situations encountered at high temperatures and as expected yields lower values of the stresses. Illustrative examples of a flat skin structure and a curved skin geometry representing the cowl leading edge are analyzed for the flow/thermal and induced stresses.