High aspect ratio cooling channels (HARCC) in expander cycle engines improve heat transfer by fin effect with the benefit of reduced pressure drop across the cooling passage. However, exact mechanism within channel that lead to improved performance have not been fully revealed by either experimental or numerical studies because of severe operational conditions such as high Reynolds number, the supercritical state of the coolant and asymmetric heating. The computational analyses described in the paper and addressed toward providing improved understanding of the detailed flowfield mechanisms that control heat transfer in HARCC's. The computational model is a full three-dimensional analysis that includes real property effects at pertinent supercritical state of cryogenic fluid as well as the conjugate heat transfer between the fluid and the solid. A turbulent model incorporating a nonlinear stress-strain model in implemented to assess the effect of the secondary flow in non-circular duct that arises from streamwise vortices in the corners.
展开▼
