A DNS study on the effects of convex streamwise curvature on coherent structures in a temporally-developing turbulent boundary layer with supercritical water

• Numerically simulated forced-convection turbulent flow over convex-curved surface.
• Analyzed effects of curvature and supercritical thermal state on heat transfer.
• Near-wall streaks spaced farther apart due to curvature-induced radial equilibrium.
• Curvature and supercritical effects on turbulence are of comparable magnitude.

Direct numerical simulation (DNS) results are used to establish the effect of convex streamwise curvature on the development of turbulent boundary layers, and the effect of such curvature on the forced-convection heat transfer variations observed at certain supercritical thermodynamic states. The results illustrate the stabilizing effects of this flow geometry through modification of the structure and distribution of hairpin-like vortical flow structures in the boundary layer. Furthermore, enhancement of convective heat transfer realized at a particular heat flux-to-mass flux ratio with the working fluid at a supercritical state is observed to be reduced by the stabilizing effect of convex surface curvature.