Wall-modeled large eddy simulation of Fernandez-Gausti squircles

The Fernández-Guasti (FG) squircle provides a continuous parametric transformation of internal wall-bounded flows from pipes to ducts. In the pipe limit of the FG squircle, no secondary flows are present, whereas in the duct limit, Prandtl’s secondary motions of the second kind emerge. This talk first presents a DNS database spanning varying degrees of squareness parameter and friction Reynolds number, with the input space sparsely sampled in a cost-effective manner.

Subsequently, a wall-modeled large eddy simulation (WMLES) campaign is performed, reducing computational cost per simulation by three orders of magnitude. The resulting WMLES data are evaluated against the DNS database. We primarily investigate the accuracy of WMLES in capturing key quantities of interest which are, mean streamwise velocity, cross-sectional mean secondary velocity, and Reynolds stresses.