Direct numerical simulation of a non-equilibrium three-dimensional turbulent boundary layer over a flat plate

Abstract

Abstract

Direct numerical simulation of a turbulent boundary layer over a bump with strong pressure gradients

“…Similar behaviour in the presence of internal layers was also reported by Baskaran et al. (1987); by Antonia & Luxton (1971, 1972) due to sudden changes in surface roughness; and by Abe (2020) due to sudden imposition of a surface spanwise velocity. The internal layer has a fairly constant Reynolds shear stress throughout the FPG as suggested by the small variation in the magnitude of the inner peak in figure 11( d ).…”

A Lagrangian relaxation towards equilibrium wall model for large eddy simulation

“…Vardy & Brown (2003) and Vardy et al (2015) attempt to understand the wall shear stress for water hammer pipe flows. Experimental and numerical studies of pulsatile flows have been performed by Scotti & Piomelli (2001) Then there are studies with step changes in either the wall boundary condition or in the pressure forcing such as the sudden spanwise wall movement of Coleman et al (1996), Tang & Akhavan (2016) and Abe (2020), the sudden spanwise pressure gradient of Moin et al (1990) and Lozano-Durán et al (2020) or a change in the direction of the pressure gradient forcing (for a variety of directions) as done in de Wiart, Larsson & Murman (2018). One of the common observations amongst all of these flows is the existence of a laminar Stokes layer near the wall.…”

“…They further showed the similarity of the wall stress during the acceleration phase of pulsatile flows with the initial phase of streamwise accelerating flows. For the sudden spanwise wall movement and SSPG, the spanwise velocity and wall stress follows Stokes' first problem during the early response (Coleman et al 1996;Abe 2020;Lozano-Durán et al 2020).…”

“…Then there are studies with step changes in either the wall boundary condition or in the pressure forcing such as the sudden spanwise wall movement of Coleman et al. (1996), Tang & Akhavan (2016) and Abe (2020), the sudden spanwise pressure gradient of Moin et al. (1990) and Lozano-Durán et al.…”

“…For the sudden spanwise wall movement and SSPG, the spanwise velocity and wall stress follows Stokes’ first problem during the early response (Coleman et al. 1996; Abe 2020; Lozano-Durán et al. 2020).…”