Comparison of design methods for negative pressure gradient rotary bodies: A CFD study

Abstract

Computational fluid dynamics (CFD) simulation is used to test two body design methods which use negative pressure gradient to suppress laminar flow separation and drag reduction. The steady-state model of the Transition SST model is used to calculate the pressure distribution, wall shear stress, and drag coefficient under zero angle of attack at different velocities. Four bodies designed by two different methods are considered. Our results show the first method is superior to the body of Hansen in drag reduction and the body designed by the first method is more likely to obtain the characteristics of suppressing or eliminating separation, which can effectively improve laminar flow coverage to achieve drag reduction under higher Reynolds number conditions. The results show that the negative pressure gradient method can suppress separation and drag reduction better than the second method. This successful design method is expected to open a promising prospect for its application in the design of small drag, small noise subsonic hydrodynamic hull and underwater weapons.

Design of short Venturi flow meters for incompressible and isothermal flow applications

“…This proximity of the flow to the surface keeps it stable and relatively free of turbulence [ 24 ]. These findings align with Liu et al [ 25 ], who observed that negative pressure gradients help prevent flow separations. Therefore, with the convergent section less susceptible to flow separation, θ c can be increased without adverse effects.…”

An experimental investigation and flow field analysis on cycling clothing fabrics with grooved surface

“…Therefore, drag reduction can be achieved by suppressing or eliminating separation. 34,35 Pressure distribution. The pressure distributions of smooth and grooves surface are simulated at R e = 1.19 × 10 5 and 1.59 × 10 5 .…”