Negative Magnus lift on a rotating sphere at around the critical Reynolds number

Abstract

Maximum entropy states of quasi-geostrophic point vortices Phys. Fluids 24, 056601 (2012) Effect of swirl decay on vortex breakdown in a confined steady axisymmetric flow Phys. Fluids 24, 043601 (2012) Simulations of turbulent rotating flows using a subfilter scale stress model derived from the partially integrated transport modeling method Phys. . The numerical methods used were first validated on a non-rotating sphere, and the spatial resolution around the sphere was determined so as to reproduce the laminar separation, reattachment, and turbulent transition of the boundary layer observed in the vicinity of the critical Reynolds number. The rotating sphere exhibited a positive or negative Magnus effect depending on the Reynolds number and the imposed rotating speed. At Reynolds numbers in the subcritical or supercritical regimes, the direction of the Magnus lift force was independent of the rotational speed. In contrast, the lift force was negative in the critical regime when particular rotating speeds were imposed. This negative Magnus effect was investigated in the context of suppression or promotion of boundary layer transition around the separation point.

Numerical Investigation of the Flow Around a Golf Ball at Around the Critical Reynolds Number and its Comparison with a Smooth Sphere

“…Meanwhile, the second-order central difference scheme is used for the spatial derivatives with 5 % of the first-order upwind scheme being blended for the calculation of the convection term for the sake of numerical stability. For the time advancement, the first-order Euler implicit scheme is used, which coincides with the corresponding scheme in Muto's [10] work. According to the estimation provided by Muto et al [10], the simulation results showed very limited difference between the first-order Euler scheme and the third-order Adams-Moulton scheme when relatively fine meshes were allocated around the sphere and the Courant number was kept to be less than 1.8.…”

“…They provided insight into both the statistical features, such as the prediction of the mean drag force, and the instantaneous features including how the aerodynamic forces developed over time. Muto et al [10] extended the numerical work to the research on a rotating sphere. In this study, Large-eddy simulations (LES) were conducted for a sphere in both stationary and rotating conditions, and the phenomenon that a lift force pointing to the direction opposite to the one suggested based on the potential theory, which is namely the negative or inverse Magnus effect, was successfully reproduced and its physical mechanism was discussed.…”

Three-dimensional simulation of a self-propelled fish-like body swimming in a channel

“…Webb (1993) investigated the swimming performance of steelhead trout in channels with solid or porous walls and highlighted the wall effect on kinematics. However, considering the relatively low Reynolds number in this study, the effect is considered (Muto, Tsubokura, & Oshima, 2012; http:// www.ciss.iis.u-tokyo.ac.jp/rss21/), which adopts an unstructured finite-volume procedure with vertex-cen tered-type storage on a grid. The third-order upwind difference scheme is used to discretize the spatial derivatives.…”

Toward the development of an anisotropy-resolving subgrid-scale model for large eddy simulation

“…Note that for all three test cases, the grid resolution in the wall-normal (y) direction is the same as that of the original DNS data. A posteriori calculations were performed using an unstructured finite-volume procedure that was almost the same as that used by Muto et al (2012), where vertex-centered type storage was used on a grid. The second-order central difference scheme was used to discretize the spatial derivatives except for the convection term of k S GS (Eq.…”