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.

Summary We propose a full Eulerian incompressible solid‐fluid interaction scheme capable of achieving high parallel efficiency and easily generating meshes for complex solid geometries. While good scalability of a full Eulerian solid‐fluid interaction formulation has been reported by Sugiyama et al, their analysis was carried out using uniform Cartesian mesh and an artificial compressibility method. Typically, it is more challenging to achieve good scalability for hierarchical Cartesian meshes and a fully incompressible formulation. In addition, the conventional full Eulerian methods require a large computational cost to resolve complex solid geometries due to the usage of uniform Cartesian meshes. In an attempt to overcome the aforementioned issues, we employ the building‐cube method, where the computational domain is divided into cubic regions called cubes. Each cube is divided at equal intervals, the same number of cubes is assigned to each core, and the spatial loop processing is executed for each cube. The numerical method is verified by computing five numerical examples. In the weak scaling test, the parallel efficiency at 32768 cores with 32 cores as a reference is 93.6%. In the strong scaling test, the parallel efficiency at 32768 cores with 128 cores as a reference is 70.2%.

The flow over a stationary golf ball has been numerically investigated by conducting large-eddy simulations in the subcritical, critical and supercritical regimes. A direct comparison of features of flow fields was made to a smooth sphere model. Particular attention was paid to the effect that the golf ball dimples have on the development of lateral force and wake structures. In the subcritical regime, the lateral force varies irregularly in time for both the golf ball and the smooth sphere, and the wake structures of these two models appear to be similar, indicating the limited effect of the surface roughness on the flow behaviors in this regime. In the critical regime, both the golf ball and the smooth sphere exhibit a larger magnitude lateral force oscillation compared to the subcritical cases, while the wavelengths of the flow structures show differences between the golf ball and the smooth sphere. In the Makoto Tsubokura Flow Turbulence Combust supercritical regime, both the golf ball and the smooth sphere are subjected to a nonzero lateral force during a long time interval. However, the magnitude of the lateral force acting on the golf ball is much smaller due to the relatively more concentrated and less asymmetric wake structures compared to the smooth sphere.