This is a continuation of our companion paper (Kida 2020b Fluid Dyn. Res.) in which the steady flow in a precessing spheroid is studied in the strong spin and weak precession limit, and the elliptic flow with uniform vorticity, the direction of which is perpendicular to the spin axis on the plane spanned by the spin and the precession axes, is shown to be excited in the interior inviscid region. In this paper we examine the boundary-layer flow connected to this elliptic flow and also the higher-order inviscid flow modified by this boundary-layer flow. The explicit expression of the velocity and pressure fields is obtained for arbitrary aspect ratio c of the polar and equatorial radii of the spheroid. The boundary-layer approximation breaks down at two critical circles on which the boundary-layer thickness as well as the normal component of velocity diverge to infinity. The flow field in the neighborhood (called the critical regions) of the critical circles is analyzed to find the same structure, up to scales, as that for a sphere. The radial component of velocity in the critical region induces the conical shear layers along the characteristic cones in the inviscid region. They reflect on the spheroid surface, and the reflection takes place endlessly in general. On the other hand, it is proved that for a spheroid of which the aspect ratio is expressed as (m/n being an irreducible fraction) the reflection terminates at (n − 2) times and the conical shear layers form a regular pattern. Since such special values of c are distributed densely over all the positive numbers, we may observe practically always a regular pattern of the conical shear layers. Such closed conical shear layers are clearly visualized by the pressure field numerically calculated in the asymptotic formulation. Furthermore, the total angular momentum of the steady flow is expressed explicitly up to the non-trivial leading order for all the three components over the whole range of the aspect ratio.

这是我们同伴论文 (Kida 2020b Fluid Dyn. Res.) 的延续，其中研究了强自旋和弱进动极限下进动球体中的稳态流动，以及具有均匀涡度的椭圆流，其方向为在自旋轴和进动轴所跨越的平面上垂直于自旋轴，显示在内部无粘性区域中被激发。在本文中，我们研究了与该椭圆流相连的边界层流以及由该边界层流修正的高阶无粘性流。获得任意纵横比c的速度场和压力场的显式表达式球体的极半径和赤道半径。边界层近似在两个临界圆上分解，在这两个临界圆上边界层厚度以及速度的法向分量发散到无穷大。分析临界圆的邻域（称为临界区域）中的流场以找到与球体相同的结构，直到尺度。临界区速度的径向分量在无粘性区沿特征锥体产生锥形剪切层。它们在球体表面上反射，并且反射通常无休止地发生。另一方面，证明了对于长宽比表示为( m / n是一个不可约的分数）反射终止于 ( n  - 2) 次并且锥形剪切层形成规则图案。由于c 的这种特殊值密集地分布在所有正数上，我们实际上可以观察到锥形剪切层的规则模式。这种封闭的锥形剪切层可以通过渐近公式中数值计算的压力场清晰地可视化。此外，在整个纵横比范围内，稳定流的总角动量被明确表达为所有三个分量的非平凡领先阶次。