Study on the Change of Incident Direction and Incoming Flow Velocity to the Reattachment Point and the Center Position of the Large Vortex

摘要

This paper establishes a model with the variation of the standard angle with the height of the step. Numerical simulation is carried out to study the influence of the change of the incident direction and the incoming velocity on the large eddy structure and the length of the recirculation zone in the reattached shear layer under different standard angles. Finding that with the increase of the incident angle p, the length of the recirculation zone tends to increase firstly and then decrease. The large vortex center position Y/H firstly maintains a small range of fluctuations; when the incident angle p reaches a certain value, the large vortex center position suddenly rises sharply to a certain value. The center position of the large vortex decreases again when p continues to increase. When the Reynolds number increases from 150 to 300, the value of Xr/H will suddenly increase sharply and the position of the large vortex will have a significant downward trend. When the Reynolds number is greater than 300, the length of the recirculation zone will remain unchanged from the center of the large vortex. That is the recirculation zone length and the Y/H value of the center position of the large vortex is not affected by the Reynolds number.