Fluctuating lift and drag forces by Karman vortex shedding and pressure distributions around a stationary circular cylinder were measured in a water cross flow at supercritical Reynolds numbers. The surface roughness of the cylinder was a mirror-polished surface. Turbulence intensities of the incoming filow were changed from 1% to 13% in order to investigate the effect on vortex shedding characteristics. As the turbulence intensity increased in supercritical region, flow separation location of the boundary layer on the cylinder surface moved forward, Strouhal number decreased from about 0.48 to 0.29 and the fluctuating lift force by Karman vortex shedding increased.

Increasing turbulence intensity in supercritical regions leads to a shift in flow separation location, a decrease in Strouhal number, and an increase in fluctuating lift force by Karman vortex shedding.

超臨界レイノルズ数領域における直交流中の静止円柱からの渦放出特性 ( 流体関連振動・騒音等)

Key Takeaway: Increasing turbulence intensity in supercritical regions leads to a shift in flow separation location, a decrease in Strouhal number, and an increase in fluctuating lift force by Karman vortex shedding.