Experimental Analysis of Cavitaion E ects on Drag Force and Back Pressure of Circular Cylinder with Free Turbulence


Department of Mechanical Engineering,Sharif University of Technology


Abstract. The characteristics of a cavitation water tunnel test setup and the experiments of cavitation
around a circular cylinder with free stream turbulence are presented in this paper. The Reynolds number
ow is limited in the range of 1:26105 to 3105 and the far upstream
ow has free turbulence. Drag
force, back pressure, location of cavitation inception, length of cavity and appearance of cavitation are
measured or observed and their results are presented here. It was found that the cavitation e ects on the
boundary layer and separation of
ow over the cylinder and drag force become minimum at the cavitation
number of 1.94. The cavitation inception occurs in the sub-layer and at an angle of about 105, with
respect to
ow direction (inception location depends on Reynolds number). The back pressure coecient
becomes maximum at the cavitation number of 1.94.