Investigation of rib’s effect in cavitation on an axisymmetric separated flow over a longitudinal blunt circular cylinder

摘要

The current investigation, determines the effects of rib shape and its parameters on an inner flow in which a circular cylinderexist in the middle. The problem is solved in 2 dimensional methods and the distance from the channel’s entranceto cylinder is 125 mm. Ansys 14.5 is used for modeling the geometry and meshing of the problem and for modeling theturbulence the k − ε (realizable) is employed. In this study rib and its four parameters of pitch (p), length (h), rib’s height (e)and the distance from the cylinders’ head to start of rib (a) in a cavitation flow is investigated. The results show that noneof rib’s parameters has a direct relation with void fraction. The values for these parameters are different for the maximumor the minimum cavitation; namely if a rib’s pitch increases and surpasses a specific value, it will reduce the effect of theprevious rib in the flow. In fact, the turbulence eradicates before it become more turbulent by the next rib. On the otherhand, if the rib’s pitch is too small the flow traps between the two ribs and stagnation happens which is the key elementin plummeting the pressure and forming cavity. For other parameters either no correlation with void fraction is observed.