Abstract In this paper, the flow past a rotating circular cylinder placed in a compressible uniform stream is investigated via numerical two-dimensional computations. Then, the effect of the free stream Mach number and the non-dimensional rotation rate, α (ratio of the surface speed and free-stream speed) of the cylinder are studied. For this purpose, the flows with free-stream Mach numbers between 0.05 and 0.4 are past the cylinders with wide ranges of rotation rates. A constant Reynolds number of 200 is used for calculations. The numerical simulation of flow is based on discretization of convective flaxes of the unsteady Navier-Stokes equations by second-order Roe’s scheme and an explicit finite volume method. Because of the importance of the time dependent parameters in the solution, the second-order time accurate is applied by dual time stepping approach. In order to validate the operation of computer code, some results are compared with experimental and numerical data. The results of this study showed that the effects induced by the flow compressibility caused the interesting variations on the flow around the cylinder even in low Mach numbers, so that in spite of incompressible flows, the lift force generation was bounded. It was also observed that with increase in the free-stream Mach number, the maximum generated lift coefficient was decreased.

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