Modeling and Numerical Simulation of Wings Effect on Turbulent Flow between two contra-rotating cylinders

Abstract

Many industries in the world take part in the pollution of the environment. This pollution often comes from the reactions of combustion. To optimize these reactions and to minimize pollution, turbulence is a funda- mental tool. Several factors are at the origin of turbulence in the complex flows, among these factors, we can quote the effect of wings in the rotating flows. The interest of this work is to model and to simulate numeri- cally the effect of wings on the level of turbulence in the flow between two contra-rotating cylinders. We have fixed on these two cylinders eight wings uniformly distributed and we have varied the height of the wings to have six values from 2 mm to 20 mm by maintaining the same Reynolds number of rotation. The numerical tool is based on a statistical model in a point using the closing of the second order of the transport equations of the Reynolds stresses (Reynolds Stress Model: RSM). We have modelled wings effect on the flow by a source term added to the equation tangential speed. The results of the numerical simulation showed that all the average and fluctuating variables are affected the value of the kinetic energy of turbulence as those of Reynolds stresses increase with the height of the wings

Influence of Rotating Speed Ratio on the Annular Turbulent Flow between Two Rotating Cylinders

“…The system of the Figure 1 is the same as that used by Raddaoui [16], it represents a device with an annular space between two cylinders in uniform rotation movement; the fluid considered in annular space is incomepressible. The value of interior ray is R 1 = 100 mm and the external ray is R 2 = 200 mm, the two cylinders are of the same length h = 200 mm and can turn in the same direction or in the opposite direction.…”

“…As we do not have measurements for annular flows treated in this work, we compare the RSM model simulation to experimental LDA measurements done by Raddaoui [16] for rotating flows between two contra-rotating discs ( . For mean velocities V r and V θ , we note that the RSM model results are in a no far from the experimental measures and this is valid for all the flow sections, unlike the k-ε model which falls short of describing correctly this kind of flow especially on the level of the median plane where turbulence is maximum because of strata torsion.…”