OSCILLATORY FLOW WITHIN POROUS TUBES CONTAINING WALL OR CENTRAL BAFFLES

We report numerical simulation on steady and oscillatory flow in a baf fled tube. Results are reported for both central and wall periodically spaced baffles. Results are also reported for a porous tube when flow oscillations are associated with the net flow. When the Strouhal numb er decreases, an additional vortex is formed close to the wall. When S t decreases even further this one dominates. Wall shear rate and press ure drop calculations were carried out and results show that wall shea r rate is a linearly increasing function of Reynolds number and that c entral baffles achieve greater wall shear rates. There is a phase-shif t in pressure drop, which is a monotonically increasing function of pe ak Reynolds number and Strouhal number. The vortex strength at the ins tants of zero flow is larger for wall baffles and there is a maximum w ith respect to Strouhal number.