Forcing of unsteady separated flow and convective heat transfer via bulk upstream oscillations

Simulations are presented for the unsteady separated-reattaching flow and associated heat transfer over a long rectangular plate subjected to an oscillatory inlet velocity, U=1+Apsin2πfpt. The two-dimensional simulations are performed at a Reynolds number of 1000 by solving the time-dependent Navier–Stokes and energy equation using a finite volume method. The computations are performed on a 300×100 grid, using centered second-order accurate spatial discretization, and a third-order time-stepping scheme. The effect of forcing is investigated by exploring the response of the flow over a range of frequencies up to the 60th harmonic of the natural vortex shedding frequencies and for velocity perturbation amplitudes up to 20% of the free stream. Forcing of the flow is found to radically alter the dynamics of the flow and results in significantly higher local heat transfer rates.