Numerical Study on the Decay and Amplification of Turbulence in Oscillatory Pipe Flow

摘要

Results of three-dimensional direct numerical simulations of oscillatory pipe flows at two high dimensionless frequencies W_o ∈ {13, 26} are discussed. Starting froma fully-developed turbulent velocity field, the flows either relaminarise or reach a conditionally or fully turbulent state, depending on Re and Wo. Analysing the temporal evolution of several phase-averaged quantities, reveals different behaviour of the wall shear stress and the RMS velocity profiles, while the integral bulk flow only reflects minor differences. Utilising two different initial conditions do not significantly influence the developing oscillatory bulk flow.