Numerical Simulation Of Pulsatile Flow

This paper conducts numerical simulation of heat transfer and resistance characteristics of a pipe under pulsatile flow. The influence of velocity, amplitude and frequency of pulsatile flow on heat transfer and resistance characteristics is analyzed. The cause of phase shift between flux curve and pressure drop curve is also analyzed.Wall temperature, cross-sectional mean fluid temperature, heat exchange coefficient, and pressure drop oscillate when the flow is pulsatile.The instantaneous Nu number is influenced strongly by flow oscillation, but the time-averaged Nu number is not influenced. So heat transfer is neither strengthened nor weakened. The total pressure drop could be negative due to the presence of oscillation accelerating pressure drop. When flow is turbulent, turbulence intensity increases because of flow oscillation, and viscosity dissipation increases slightly. So the time-averaged pressure drop increases slightly. When flow is laminar, time-averaged pressure drop increases a lot.Oscillation accelerating pressure drop arisen from oscillation acceleration induces the phase shift between flux curve and pressure drop curve. When oscillation accelerating pressure drop increases relative to fraction loss, phase shift increases between 0 andπ/2.