Analytical and CFD investigation of oscillating flow in pulse tube of thermal lag engine

An analytical and CFD method are used to investigate the oscillating flow and friction coefficient in the pulse tube of the Thermal Lag Engine (TLE). The coefficient of friction reciprocating gas flow in the tube and the resulting phase shift angle between the axial velocity of the oscillating flow and gas pressure were obtained using analytical and CFD methods. The efficiency of a pulse tube has been proposed, which can be used to describe the loss of pulse tube quantitatively. The resulting phase angle shift between gas velocity and pressure is obtained analytically with account of friction in oscillating flow in a tube. The velocity profiles and phase angle are in good agreement with the CFD simulation results.