Analytical investigation of oscillating flow heat transfer in pulse tubes

In the present paper, a two-dimensional compressible oscillating flow in the tube section of apulse tube refrigerator system is modeled, based on the successive approximation method. in this respect,the variables are expanded up to second-order terms. for pulse tubes with an outer adiabatic surface, theconservation equations of mass, momentum, energy, and the equation of state for the ideal gas are applied.the effects of operating frequency and taper angle on the temperature distribution, heat transfer behavior,and time-averaged enthalpy flow during a cycle are investigated. increasing the frequency leads to a higherheat transfer rate in the pulse tube. the enthalpy flow, as the cooling performance representative of thepulse tube, reaches maximum for an optimum convergent taper angle. the temperature distribution andheat transfer process along the axial direction, as well as the phase behavior of the heat transfer coefficient,are also studied. it is shown that, moving from the cold to the hot end of the pulse tube, the temperaturevariation domain and heat transfer rate decrease.