A finite volume method to investigate flow characteristics of an orifice pulse tube refrigerator

A finite volume method is developed for simulation of oscillatory compressible flow in the pulse tube part of an orifice pulse tube refrigerator. Governing equations for control volumes are written in 1D discretized form. Second order upwind is used for the convective terms as well as Euler implicit method for temporal derivatives. The results include the temperature and mass flow rate as functions of time and position, and the buffer pressure as a function of time. A typical pulse tube is modeled by using the numerical model. The results show that the present numerical method has good agreement with previously published results. The cold end (inlet) mass flow rate makes an angle of 39.60 with the pressure vector. Hot end mass flow rate is in phase with the pressure vector. Previously, it was mentioned that in one-dimensional models, overshoots never disappear completely, whereas in the present one-dimensional model they are eliminated. The overshoots in the both ends for present results are less than those for 3D results. By using the results of Eulerian coordinate, Lagrangian approach is used to track the movement of the gas parcels to get their pressure, temperature, and velocity in a thermodynamic cycle.