The offset angle of gas wave refrigerator is one of the most important parameters affecting the refrigeration efficiency. In this study

the optimal offset angle corresponding to the opening state of oscillating tube is analyzed by numerical methods. The numerical results

theoretical calculations and experiments are combined to explore the method for predicting the optimal offset angle and analyze the influence of offset angle on the refrigeration efficiency. Under given condition

when the shock wave reaches the end of the oscillating tube and half of the tube is contacted with the high temperature port at the same time

the offset angle of gas wave refrigeration is the optimal. The optimal offset angles determined by experimental data have the same trends with theoretical calculations

increasing with the angle and rotation speed

but the values differ considerably from the theoretical results. The optimal offset angles calculated by numerical simulation agree well with the experimental results

with the error less than 1%. When the rotation speed of gas wave refrigeration is lower than that with the optimal offset angle

the refrigeration efficiency decreases linearly with the reduction of rotation speed. When the rotation speed is faster than that speed

the refrigeration efficiency increases linearly with the reduction of rotation speed. With the change of rotation speed

the absolute values of linear fitting curve slope of rising and falling of the refrigeration efficiency is almost equal

which lies in the range of 0.009—0.012.