PREDICTION OF NATURAL FREQUENCY OF THE NASA 80 K COOLER BY THE STIRLING REFRIGERATOR PERFORMANCE-MODEL

A computer model known as the Stirling refrigerator performance model (SRPM) has been developed to study Stirling refrigerators. A detailed description of this model can be found elsewhere. Excellent agreement was found between the predictions of the SRPM and the experimental res ults for a number of Stirling coolers, including Lucas coolers, a Phil ips/NASA magnetic bearing unit, Oxford refrigerators and the Lockheed/ Lucas built Atmospheric Infrared Sounder (AIRS) coolers, units A, B an d C. In this paper, the performance of the NASA 80 K cooler, as predic ted by the SRPM model, is presented. In particular, the prediction of the natural frequency and the motor force will be discussed in detail.