Journal of Xi'an Jiaotong University

Theoretical and Experimental Investigation on Natural Frequency of Compressor for Stirling Cryocooler
Liu Dongyu¹，Wu Yinong¹，Wang Weiyang¹，Chen Chunzheng²
（1.Department of Cryogenics，Shanghai Institute of Technological Physics，Chinese Academy of Sciences，　Shanghai　200083，China；2.Institute of Refrigeration and Cryogenic Engineering，Xi'an　Jiaotong　University，Xi'an 710049，China）

Abstract：A new calculation formula for natural frequency of compressors with higher accuracy was presented． The idea and method of deducing this formula were described in detail．A kinematic equation for pistons was established based on analyzing forces，in particular， gas force acting on the piston． The acting mechanism and physical meaning of gas force were stated by means of rotation vector decomposition．The Helium gas in compression space was regarded as gas spring and compression power absorber．Consequently， the calculation formulae for stiffness and natural frequency of the compressor were developed．The accuracy of this formula was verified by an experimental test on a 2 W@80 K split stirling cryocooler．The results calculated with the present formula was more consistent with experimental data compared with other existing formulae．Moreover，the theoretical analysis of gas force was confirmed by the different compressor load test．
Keywords：stirling cryocooler；compressor；natural frequency