An Improved Model of Free Piston Compressor Considering Entropy Change
摘要
Free piston compressors are widely used in wind tunnel facilities. Researchers from different countries have been making efforts to predict the flow in free piston compressors theoretically or theoretically. A 1D simulation program is developed to simulate the operation of the free piston compressor in FD-21 shock tunnel, which shows great agreement with experimental pressure profiles. Flow structure and characteristics of the compressed premixed gas in the compression tube are discussed; Based on simulation results under varied flow conditions, the non-isentropic phenomena including shock wave and heat transfer of the compressed gas are revealed and characterized. An improved model of free piston compressor considering entropy change is developed, which will be helpful in the improvement of corresponding test facilities.