Abstract: The flow field,in decompression of the lab-built rapid decompression simulator,was empirically approximated with compressible gas,mathematically formulated with standard k-ε model,theoretically analyzed in 1-D steady isentropic flow theory,numerically simulated in finite element method with Fluent software and experimentally evaluated.The influence of the key variables,including,but not limited to the volumes and pressures of the decompression chamber and sub-atmospheric pressure tank,thickness and area of the blasting glass window,on the time evolution of the flow field in rapid decompression,including the distributions of pressure and velocity,was investigated for design optimization.The calculated and simulated results show that the newly-developed rapid-decompression simulator meets the stringent design requirements,for example,the decompression can be regularly and rapidly achieved in 10 ms.The measured,calculated and simulated results were found to be in good agreement.