Journal of Thermal Science

, 8:79

First online:

Navier-Stokes computations of the supersonic ejector-diffuser system with a second throat

  • Heuy-Dong KimAffiliated withSchool of Mechanical Engineering, Andong National University 388
  • , Toshiaki SetoguchiAffiliated withDepartment of Mechanical Engineering, Saga University 1
  • , Shen YuAffiliated withInstitute of Engineering Thermophysics, Chinese Academy of Sciences
  • , S. RaghunathanAffiliated withDepartment of Aeronautical Engineering, The Queen’s University of Belfast

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The supersonic ejector-diffuser system with a second throat was simulated using CFD. An explicit finite volume scheme was applied to solve two-dimensional Navier-Stokes equations with standard k – ε turbulence model. The vacuum performance of the supersonic ejector-diffuser system was investigated by changing the ejector throat area ratio and the operating pressure ratio. Two convergent-divergent nozzles with design Mach number of 2.11 and 3.41 were selected to give the supersonic operation of the ejector-diffuser system. The presence of a second throat strongly affected the shock wave structure inside the mixing tube as well as the spreading of the under-expanded jet discharging from the primary nozzle. There were optimum values of the operating pressure ratio and ejector throat area ratio for the vacuum performance of the system to maximize.


compressible flow supersonic ejector supersonic diffuser internal flow shock wave turbulent mixing