Pages 51-52
The jet expands outside the nozzle exit when the injection pressure is much larger than the ambient one. The jet flows as an underexpanded flow. The behavior of underexpanded jets injected into the atmospheric pressure ambient are well known. However there are few works about the flow at high pressure ambient. Therefore in this study, the jet flows near the nozzle exit have been observed with changing experimental conditions of injection, ambient gas, and nozzle configuration to clarify their effects on structures of underexpanded jets and on the jet developing process.
