The Effect of the Air Humidity on the Cascade Performance in the Suction Type Shock Tunnel

Abstract

The effects of water vapor condensation on the transonic turbine cascade flow in a suction type shock tunnel are investigated by the optical methods and by the wake traverse method using the Pitot comb with silicon oil containing tubes. It is shown that the flow pattern and the downstream total pressures are influenced considerably by the condensation for the supersonic exit flow. The traverse test results using the shock tunnel with dried air (Dew point T_d=-10°C) show fairly good agreement with the experimental results in an ordinary blow-down type wind tunnel, which are considered to have almost no effects of water vapor condensation.