Experimental investigation of turbulence intensity measurement in continuous transonic wind tunnel

The constant temperature anemometer is used for turbulence intensity measurement from the entrance of the heat exchanger to the test section in a 0.6 m continuous transonic wind tunnel. Two dimensional hot wire probes were rotated to measure the three dimensional turbulence intensity in the flow field from the entrance of the heat exchanger to the exit of the setting chamber. One dimension hot wire probes were used for turbulence intensity measurement in transonic flow of test section, with the method of continuous varying hot wires over heating ratio, where the maximum testing flow velocity was Ma1.5. Test results show that, the heat exchanger and the setting chamber paly important roles in damping turbulence intensity, each of which could reduce the turbulence intensity by more than 90%; when the screens in the setting chamber are added from 3 to 5 layers, the turbulence intensity of setting chamber could be decreased by 50%, and could be decreased by 17% in the test section; using the continuous varying hot wires over heating ratio method, the fluctuation diagrams and turbulence intensity are acquired in the test section. The fluctuation curve is of the straight line type at Mach number 0.4, and the fluctuation curve is of the hyperbola type at Mach number 0.7, which present the fluctuation characteristics in the flow field. Experiment results are useful for flow turbulence evaluation and optimization in the continuous transonic wind tunnel.