Methods based on one component Laser Doppler Anemometer and Hot Film Anemometer for three dimensional turbulent measurements.

In the present study, an experimental investigation is conducted for the research of the turbulent open channel flow field at the three directions with the aid of one component Laser Doppler Anemometer and x Hot Film sensors. The instrumentation is used in an efficient manner for the extraction of three turbulent statistics with one measurement. The application of the present technique is conducted on fully developed uniform open channel turbulent flow and on flow with suction from the bed. With the aid of assumption for zero correlation between velocity and direction fluctuations the required number of measurements in the plane of flow direction for turbulent statistics is reduced. Using the Hot film sensor in the streamwise- spanwise orientation and with the LDA beam plane inclined in streamwise - vertical plane for the extraction a component of streamwise velocity direction, the three turbulent statistics are estimated. Also, with the assumption of randomness of velocity fluctuations of the open channel flow in the zero correlation assumption, the dependence of turbulent statistics with the angle is possible to be calculated. The influence of suction from the bed on the uniform open channel flow, alters the turbulent flow field characteristics and in the present paper the distribution of turbulent intensities are presented for various suction rates in the flow depth. In the form of covariance and autocovariance, angle dependence is examined for uniform flow and for flow with suction from the bed.