A hot-wire measurement technique for complex turbulent flows

A hot-wire technique is described which can be used to measure all three components of the local mean velocity vector and all six components of the Reynolds stress tensor in a low-intensity turbulent flow which is arbitrarily skewed in pitch and yaw by as much as 30 degrees. The technique is based on positioning a slant wire in certain planes (designated as optimum planes) where the wire is sensitive, st most, to only two of three mutually perpendicular fluctuation components. Results based on data obtained in fully-developed turbulent pipe flow under simulated skewed flow conditions demonstrate the validity of the technique. Comparisons show that the present method is superior to a conventional method based on probe rotation in fixed angular increments when the flow is moderatelyto-highly skewed.