Measurement of Instantaneous Fluid Temperature and Two Fluid Velocity Components Using Hot-Wire Anemometers

Hot-wire anemometers, when used in a nonisothermal flow field, respond to both fluid temperature and fluid velocity fluctuations, even when operating conditions are selected to minimize the response to one of the stimuli. Use of a two-or three-wire array for the simultaneous measurement of temperature and velocity fluctuations and their mutual statistics has been shown to lead to significant errors, if, as is general practice, the approximate sensor responses are assumed to be ideal responses. An extension of the traditional techniques is described which eliminates this major source of error but still retains the simplicity of signal processing of the earlier methods.