Optimization and determination of the frequency response of constant-temperature hot-wire anemometers

Recent findings that the common practice of optimizing the frequency response of constant-temperature hot-wire anemometers usingasquare wave test may resultinthe system being strongly underdamped have been confirmed. An iterative method based onthe energy spectra of the responsesto the square-wave perturbations is proposedto achieve an optimal frequency response. The frequency responses at different operating conditions determined from the new and traditional methods are compared to show that the new optimization method can greatly improve the flatness of the frequency response of the constant-temperature hot-wire anemometer for all the operating conditions. It is also found that the constant-temperature hot-wire anemometer respond differently to the rising and falling edges of the square-wave perturbations due to nonlinearity, and this nonlinearity increases with the overheating ratio.