Hot-wire based estimation of pressure fluctuations in the near field of a jet in the presence of a co-flow

It is shown that the velocity fluctuation spectra measured using a hot-wire in the potential flow region of a turbulent jet near field in the presence of a co-flow can be converted into the spectra of pressure fluctuations. The proposed conversion method is based on the fact that the structure of instability waves, which make a decisive contribution to the jet near-field fluctuations, resembles homogeneous one-dimensional waves, which makes it possible to locally link the pressure fluctuations and the fluctuations of the streamwise velocity component measured by a hot-wire.