Study on Circular Jet Issuing along Cylinder or Pipe Wall

Please try later.

The circular jet which issues along the outer wall and in the longitudinal direction of the cylinder has been investigated in this paper. Especially, attention is focussed on the unsteady structure of the flow field where the wall jet separates at the down stream location far form the exit. In order to reveal this unsteady property the wavelet analysis was used. In addition to some ordinary wavelet correlations, the wavelet intermittency was newly introduced Though these wavelet analytic methods the separated flow has been clarified The obtained conclusions as follows.(1) From the results of flatness factor and intermittency factor, the intermittency of the flow appears in outer edge of the jet. This intermittency seems to correspond to the separating flow besides the rolling up flow.(2) In order to reveal the unsteadiness of flow, some wavelet analysis were introduced. From the results of the wavelet transfrom and wavelet auto-correlation, it has been clarified the flow field in the downstream location is unsteady considerably.(3) From the results of wavelet cross-correlation by using two sensors, the large scale structure is seen to pass and grow up.