Development of a probe for measuring turbulence in three dimensional flows.

A new hot wire technique was developed and used for the simultaneous measurement of the three instantaneous velocity components in a turbulent swirling jet issuing into a coflowing stream. The probe includes four wires slanted at 45DEGREES in a double vee funnel configuration. Each vee funnel shaped is perpendicular to the other. A fully developed turbulent pipe flow, at Reynolds number (Re) of 50,000, was measured to evaluate the overall performance of the four wire system. Measurements were carried out at various radial locations 138 pipe diameters downstream from the entrance. This data obtained is compared with the classical results of Laufer (1954) and with the measurements of Wyganski and Champagne (1973) taken at an identical Re. New information concerning the distribution of the UW Reynolds stress product in the pipe flow is presented. Measurements at several axial locations in a turbulent swirling jet issuing into a coflowing stream were conducted. The swirl number and the velocity ratio were 0.265 and 0.2 respectively. At each axial location, the radial survey covered both sides of the centre line. Some of these results are compared with measurements of Samet which were obtained under similar flow conditions and at the same flow facility with a precalibrated directional sensitive five tube pressure probe.