The Improvement of the Combined Probe for the Simultaneous Measurement of Instantaneous Static Pressure and Two Velocity Components and the Estimation of Turbulent Energy Transport in the Two-Dimensional Jet(Fluids Engineering)

Abstract

The new combined probe for the simultaneous measurement of instantaneous static pressure and two velocity components is developed. The probe consists of X-type hot-wire, and newly-devised static pressure probe. The pressure probe is miniaturized by using 0.1 inch microphone and MEMS fabrication technique for the improvement of spatial resolution and it is placed between two hot-wire sensors. The tip shape of the static pressure probe is hemispherical like the pitot tube also for the miniaturization of the combined probe. The spatial arrangement of pressure probe and X-wires in the new combined probe is determined carefully so that there is no interference in the velocity and pressure statistics measured by each sensor. The simultaneous measurement of instantaneous two velocity components and static pressure is carried out in the two-dimensional turbulent jet by this new combined probe. The results show that the distributions of mean streamwise velocity U and fluctuating velocity u, v and pressure p are consistent with the previous work. Furthermore, the turbulent energy budget is estimated. It is shown that the integral value of diffusion term (that should be equal to zero in theory) is closer to zero than the previously reported result by the measuring of diffusion rate <vw^2>^^^- in the diffusion term.