Pressure Measurements in Jets Diffusion using a Developed Hot-Wire Static Pressure Sensor

Abstract

The aim of this experimental study is to investigate the diffusion of jets, with particular attention focused on the relationship between the static pressure and the stream wise mean velocity on the development of a two-dimensional air jet. A jet with three injection velocities (11.7, 23.3 and 35.0 m/s) was generated in a two-dimensional wind tunnel. The velocity distributions were measured by an X-type hot-wire anemometer. The static pressure distributions were measured by a static pressure probe developed in our laboratory, which incorporates a hot-wire anemometer. The probe is designed to be able to measure the mean static pressure and pressure fluctuation simultaneously. The sensitivity is 92.3 mV/Pa. The frequency response is flat from 16 Hz to 2.5 kHz. As a result of the experiment, it was found that negative static pressure exists in the turbulent shear layer. It is considered that the entrainment process from the negative static pressure by the vortex structure motion of the turbulent shear layer.