Study on Coaxial Double Pipe Air Jets at Different Temperatures.

Abstract

A study on coaxial double pipe jets at different temperatures has been carried out with mean velocity ratios of inner pipe jet to annulus jet from 1.0 to 3.0. The radial distributions of the local mean velocities and the fluctuating intensities of velocity (axial turbulence intensities) in isothermal air jets (Pra0.7) were measured at various axial distances of up to twenty times the pipe diameter downstream. Measurements were also made of the radial distributions of the local mean temperature and the fluctuating intensities of temperature in nonisothermal jets. The profiles of velocity in relation to those of temperature are described in detail in the developing region of coaxial jets. Moreover, the fluctuating intensities of velocity are compared with those of temperature.