The velocity field of a circular jet in a counterflow

This paper describes an analysis of the velocity field of a circular jet in a counter flow. The treatment is based on the relative motion and momentum criteria. Starting from our previously derived Chan-Lam Equation for the centreline velocity decay, the spreading of the jet in the counterflow is computed with the assumption of conserved momentum and Gaussian distribution in the radial direction of mean flow velocities. Expressions for the jet widths and radial velocity profiles are obtained. The mean velocity fields at a number of jet-to-current velocity ratios are measured in the laboratory with laser-doppler anemometry (LDA) and the results compare well with the analytical expression.