The Structure of Wall-Impinging Jets: Computed Versus Theoretical and Measured Results

In this work, the structure of computed wall-impinging gas jets is compared with theoretical and experimental results presented in the literature. The computational study employs the k-ε model to represent turbulence. Wall functions are employed to model momentum transfer at the walls. The computed penetration and growth rate of the jet agree with measured and analytical results within 10%. Computed radial velocities in the developed region of the wall jet are self-similar as found in prior experimental and analytical works. The computed radial velocity profile and quantitative values in the outer layer of the jet and the location of the maximum radial velocity agree within 5% with measurements and analytical results. Greater quantitative differences are found in the near-wall region. Mixing characteristics of a wall-impinging jet are compared with those of a round free jet. The wall-impinging jet mixes slower than the round free jet.