DOI: 10.1615/ICHMT.2009.TurbulHeatMassTransf
ISBN Print: 978-1-56700-262-1
ISSN: 2377-2816
An experimental study of a plane turbulent wall jet using LDA
Краткое описание
An experimental investigation using laser Doppler anemometry was conducted of the mean flow characteristics of a turbulent wall jet on a smooth surface. The Reynolds number based on the slot height and exit velocity of the jet was Re ≈ 7,400. Measurements were carried out at downstream distances from the jet exit ranging from 20 to 80 slot heights. Conventional scaling, momentum-viscosity scaling and wall-jet similarity theory were used to analyze the streamwise evolution of the flow. Mean velocity profiles in both outer and inner coordinates are presented in this paper. Using conventional scaling, the mean velocity profiles were self-similar in the developed region of the jet and the jet spread rate was linear. Fitting to velocity profiles in inner coordinates indicated that use of a power law provides accurate and consistent estimates of the friction velocity in a plane turbulent wall jet. Both the spread rate and the maximum velocity decay were analyzed using different scaling laws. The power law constants in the present work differ from those in other studies which illustrates the sensitivity of the constants to the initial conditions. Skin friction coefficients in the present work showed good agreement with the results of other correlations and experimental studies.