The Discharge Coefficient of a Planar Submerged Slit-Jet

Abstract

The discharge coefficient, CD, of a planar, submerged slit-jet has been determined experimentally over a relatively wide range of Reynolds number values: Re=100–6500, where the slit width (w) and the average streamwise velocity (〈U〉) at the exit plane are used to define the Reynolds number. The CD values exhibit a strong dependence on Re for Re<800. For Re>3000,CD achieves an apparent asymptotic value of 0.687 for the present nozzle design. This value is about 12% higher than the potential flow value. In contrast, the velocity distribution along the centerline was in excellent agreement with that of the potential flow solution. The experimental techniques that were used to evaluate the CD(Re) values, their numerical values, the corresponding uncertainties, and the possible influence of the geometrical design of the nozzle on the results are presented.