On Calculation of Induced Drag and Conditions Downstream of a Lifting Wing

Abstract

Results Figures 3 and 4 illustrate the plot of the velocity maxi- ma predicted by the above method compared with the measurements of Schauer and Eustis.6 The nondimen- sional static pressure on the bottom wall is also calculated by using Bernoulli's theorem. p + 1/2 pw2 = const on a streamline. The agreement with the experiments of Refs. 3 and 6 is good for the measured static pressure dis- tribution. It is also seen from the above graphs that a nondimensional profile could be obtained for various nozzle distances. The computing time involved in the above calculations were of the order of 5 sees. The bound- ary layer close to the wall could be described by a Bound- ary layer type approximation with a velocity at the outer edge given by the velocity distribution on the bottom plate. Conclusions Considering the normal impinging jet flow as consisting of two different regimes an expeditive method of calcula- tion has been developed. The present method takes into account the viscosity effects producing a rotation in the flow, and also it requires an incomparably shorter com- puter time than needed for the solution of the full Navier- Stokes equation. The accuracy of the predictions by using this method is as good as the predictions assumed by more time consuming methods.