Author: Robert Leigh Underwood

Publisher:

Published: 1968

Total Pages: 112

ISBN-13:

An accurate description of the flow field about a cylinder is found possible with a semi-analytical solution of the full Navier-Stokes equations. The method of series truncation is employed to reduce the governing partial differential equations of motion to a system of ordinary differential equations which can be integrated numerically. This method, which has been applied to the hypersonic blunt-body problem by previous investigators with great success, is essentially a successive-approximation procedure which treats an elliptic partial differential equation as if it were parabolic or hyperbolic. The dependent variable is expanded in one co-ordinate, and backward influence in the resultant system of ordinary differential equations is prevented by series curtailment. Results are given for Reynolds numbers between 0.4 and 10.0 (based on diameter); however, the method can be applied to both higher and lower Reynolds numbers without modification. An accurate prediction of the Reynolds number at which separation first occurs behind the circular cylinder is made; this separation Reynolds number is found to be 5.75. Over the entire Reynolds-number range investigated, characteristic flow parameters such as the drag coefficient, pressure coefficient, standing-eddy length, and streamline pattern compare favorably with available experimental data and numerical-solution results. It is concluded that the semi-analytical method of series truncation permits accurate determination of the flow field about a circular cylinder at moderate Reynolds numbers without resorting either to full-numerical solution or to experiment. (Author).