Base pressure prediction in bluff-body potential-flow models (Q2702876)

In a recent study by the authors [ibid. 333, 403-413 (1997; Zbl 0896.76005)], a wake width was proposed which allowed to extend the bluff-body potential-flow model by \textit{G. V. Parkinson} and \textit{T. Jandali} [ibid. 40, 577-594 (1970; Zbl 0185.54107)] to include the flow around an oblique flat plate. By incorporating this wake width in the momentum equation originally derived by \textit{R. Eppler} [Z. Flugwiss. Weltraumforsch. 11, 133-144 (1987; Zbl 0619.76015)]{} for separated flow, the drag of the plate was related through a simple analytical condition to its inclination and to the base pressure. The method allowed the base pressure, which is usually treated as an empirical input, to be determined theoretically, and thus the model became self-contained. Based on such a wake width and the separation velocity deduced from base pressure measurements, the authors found that the modified Strouhal number is independent of the inclination. NEWLINENEWLINENEWLINEThe purpose of this study is to demonstrate how this wake-source model can be used to provide another relationships among the drag, base pressure and inclination. As a result, the base pressure is simply found by solving simultaneously a system of nonlinear algebraic equations at any particular inclination. The results show that the predicted base pressure, drag and wake width agree reasonably well with experimental data for the inclined flat plate and with measurements for the wedge of arbitrary vertex angle. This relationship, when incorporated in free-streamline models available in the literature, produces similar good agreements.