Abstract
The use of generalized functions to analyse the potential, two-dimensional, incompressible flow past singularities representing stationary and moving lifting lines is explained and developed. It is shown that the time mean stagnation pressure change in the flow through a moving cascade with fluctuating lift is normally zero, except when the lift fluctuations are in phase with the motion, so that a stationary system of shed vortices is produced in the downstream flow (the stationary, phased, fluctuating lift case). Then the time mean stagnation pressure is a function of position in the absolute co-ordinate system.
Expressions are obtained for the kinetic energy produced by the vortices shed off a row of blades with fluctuating lift. Idealized losses or drags due to these effects may amount to ½ or 1 per cent of the work or lift effects produced by the cascade.
Get full access to this article
View all access options for this article.