it would seem that a wedge oulet matching the web inlet would be beneficial. richard

Well I don't think so. The output duct (if any) of a wedge fed core  should be as unobstructed as possible.

Do you you have my book?

Kuchemann and Weber studied the problem extensively some of which is inb my book. ANY obstruction behind the core will have a certain dynamic pressure develop on it which will negate some of the pressure on the front of the core. What you are looking for is a uniform pressure drop across the core. The higher the porosity of the core the lower the pressure drop and the lower the cooling drag.

Paul Lamar