FLOW THROUGH SCREENS

The wider engineering application of screens cannot be covered completely here, and no more than a few examples with pertinent references can be included. Gauze screens have been used in diffusers to reduce flow separation and produce uniform exit flows (Schubauer & Spangenburg 1948). With a gauze screen in conjunction with a diffuser of specified wall design, wide-angle diffusion in a short overall length with little separation and uniform outlet profile is possible (Gibson 1959, Kachhara et al 1976). Gibbins (1973) has designed a pyramid gauze diffuser. Carefully positioned screens in jet engines have been used as effective noise reduction devices (Callaghan & Coles 1955). Aerodynamically designed sails (Barakat 1964) and fishing nets (Morgan 1966) are similar applications of the screen (porous sheet), as is the design of shaped filter bodies serving the dual role of flow conditioners.