A 2-DIMENSIONAL MODEL OF THE FLUID-DYNAMICS OF AN AIR REVERSER

A theoretical analysis of the fluid mechanics of the air cushion of th e air reversers used in web-handling systems is presented. A two-dimen sional model of the airflow is derived by averaging the equations of c onservation of mass and momentum over the clearance between the web an d the reverser. The resulting equations are Euler's equations with non linear source terms representing the air supply holes in the surface o f the reverser. The equations are solved analytically for the one-dime nsional case and numerically for the two-dimensional case. Results are compared with an empirical formula and the one-dimensional air-jet th eory developed for hovercraft. Conditions that maximize the air pressu re supporting the web are analyzed and design guidelines are deduced.