Effect of exit-port geometry on the performance of a flow distribution manifold

A significant issue of manifold design, not heretofore considered, is the geometric shape of the exit ports as a means for tailoring manifold performance. To investigate the efficacy of this strategy, three candidate exit-port geometries were considered: (a) an array of discrete slots, (b) an array of discrete circular apertures, and (c) a single, continuous longitudinal slot. In order to have a valid comparison of the impacts of these individual geometries, the total exit areas of all three were made identical. Numerical simulations of the turbulent flow within and exiting from these manifolds were performed using a turbulence model that had been previously established by comparison studies involving both simulations and experiments for situations related to that considered here. The numerical results indicated that the continuous single-slot geometry yielded the most uniform outflow from among those considered. With regard to practice the simplicity of manufacture of single-slot-equipped manifold has clear advantages.