Three-dimensional turbulent flows of a distribution manifold are studied by turbulence models. It is difficult to introduce real manifolds of various systems. So, to investigate the geometrical effects, a simplified manifold is adopted. The exit configuration depending on the departure angle has advantages to the outflow uniformity. Also the decreased exit area in the streamwise direction improves the uniformity of exit flow. However, for the uniform effusion, the change of exit port by departure angle is more effective them the change of exit area.