TAPPI TIP 0410-02:2004

The primary variables which govern the angle of outflow and contraction coefficient for a vertical slice are shown in Fig. 1. The depth B may be to a free surface or to a rigid boundary. If this upper boundary is inclined, the angle of inclination may influence the outflow if the ratio b/B is near unity. Fig. 2 shows the angle of outflow, , as a function of the relative bottom lip extension and the geometric ratio b/B. Fig. 3 is a companion chart for determining the contraction coefficient. Fig. 4 provides a comparison between the theoretical angle of outflow and data reported from laboratory experiments. The information presented in Figs. 2 and 3 was derived for a nonviscous, ideal fluid and can be used to predict high velocity outflows of dilute fiber suspensions in water, provided that the effects of gravity and surface tension are small and the flow is unobstructed for a distance of several times the slice opening b.