module (Fig. 9.28) is one of the several types of rigid module outlet.
It has a semicircular eddy chamber in plan, connected by a rising
inlet pipe. A free vortex flow is developed within the inlet pipe, thus
creating a rise in the water level at the outer circumference of the
eddy chamber (since Vrconstant for free vortex flow). The exces-
sive energy of the entering flow (due to the increase in the head
causing the flow) is dissipated by the baffle walls supported from the
roof, thereby keeping the discharge constant over a wide range ofINTAKES 403
Fig. 9.26 Open flume type farm outlet (India and Pakistan)
Fig. 9.27 Adjustable orifice semi-module (AOSM). Plan layout to conform
to the open flume type (Fig. 9.26). H/D0.3 for proportional outlet