VERIFICATION OF A HIGH-ACCURACY DIVERSION CHAMBER USING COMPUTATIONAL FLUID DYNAMICS

Abstract

 The accuracy of the diversion control of a high-accuracy diversion chamber, which can draw a certain flow rate from an unsteady open channel flow, was verified by computational fluid dynamics (CFD). First, we conducted a numerical simulation of an existing laboratory experiment to confirm the validity of the CFD. The accuracy of the diverted flow rate simulated by CFD was estimated to be equivalent to that by the experimental measurement. Next, we simulated 3 cases with different numbers and arrangements of orifice holes in the general design of a high-accuracy diversion chamber that is expected to be applied to a combined sewer system. In the case of a single orifice hole, it was difficult to control the diversion due to the effect of the jet flow from the orifice hole. On the other hand, in the case with multiple orifice holes, the effect of the jet flow was sufficiently mitigated. Besides, it was found that a high-accuracy diversion chamber allows for much more accurate diversion control compared to the conventional diversion chamber.