Investigation of air-water two phase flow through a venturi

Study of two phase flow characteristics is of prime importance in various modern engineering fields including nuclear. In a 700 MWe Indian Pressurized Heavy Water Reactor (PHWR), limited boiling is allowed in the channels to extract more power. In this pressure tube type of reactor, the channel power computation requires the measured channel flow and outlet quality. Though the channel flow-rate can be measured at the inlet feeder to the reactor core, the channel outlet quality needs to be derived from the measured two phase pressure drop across a venturi located at the outlet feeder of the same channel. The measured pressure drop shall be correlated to the mixture density of two phase steam-water flow in the channel. In order to study the pressure drop characteristics of the specific venturi under two phase conditions, an experimental study was performed with air-water two phase flow, with same the venturi channel system as that in the prototype reactor. A series of tests were carried out by varying the air/water flow rates, in a multiphase loop. The pressure drop across the venturi was measured using a DPT (Differential Pressure Transmitter). The measured data was compared with the correlations available in literature.