2009 Volume 3 Issue 1 Pages 289-300
One of the most interesting devices for light water reactor systems aimed at simplified system, improvement of safety and reliability is a supersonic steam injector. Supersonic steam injector is a passive jet pump without rotating machine and high efficient heat exchanger because of direct contact condensation between supersonic steam and a subcooled water jet. It is considered that flow behavior in the supersonic steam injector is related to complicated turbulent flow with large shear stress induced by velocity difference between steam and water and direct contact condensation. However, studies about turbulent flow under large shear stress with direct contact condensation are not enough. Especially, mechanisms of momentum and heat transfer are not clarified in detail. Objective of the present study is to investigate turbulent behaviors of a water jet and interface that play an important role in heat transfer and momentum transfer. Radial distribution of streamwise velocity and fluctuation of total pressure are measured by a pitot measurement. Visual measurement of the turbulent water jet is conducted by a high speed camera in order to identify location of unstable interface and its behavior. It is found that streamwise velocity increases as it approaches downstream of the mixing nozzle. Fluctuation of total pressure is large at water-steam mixture region. It is confirmed that waves propagated on the interface. And its velocity is obtained.
