Some factors affecting the metering of subcooled water with a choked venturi

A series of experiments characterizing the subcooled choking process in a convergent-divergent nozzle with a constant area throat is described. A low pressure flow loop capable of a maximum water flow rate of 5.5 L/s with a pressure head of 300 kPa and the pressure and temperature upstream of the nozzle in the flow loop adjusted between 90 and 300 kPa and 53 and 96 C. The flow rate, upstream pressure and temperature, and the axial wall pressure profiles in the nozzle were measured. Critical mass flow rate data were acquired along five isotherms as a function of stagnation pressure. Factors affecting metering performance are examined.