Flow measurement and instrumentation flow control characteristics of throttling venturi valve with adjustable area

In this study, a throttling venturi valve with adjustable area was designed to control the thrust of a mono propellant thruster using hydrogen peroxide. The flow rate control characteristics of the throttling venturi valve were investigated based on the pintle stroke and upstream pressure of the venturi. Three kinds of experiments were conducted: pressure and flow rate measurement according to pintle stroke and venturi upstream pressure, determination of critical pressure ratios under various conditions, flow rate control performance through open loop control and feedback control of an actuator. The pressures were measured at the upstream, throat, and downstream of the venturi. It was observed that the flow rate changed in proportion to the stroke and upstream pressure. Below a stroke of 10 mm, the critical pressure ratio gradually decreased as the stroke and upstream decreased. However, above a stroke of 10 mm, the critical pressure ratio converged to a value between 0.7 and 0.8 regardless of the upstream pressure. The results of automatic flow rate control tests using open-loop control and feedback control showed that the measured flow rate satisfactorily followed the target flow rate profile.

Automated summary

The study found that the flow control of the throttling venturi valve is influenced by the pintle stroke and upstream pressure, with the critical pressure ratio converging within a certain range. In flow control tests, the measured flow rate satisfactorily followed the target flow rate profile.