Research On Flow Properties And Thermodynamic Characteristics Of Laval-type High Temperature Flow Rate Control Valve

It is a key technology to control the fuel flow accurately for the Scramjetengines. When the fuel passes into the engine combustor, its’ temperature will reachto800-1000K because of the active cooling method. In order to control the flow rateof fuel at high temperatures, it is of great significance to study the high temperaturecontrol technology with the control valve. Researches on this area are all based onlow temperature. They cannot meet the control conditions and response the speedtechnical requirements.This paper studies a kind of high temperature valve based on the characteristicof the Laval nozzle, with which can be used to obtain a steady mass flow with a lowpressure loss. It is a kind of pilot control valve with an actuating piston, which candrive the spool. With this method we can control the flow of high temperature valve.Both the research on the flow properties and thermodynamics characteristics onthe research of the Laval-type high temperature control valve are carried. Throughthe mathematical modeling and analyzing by CFD software such as Fluent、ANSYSCFX and ANSYS Workbench, we have obtained the properties of flow andthermodynamics of the high temperature control valve in different conditions. Thehigh temperature properties and the thermal stress can be researched on with themethod of heat-flow coupling and fluid-solid coupling. It provides the theoreticalbasis for the material selection of our high temperrature control valve by comparing45#steel and GH783alloy.Experiments research on this area on the purpose of achieving our goal both onflow controlling accurately and high temperature distribution are studied.Experiments both at normal temperature and another at high temperature for the flowrate control valve are carried out. Through both of them we obtain useful results,such as diagram of mass flow in different inlet pressure and distribution of the valveat high temperature. It is necessary to have the simulation research through thecomparison of experiments’ results and simulation results. The flow characteristics ofhigh temperature valve indicate that we can obtain a steady mass flow with a lowpressure loss using the Laval nozzle structure outlet valve; and the valve bodythermodynamics properties indicate that the design of valve body meet therequirements.