Effects of Gas Flow Rate on Powder Supplying Characteristics under the Action of Moving Wall

Abstract

The fluidization and transportation characteristics of powder fuel is a key to the design of fuel supply system of powder engine. In order to deeply study the fluidization characteristics of powder fuel, a numerical simulation method based on the two fluid model for dense gas-solid is built, which considers the action of moving wall through user defined function(UDF), and the influence of gas flow rate on the fluidization and characteristics of powder fuel are analyzed numerically. The results show that in the start-up stage, the powder mass flow rate entrained by fluidized gas under different cases is greater than theoretical flow rate, the pressure in powder storage tank and the force on moving wall are greater than that in steady stage, and the particle output and powder storage tank pressure increase with the increase of fluidized gas flow rate.In steady stage, the mass flow rate of powder pushed forward by the moving wall and the powder mass flow rate entrained by fluidized gas reach a dynamic balance. A relatively stable gas-solid interface can be formed under different cases, and the average powder flow rate is less than the theoretical flow rate. The average powder flow rate increases with the increase of fluidized gas flow rate, and the height of powder bed decreases with the increase of fluidized gas flow rate.

Keywords

• |powder engine|two fluid model(tfm)|dense two-phase flow|mass flow rate|fluidization process|piston movement