Abstract: Abstract：To explore a convenient expression of gas flow in the thrust chamber of space rocket engine, the similarity analysis of gas flow in the thrust chamber is carried out. Firstly, a numerical model is built to describe the gas flow in the thrust chamber, and the gas flow velocity and pressure are calculated under typical structure and operating conditions. Secondly, the similarity criteria of gas flow are derived based on dimensional analysis. The dimensionless expression method of gas flow velocity and pressure in thrust chamber is promoted with the similarity criteria. Then the numerical calculation under various structure and operating parameters is organized with an orthogonal design plan. Lastly, the dimensionless expression of gas flow velocity and pressure is obtained with the numerical results as input.  

Key words: Keywords：space rocket engine, combustion chamber, gas flow, numerical model, similarity criteria