Structural parameters of pintle on transcritical combustion efficiency of liquid oxygen/methane engine

To study the effects of pintle structural parameters on the combustion efficiency in transcritical combustion， a standard k-Ε turbulence model and a non-adiabatic stable diffusion flamelet model were utilized to numerically study the transcritical combustion of an LOX/CH4 pintle engine considering the real gas properties of fluid. The study analyzed the impact of various methods for calculating physical properties on the flow field within the thrust chamber， and the effects of radial and axial annular seam width of pintle injector on engine combustion efficiency were analyzed. The results showed that the size of both the central recirculation zone and the high temperature zone was reduced when considering the transcritical effect. Within a certain range，as the radial annular seam width increased，the combustion efficiency initially decreased and then increased，as the axial annular seam width increased，the combustion efficiency decreased. A greater combustion efficiency can be achieved by reducing the axial annular seam width and increasing the radial annular seam width. When the total momentum ratio was less than 1， increasing axial momentum can effectively improve mixing. However， if the total momentum ratio was greater than 1， increasing axial momentum can hinder the improvement of mixing. The combustion efficiency decreased with the increase of the total momentum ratio. When the total momentum ratio for different operating conditions was similar， the operating condition with a higher momentum ratio exhibited a higher combustion efficiency. © 2024 Beijing University of Aeronautics and Astronautics (BUAA). All rights reserved.