Effect of Convergent Section Contour on the Sonic Line in Rocket Engine Nozzles

ABSTRACT This study made a numeric evaluation of the effect of convergent geometry on the position and profile of the sonic line in rocket engine nozzles. To validate the numerical solution, two conical nozzles, from which experimental results are available in the literature, were used as reference. The tested convergent geometries have the same values for throat radius (Rt), radius of curvature at the throat of the divergent section (Rc3), divergent length, and ratio of areas. The numerical solutions have shown that convergent geometry changes the shape of the sonic line, and nozzles with lower radius ratios (Rc2/Rt) are more sensitive to the shape of the convergent section.