Rocket Nozzle Optimization



Project Report
In this project, I optimized the converging and diverging angles of a rocket nozzle with inlet specifications based on the AstroJays solid rocket motor requirements. The results found the optimal convergence and divergence angles to be 35° and 12° respectively. This agrees with existing literature which typically agree that ideal convergence and divergence angles should be 30-45° and 12-15° respectively. 

The optimization was performed by using CFD to calculate the exit conditions of nozzles of varying geometries in Ansys Fluent. The inlet diameter, inlet connection length, exit diameter, and throat diameter were held constant in all cases. The length of the inlet cone and outlet cone were determined by the converging and diverging angles. To find the optimal converging angle, the diverging angle was held constant while the converging angle varied. To find the optimal diverging angle, the converging angle was held constant while the diverging angle varied.

This project helped me develop my skills in CFD particularly with Ansys Fluent. I learned how to develop CFD simulations and how to mesh the model properly. Some changes I would make if I were to do the project again are to increase the curvature at the throat of the nozzle, to better optimize the meshing in areas of greater concern. In the project, the throat curvature was was effectively a sharp edge which does not reflect real conditions. Additionally, the mesh may be better optimized by condensing the mesh near key areas such as the throat and diverging section of the nozzle while the mesh can be less dense at the inlet. A future direction this project can take is to examine the transient response of the nozzle, as this simulation assumes static conditions.



Example Nozzle Geometry
Nozzle Mesh
Example Simulation Results

Contact

aren40@gatech.edu
408-464-5891
Alex Ren | LinkedIn