Regression-Rate Evaluation of Hybrid-Rocket Fuel Grain with a Star-Fractal Swirl Port

A three-dimensional-printed solid fuel grain with a star-fractal swirl port was developed to improve the regression rate of hybrid rockets. The printing material used for grains an acrylonitrile-butadiene-styrene resin. Nitrous oxide employed as oxidizer. Combustion experiments on rocket engine showed that appeared thrust and specific impulse compared classical circular ports when tested using same oxidizer mass flow is controllable parameter engines. After experiments, burned were cut web thicknesses measured evaluate local rate. It found surface regressed more rapidly near concave parts star fractal rather than convex parts. Next, rates axially averaged. axially-averaged much higher those ports. Finally, numerical approach level set method evaluating time- space-averaged developed. This validated by comparing rates.