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Proceedings of the 27th National and 5th International ISHMT-ASTFE Heat and Mass Transfer Conference December 14-17, 2023, IIT Patna, Patna-801106, Bihar, India
December, 14-17, 2023, Bihar, India

Effect of change in port shape on the performance of a hybrid rocket motor

Get access (open in a dialog) DOI: 10.1615/IHMTC-2023.980
pages 605-611


A hybrid rocket motor (HRM) is a form of chemical rocket propulsion that utilizes propellants stored in distinct physical states. A novel port design of various grain configuration were investigated with the interest to improve the mixing and combustion of the fuel and oxidizer, removing the need for specialized injectors or energetic additives, to meet the intrinsic difficulty of low regression rates in HRMs. In this study, solid grains of polyvinyl chloride (PVC) and di-butyl phthalate (DBP) were used as the experimental fuels, and pressurized gaseous oxygen was used as the oxidizer. In the present work, the performance of a hybrid rocket motor using different grain configurations was examined. The use of different port grains with edges could create recirculation zones with the increasing complexity of the motor. The main focus was investigating the effects of three, four, and five edges. So, keeping the orientation in mind the triangular, square, and pentagonal ports were chosen. The regression rates of experimented grains were 50 to 60 percent higher at Gox of 7.5 g/cm2-sec in comparison to normal port grain. The combustion efficiency of edged port grains enhanced from 3% to 61% in comparison with conventional port grain. The pressure build-up inside the combustion chamber and thrust generation due to optimal expansion through a conventional de-Laval nozzle were also increased for the edged port grains concerning the conventional port grain.