Florida Tech Rocketry
Florida Tech Rocketry
Liquid Rocket Engine Design
Liquid Rocket Engine Design
In October 2018 six other Florida Tech students and I formed the Florida Tech Rocketry team to compete in the Base 11 Space Challenge. The goal of this challenge was to design and build a single stage liquid fueled rocket, and launch that rocket to an altitude of 100 kilometers. From November 2018 to April 2020, I served as the team's Chief Propulsion Engineer. In that time I led the propulsion team as we developed an initial design for a liquid bi-propellant rocket engine. As the head of the propulsion team, I was involved in all elements of the design, including thrust chamber, injector, thermal protection, overall assembly, and the interfaces with the test stand.
In October 2018 six other Florida Tech students and I formed the Florida Tech Rocketry team to compete in the Base 11 Space Challenge. The goal of this challenge was to design and build a single stage liquid fueled rocket, and launch that rocket to an altitude of 100 kilometers. From November 2018 to April 2020, I served as the team's Chief Propulsion Engineer. In that time I led the propulsion team as we developed an initial design for a liquid bi-propellant rocket engine. As the head of the propulsion team, I was involved in all elements of the design, including thrust chamber, injector, thermal protection, overall assembly, and the interfaces with the test stand.
Together with other members of the team's leadership, we chose to design two variants of the engine: a ground test engine and a flight engine. The ground test engine would never fly, but would be used to test the design parameters and provided much needed data to inform the design of the flight engine. The ground test engine was designed with a large factor of safety due to significant unknowns in the design.
Together with other members of the team's leadership, we chose to design two variants of the engine: a ground test engine and a flight engine. The ground test engine would never fly, but would be used to test the design parameters and provided much needed data to inform the design of the flight engine. The ground test engine was designed with a large factor of safety due to significant unknowns in the design.
The final design for the ground variant was a pressure fed, ablatively cooled engine using kerosene and liquid oxygen as propellants. The injector was orifice pintle design. The engine had a predicted sea level thrust of 11.2 kN and a predicted sea level specific impulse of 230 seconds.
The final design for the ground variant was a pressure fed, ablatively cooled engine using kerosene and liquid oxygen as propellants. The injector was orifice pintle design. The engine had a predicted sea level thrust of 11.2 kN and a predicted sea level specific impulse of 230 seconds.
The ground test variant used a carbon steel tube as the pressure vessel. The internal and external diameters were to be left near their stock dimensions in order to maximize the factor of safety. The ablative composite was designed such that the internal profile would form the combustion chamber and converging-diverging nozzle, and the external profile would form a cylinder matching the internal diameter of the steel tube.
The ground test variant used a carbon steel tube as the pressure vessel. The internal and external diameters were to be left near their stock dimensions in order to maximize the factor of safety. The ablative composite was designed such that the internal profile would form the combustion chamber and converging-diverging nozzle, and the external profile would form a cylinder matching the internal diameter of the steel tube.
For more information on the design rational, the various analyses performed, and details of the design, the final report on the ground variant can be found here.
For more information on the design rational, the various analyses performed, and details of the design, the final report on the ground variant can be found here.
While the ground test engine had neither been manufactured nor tested by the time I graduated, I developed a detailed manufacturing plan prior to graduation, and began early plans for the design of flight engine. This preliminary design consisted of a minimum-thickness ablative liner with a carbon-fiber overwrap forming the pressure vessel. The firings of the ground test engine would be used to determine the maximum pressure experienced the combustion chamber and to refine our model of the ablative composite. The refined model would determine the required profiles of the ablative liner, and the recorded pressures would set the thickness of the overwrap. The design of the injector would remain largely unchanged, but would be refined to reduce weight as much as practical.
While the ground test engine had neither been manufactured nor tested by the time I graduated, I developed a detailed manufacturing plan prior to graduation, and began early plans for the design of flight engine. This preliminary design consisted of a minimum-thickness ablative liner with a carbon-fiber overwrap forming the pressure vessel. The firings of the ground test engine would be used to determine the maximum pressure experienced the combustion chamber and to refine our model of the ablative composite. The refined model would determine the required profiles of the ablative liner, and the recorded pressures would set the thickness of the overwrap. The design of the injector would remain largely unchanged, but would be refined to reduce weight as much as practical.