Engineering Commons^™

The Influence Of Mixing Duct Length And Phase Of Flight On Wall Temperatures Of A Rocket Based Combined Cycle Engine In Ejector And Air-Augmented Modes, Jonathan Grow

Doctoral Dissertations and Master's Theses

Rocket Based Combined Cycle (RBCC) engines have been theorized as a possible means of powering launch vehicles and high-speed atmospheric vehicles. By incorporating aspects of both air-breathing and rocket propulsion, RBCC engines promise up to a 230 % increase in specific impulse over traditional chemical rocket propulsion by entraining a secondary flow of atmospheric air and mixing it with the exhaust of a rocket motor. Students within the Embry-Riddle Future Space Explorers and Developers Society (ERFSEDS) identified a
problem of excessive heating and structural failure of the mixing duct during launch and transonic flight of a student-built flight test vehicle. …

Rocket Motor Nozzle, Corey Hillegass

Williams Honors College, Honors Research Projects

For this honors research and senior design project, the authors will research, analyze, and manufacture a rocket motor nozzle for the Akronauts rocket design team. This research and design project will improve how the rocket design team will decide and manufacture nozzles going forward. The impact of this improvement allows the rocket design team to take steps toward being self-sustaining by manufacturing student designed parts as opposed to commercially bought parts. This will not only be successful in increasing student impact on future designs, but also provides a technical challenge for the authors and will present as an impressive feat …

Reconstruction Of Attenuated Hybrid Rocket Motor Chamber Pressure Signals Using Maximum Likelihood Estimation And Optimal Deconvolution, Evan M. Zelesnik

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Chamber pressure, as it develops during rocket combustion, strongly correlates with many of the internal motor ballistics, including combustion stability, fuel regression rate, and mass flow. Chamber pressure is also an essential measurement for calculating achieved thrust coefficient and characteristic velocity. Due to the combustion environment hostility, sensing chamber pressure with high-fidelity presents a difficult measurement problem, especially for solid and hybrid rocket systems where combustion by-products contain high amounts of carbon and other sooty materials. These contaminants tend to deposit within the pneumatic tubing used to transmit pressure oscillations from the thrust chamber to the sensing transducer. Partially clogged …

Design And Development Of Hybrid Rocket For Spaceport America Cup, Benjamin Barnhill, Sean Darling, Austin Springer, Adam Todd, Stewart Whaley

Chancellor’s Honors Program Projects

No abstract provided.

Senior Design - Hybrid Rocket Conceptual Design, Hardeo Chin

Hardeo Chin

Analysis Of Flammability Limits And Gas Properties Of A Solid Rocket Motor Test In A High Altitude Test Facility, Richard Scott Kirkpatrick

Masters Theses

The testing of solid and liquid rocket propulsion systems in a confined test facility often produces explosive or flammable gases which must be safely handled. Often inert gases such as nitrogen are used to lower the molar fraction of oxygen to low enough levels to minimize the probability of an explosion or deflagration. For this thesis, the chemical composition of these rocket exhaust gases mixed with air were used to determine the flammability limits of the gas mixture. Using the ideal gas law and the conservation of mass, the exhaust gas composition and gas properties such as pressure, temperature, volume …

Design Of The Structural And Propulsion Systems For The 2015 University Of Akron Rocket Team, Kyle W. Dehoff, Nicholas J. Hrusch

Williams Honors College, Honors Research Projects

No abstract provided.

Design And Analysis Of Reusable Nozzles For Cal Poly’S Hybrid Rocket Lab, Cheyne Austin, Jose Vargas

Aerospace Engineering

Two nozzles were designed and constructed for testing in the Cal Poly propulsion laboratory to explore which nozzle was the most capable in producing the most thrust. A 15 degree and 30 degree converging-diverging nozzles were machined and tested. Theory suggest that a bell nozzle would be the most efficient since all of the gasses generated in the combustion chamber are directed and accelerated by the throat leave the nozzle traveling along the thrust axis. All of the momentum of the gasses are directed axially thus resulting in maximum thrust. Thrust should also be produced by the converging-diverging nozzle and …

Catalytic Decomposition Of Nitrous Oxide Monopropellant For Hybrid Motor Ignition, Matthew D. Wilson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nitrous oxide (N₂O), a commonly-used industrial gas, is also often used as a rocket motor oxidizer. It has been used in both hybrid rocket motors (using a solid fuel and a liquid oxidizer) and liquid rocket engines (using liquid fuel and oxidizer).

As a liquid form, nitrous oxide is highly stable, but in vapor form it can be decomposed, releasing large amounts of heat as it dissociates into nitrogen and oxygen. This project investigates using the energy from decomposing nitrous oxide to ignite a hybrid or liquid rocket. Such a system would be practical in rocket …

Smore Revision: Ignition And User Interface, Arash Mehrparvar

Aerospace Engineering

The Static Methanol Oxygen Rocket Engine (SMORE) has undergone several revisions since its inception. This latest revision aimed to increase startup reliability and user safety in the operation of the rocket. The implementation of maintenance procedures, safeguards in the ignition system, as well as construction of a new control box and redesign of the igniter itself have accomplished these goals while keeping costs down and without modifying the current rocket setup. Startup reliability has increased drastically, so long as all other rocket setup procedures are followed properly. 250 subsequent firings of the rocket have proven an igniter reliability of more …

Optimization And Design For Heavy Lift Launch Vehicles, Paul Andreas Ritter

Masters Theses

The simulation and evaluation of an orbital launch vehicle requires consideration of numerous factors. These factors include, but are not limited to the propulsion system, aerodynamic effects, rotation of the earth, oblateness, and gravity. A trajectory simulation that considers these different factors is generated by a code developed for this thesis titled Trajectories for Heavy-lift Evaluation and Optimization (THEO). THEO is a validated trajectory simulation code with the ability to model numerous launch configurations. THEO also has the capability to provide the means for an optimization objective. Optimization of a launch vehicle can be specified in terms of many different …

Effect Of Unsteady Combustion On The Stability Of Rocket Engines, Tina Morina Rice

Doctoral Dissertations

Combustion instability is a problem that has plagued the development of rocket-propelled devices since their conception. It is characterized by the occurrence of high-frequency nonlinear gas oscillations inside the combustion chamber. This phenomenon degrades system performance and can result in damage to both structure and instrumentation.

The goal of this dissertation is to clarify the role of unsteady combustion in the combustor instability problem by providing the first quantified estimates of its effect upon the stability of liquid rocket engines. The combination of this research with a new system energy balance method, accounting for all dynamic interactions within a system, …

A Study Of Nonlinear Combustion Instability, Eric J. Jacob

Doctoral Dissertations

Combustion instability (CI) has been persistent in all forms of propulsion since their inception. CI is characterized by pressure oscillations within the propulsion system. If even a small fraction of the dense energy within the system is converted to acoustic oscillations the system vibrations can be devastating. The coupling of combustion and fluid dynamic phenomena in a nonlinear system poses CI as a significant engineering challenge.

Drawing from previous analysis, second order acoustic energy models are taken to third order. Second order analysis predicts exponential growth. The addition of the third order terms capture the nonlinear acoustic phenomena (such as …

Development Of A High Performance Micropropulsion System For Cubesats, Christopher Lorian Biddy

Master's Theses

Picosatellites are defined as satellites with a mass between 0.1 and 1kg (Miniaturized satellite). Picosatellites are typically designed to work together or function in formations (Miniaturized satellite). A specific type of Picosatellite known as CubeSats were introduced in 1999 and since then have increased in popularity so that there are now over 80 CubeSat programs around the world. CubeSats are defined as cubic units 10cm on each side and no more than 1kg in mass. CubeSats are required to conform to the CubeSat Standard created by California Polytechnic State University and Stanford University and be compatible with Cal Poly’s P-POD …