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Full-Text Articles in Propulsion and Power
Numerical Investigation Of Injector Location And Equivalence Ratio In A Flame‐Holder Cavity Scramjet, Matthew Sorenson
Numerical Investigation Of Injector Location And Equivalence Ratio In A Flame‐Holder Cavity Scramjet, Matthew Sorenson
Electronic Theses and Dissertations
This thesis presents a CFD-based parametric study of injector location and fuel rate in an ethylene-fueled flame-holder cavity scramjet using STAR-CCM+. Simulations are performed for three injector locations (x/D = 18, 36, and 54) and nine equivalence ratios spanning from ϕ = 0.2 to 1.0 in 0.1 increments. The study aims to determine how injector placement and fueling level alter scramjet performance across a broad operating sweep. The results show a clear regime change between ϕ = 0.2 and ϕ ≥ 0.3. At ϕ = 0.2, combustor behavior is weakly sensitive to injector location compared to the higher-fueling cases. For …
Optimizing Hypersonic Scramjets: A Numerical Study Of Fuel Type And Cavity Flameholder Design Impacts On Supersonic Combustion, Delaney Baumberger
Optimizing Hypersonic Scramjets: A Numerical Study Of Fuel Type And Cavity Flameholder Design Impacts On Supersonic Combustion, Delaney Baumberger
Electronic Theses and Dissertations
This thesis presents recommendations for optimizing hypersonic scramjets via a numerical study focusing on fuel type and cavity flameholder design and the impacts they have on supersonic combustion. The research is divided into two main investigations aimed at improving scramjet engine efficiency using two distinct geometrical configurations, a square cavity engine and an axisymmetric cavity engine. Each configuration is examined under Mach 2 inflow conditions to assess the role of geometric variation and fuel selection on combustion stability, flameholding, and overall performance. The first study focuses on a comparative assessment of hydrogen and ethylene as scramjet fuels to evaluate their …
Simulation Of Reacting Supersonic Flow In A Cavity Flameholder, Mohamed Benjelloun Touimi
Simulation Of Reacting Supersonic Flow In A Cavity Flameholder, Mohamed Benjelloun Touimi
Electronic Theses and Dissertations
Scramjet engines, or Supersonic Combustion Ramjets, are pivotal for achieving and maintaining hypersonic flight speeds. These engines leverage the high-speed airflow to compress and mix air and fuel for combustion. A significant challenge in Scramjet engine design is ensuring stable and efficient combustion within this high-speed environment. Cavity flameholders are crucial components that stabilize the combustion process by creating a subsonic region where the fuel-air mixture can ignite and sustain combustion. This research simulates this supersonic flow within the combustion chamber to accurately model and analyze the combustion dynamics. Various turbulence models, including RANS, and DES, are evaluated for their …
On The Simulation Of Supersonic Flame Holder Cavities With Openfoam, Zachary Chapman
On The Simulation Of Supersonic Flame Holder Cavities With Openfoam, Zachary Chapman
Electronic Theses and Dissertations
One of the next major advancements in the aerospace industry will be hypersonic flight. However, to achieve hypersonic flight, propulsion systems capable of reaching hypersonic speeds need to be developed. One of the more promising hypersonic propulsion systems is the scramjet engine, however, several problems still need to be explored before reliable scramjet engines can be produced, the biggest being keeping the engine ignited. This has led to the use of flame holder cavities to create a region of subsonic flow within the engine to allow combustion to occur. High experimental costs make the use of computational fluid dynamic (CFD) …
A Non-Reacting Passive Scalar Comparison Of Starccm And Openfoam In A Supersonic Cavity Flame Holder, Thomas Nuese
A Non-Reacting Passive Scalar Comparison Of Starccm And Openfoam In A Supersonic Cavity Flame Holder, Thomas Nuese
Electronic Theses and Dissertations
The scramjet engine equipped with a modern-day airliner would allow for very quick travel across the United States. The major problem is that designing such an engine and testing it to make sure it is safe would cost millions if not billions of dollars. Computational fluid dynamics allows for complex designs to be tested but can still take many days, weeks, or even months to complete. With the use of computational fluid dynamics (CFD), the scramjet engine can be analyzed to determine a quicker way to test and develop a reliable configuration in addition to analyzing the effects of different …
Simulation Of Non-Premixed Ethylene-Air Crossflow Jet Flame, Jennifer Onyinye Chikelu
Simulation Of Non-Premixed Ethylene-Air Crossflow Jet Flame, Jennifer Onyinye Chikelu
Electronic Theses and Dissertations
Computational fluid dynamics tool has been employed in the past to determine and analyze efficiency or performance in combustion engines and for combustion analysis. This paper represents a systematic investigation on the best model predicts the temperature and soot production in coflow jet flame, by applying various RANS turbulent model, soot models and radiation models in presence or absence of gravity. It also applies this model predicted in crossflow jet flame and investigates the velocity ratio (ratio of the velocity of fuel jet to the velocity of air stream) variation effect on temperature and soot production. ANSYS-Fluent CFD software tool …
Design And Evaluation Of A Propulsion System For Small, Compact, Low-Speed Maneuvering Underwater Vehicles, Florence M. Mbithi
Design And Evaluation Of A Propulsion System For Small, Compact, Low-Speed Maneuvering Underwater Vehicles, Florence M. Mbithi
Electronic Theses and Dissertations
Underwater vehicles used to perform precision inspection and non-destructive evaluation in tightly constrained or delicate underwater environments must be small, have low-speed maneuverability and a smooth streamlined outer shape with no appendages. In this thesis, the design and analysis of a new propulsion system for such underwater vehicles is presented. It consists primarily of a syringe and a plunger driven by a linear actuator and uses different inflow and outflow nozzles to provide continuous propulsive force. A prototype of the proposed propulsion mechanism is built and tested. The practical utility and potential efficacy of the system is demonstrated and assessed …