Hydrocarbon-Fueled Scramjet Combustor Flowpath Development for Mach 6-8 HIFire Flight Experiments (Preprint).


Book Description

The Hypersonic International Flight Research Experimentation (HIFiRE) Program is a joint effort between the US Air Force Research Laboratory (AFRL) and the Australian Defence Scientific and Technology Organisation (DSTO) devoted to the study of basic hypersonic phenomena through flight experimentation. Experiments have been planned to explore the operating, performance, and stability characteristics of a simple hydrocarbon-fueled scramjet combustor as it transitions from dual-mode to scramjet-mode operation and during supersonic combustion at Mach 8+ flight conditions. This paper describes initial efforts to develop the isolator/combustor flowpath for these flight experiments. Computational results suggest that excellent performance can be obtained at Mach 8 flight conditions with simple inclined wall fuel injection upstream of a cavity-based flameholder using both ethylene and a mixture of ethylene and methane. Computational analyses have also been used to explore combustor operability and performance at flight Mach numbers between 6 and 8 to identify where mode transition can be expected to occur.







Integrated Analysis of Scramjet Flowpath and Innovative Inlets (Preprint).


Book Description

An overview is presented of fundamental and practical insights obtained on scramjet flowpaths during a three year Challenge Project utilizing high fidelity methodologies and advanced postprocessing techniques. Simulations are employed to analyze the principal phenomena, including inlet distortion, fuel-air mixing, ignition and thrust generation at freestream Mach numbers between 6 and 8. In addition to guiding the evolution and execution of high-speed ground and flight experiments, the discovery objective of the project identifies trends and suggests optimization strategies for rapid response and kinetic kill hypersonic vehicles. Three inlet designs are considered, including the traditional rectangular cross-section configuration and two streamline traced variants denoted Scoop and Jaws, each attached to a corresponding cavity-based flame-holding combustor. The simulations reveal the characteristic distortion signature of each design. Parametric analyses provide insight into major performance issues, including the effects of distortion on combustion, injector port configurations and gaseous versus liquid (multi-phase) injection of simple and complex fuels. Some results are consistent with intuition: for example, streamwise-staggered and spanwise-interlaced injectors enhance diffusive mixing. Other findings are not intuitive and point to competing constraints.




Scramjet Combustion


Book Description

Scramjet Combustion explores the development of a high-speed scramjet engine operating in the supersonic/hypersonic range for various air and space transport applications. The book explains the basic structure, components, working cycle, and the relevant governing equations in a clear manner that speaks to both advanced and more novice audiences. Particular attention is paid to efficient air–fuel combustion, looking at both the underlying fundamentals of combustion as well strategies for obtaining optimum combustion efficiency. Methods for reaching the chemically correct air–fuel ratio, subsequent flame, and combustion stabilization as air enters at supersonic speed are also outlined. Further, it includes the continuous on-going efforts, innovations, and advances with respect to the design modification of scramjet combustors, as well as different strategies of fuel injections for obtaining augmented performance while highlighting the current and future challenges. - Outlines the fundamentals of scramjet engines including their basic structure and components, working cycle, governing equations, and combustion fundamentals affecting the combustion and mixing processes - Presents new design modifications of scramjet combustors and different fuel injection strategies including combined fuel injection approaches - Discusses core topics such as chemical kinetics in supersonic flow, fuel–air mixing methods, strategies for combating combustion difficulties, and subsequent flame and combustion stabilization that can be applied to scramjets - Describes the pedagogy for computational approaches in simulating supersonic flows







The Scramjet Engine


Book Description

The renewed interest in high-speed propulsion has led to increased activity in the development of the supersonic combustion ramjet engine for hypersonic flight applications. In the hypersonic regime the scramjet engine's specific thrust exceeds that of other propulsion systems. This book, written by a leading researcher, describes the processes and characteristics of the scramjet engine in a unified manner, reviewing both the theoretical and experimental research. The focus is on the phenomena that dictate the thermo-aerodynamic processes encountered in the scramjet engine, including component analyses and flowpath considerations; fundamental theoretical topics related to internal flow with chemical reactions and non-equilibrium effects, high-temperature gas dynamics, and hypersonic effects are included. Cycle and component analyses are further described, followed by flowpath examination. Finally, the book reviews the current experimental and theoretical capabilities and describes ground testing facilities and computational fluid dynamics facilities developed to date for the study of time-accurate, high-temperature aerodynamics.




Methodical Aspects of Investigation of Kerosene Ignition and Combustion in Scramjet Model


Book Description

There have been studies on hydrocarbon-fueled vehicle concept in a range of Mach numbers. It is assumed that the upper bounds of using hydrocarbon fuels lie between Mach numbers 6-8. Many investigations of scramjets with a hydrogen fuel on models in wind tunnels of are known. But only few works are known, which concerned the study of hydrocarbon fuel combustion and especially combustion of liquid kerosene. Therefore, the investigation of liquid fuel combustion is very important. It is necessary to evaluate the possibility of full engine model tests in a hot-shot wind tunnel under flight conditions.




Hypersonic Airbreathing Propulsion


Book Description

An almost entirely self-contained engineering textbook primarily for use in undergraduate and graduate courses in airbreathing propulsion. It provides a broad and basic introduction to the elements needed to work in the field as it develops and grows. Homework problems are provided for almost every individual subject. An extensive array of PC-based user-friendly computer programs is provided in order to facilitate repetitious and/or complex calculations. Annotation copyright by Book News, Inc., Portland, OR




Hypersonic Vehicles


Book Description

In the aviation field there is great interest in high-speed vehicle design. Hypersonic vehicles represent the next frontier of passenger transportation to and from space. However, several design issues must be addressed, including vehicle aerodynamics and aerothermodynamics, aeroshape design optimization, aerodynamic heating, boundary layer transition, and so on. This book contains valuable contributions focusing on hypervelocity aircraft design. Topics covered include hypersonic aircraft aerodynamic and aerothermodynamic design, especially aeroshape design optimization, computational fluid dynamics, and scramjet propulsion. The book also discusses high-speed flow issues and the challenges to achieving the dream of affordable hypersonic travel. It is hoped that the information contained herein will allow for the development of safe and efficient hypersonic vehicles.




Advances in Flight Testing


Book Description