Author: Sean Francis Connolly-Boutin
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
A rotating detonation engine (RDE) is a new, more thermodynamically efficient, propulsion concept that replaces the traditional constant pressure combustion mechanism found in all currently used rockets and power generation devices. The constant pressure combustion is replaced by a detonation wave: a coupled shock-flame complex propagating at speeds of up to 2-3 km/s and generating combustion products at pressures 5-10 times the initial reactant pressure. This pressure gain through the combustion process leads to more compact, simpler devices that no longer require (or depend less upon) initial reactant precompression. Detonation-based cycles also have the added advantage of being theoretically more thermodynamically efficient than their constant pressure combustion counterparts. As such, RDEs have become increasingly popular in the propulsion research community, although there is still a lack of understanding in the underlying physics which govern their operability, though the existence of a minimum mass flow rate limit for stable operation has been observed. To help engineers and researchers design an RDE, a model was developed which combines geometric properties, 1D isentropic flow, and detonation physics to predict the stable operating bounds of an RDE. An engine testing facility was also constructed in collaboration with McGill University to test RDEs and confirm the performance of the prediction model developed.
Author: Jiun-Ming Li
Publisher: Springer
ISBN: 3319689061
Category : Technology & Engineering
Languages : en
Pages : 246
Get Book Here
Book Description
This book focuses on the latest developments in detonation engines for aerospace propulsion, with a focus on the rotating detonation engine (RDE). State-of-the-art research contributions are collected from international leading researchers devoted to the pursuit of controllable detonations for practical detonation propulsion. A system-level design of novel detonation engines, performance analysis, and advanced experimental and numerical methods are covered. In addition, the world’s first successful sled demonstration of a rocket rotating detonation engine system and innovations in the development of a kilohertz pulse detonation engine (PDE) system are reported. Readers will obtain, in a straightforward manner, an understanding of the RDE & PDE design, operation and testing approaches, and further specific integration schemes for diverse applications such as rockets for space propulsion and turbojet/ramjet engines for air-breathing propulsion. Detonation Control for Propulsion: Pulse Detonation and Rotating Detonation Engines provides, with its comprehensive coverage from fundamental detonation science to practical research engineering techniques, a wealth of information for scientists in the field of combustion and propulsion. The volume can also serve as a reference text for faculty and graduate students and interested in shock waves, combustion and propulsion.
Author: Andrew Ryan Mizener
Publisher:
ISBN:
Category : Acoustic phenomena in nature
Languages : en
Pages : 226
Get Book Here
Book Description
The rotating detonation engine (RDE) is a promising propulsion concept that has the potential to offer increased thermodynamic performance in a compact package with no moving parts. A series of analytical and experimental investigations was carried out on RDEs with the joint goal of investigating swirl, torque, and a range of other design parameters of interest. The model and experimental facility were then applied to related problems with the goal of advancing the understanding of RDE applications. A flexible, low-order, semi-empirical model for a rotating detonation engine was presented. The model was formulated to be able to run broad parametric analyses more efficiently than numerical modeling. The presence of swirl at the exit plane of RDEs is still debated, so the model was formulated to leave open this possibility. Parametric analysis was conducted to determine the effect of a range of engine design parameters on performance. Exit swirl and torque were shown to be small but not uniquely zero. The model was combined with a waverider forebody model. Together, these were used to conduct parametric analysis of the sensitivity of integrated performance to freestream, waverider forebody, and RDE design parameters. Practical limitations on the Mach number of detonation engines operating in supersonic flows were presented and discussed. Peak performance was seen at the point of maximum forebody pressure recovery. Thrust and torque were shown to be sensitive to body shape and freestream parameters, while specific impulse and thrust-specific fuel consumption were not. The design of a rotating detonation engine and experimental test facility were presented and discussed. The facility was designed and instrumented to allow the measurement of resultant torque on the engine as well as take thrust and pressure readings. A series of tests was conducted using the engine, with no steadily-propagating detonation waves detected. Pressure, torque, thrust, and frequency data were presented and discussed. A high-speed camera was used to visualize the exhaust plume and the flame structure inside the annulus, which similarly failed to detect a detonation wave. The camera was then used to conduct high-speed visualizations of the ignition process inside the engine for both spark plug and predetonator igniters. Both methods showed the creation of two counter-rotating detonation waves which intersected and canceled each other out on the far side of the annulus. Pressure waves were observed to continue to rotate for several periods before dying out. The qualitative observations from the visualizations were supported by the pressure data. Detailed visualizations were performed to quantitatively investigate the propagation of the initial combustion front around the annulus for varying degrees of injector swirl. Predetonator ignition was observed to directly initiate a detonation, whereas deflagration-to-detonation transition was observed for spark plug ignition. Injector swirl promoted transition in combustion waves propagating into the swirl and depressed it in waves propagating with the swirl. Overdriven detonations were observed for both ignition methods. A discussion of the possible causes for the failure to sustain a detonation wave was presented and discussed.
Author: Zonglin Jiang
Publisher: Springer Nature
ISBN: 9811970025
Category : Science
Languages : en
Pages : 281
Get Book Here
Book Description
This book highlights the theories and research progress in gaseous detonation research, and proposes a universal framework theory that overcomes the current research limitations. Gaseous detonation is an extremely fast type of combustion that propagates at supersonic speed in premixed combustible gas. Being self-sustaining and self-organizing with the unique nature of pressure gaining, gaseous detonation and its gas dynamics has been an interdisciplinary frontier for decades. The research of detonation enjoyed its early success from the development of the CJ theory and ZND modeling, but phenomenon is far from being understood quantitatively, and the development of theories to predict the three-dimensional cellular structure remains a formidable task, being essentially a problem in high-speed compressible reacting flow. This theory proposed by the authors’ research group breaks down the limitation of the one-dimensional steady flow hypothesis of the early theories, successfully correlating the propagation and initiation processes of gaseous detonation, and realizing the unified expression of the three-dimensional structure of cell detonation. The book and the proposed open framework is of high value for researchers in conventional applications such as coal mine explosions and chemical plant accidents, and state-of-the-art research fields such as supernova explosion, new aerospace propulsion engines, and detonation-driven hypersonic testing facilities. It is also a driving force for future research of detonation.
Author: Eric M. Braun
Publisher:
ISBN:
Category : Combustion engineering
Languages : en
Pages :
Get Book Here
Book Description
A series of related analytical and experimental studies are focused on utilizing detonations for emerging propulsion and power generation devices. An understanding of the physical and thermodynamic processes for this unsteady thermodynamic cycle has taken over 100 years to develop. An overview of the thermodynamic processes and development history is provided. Thermodynamic cycle analysis of detonation-based systems has often been studied using surrogate models. A real gas model is used for a thermal e ciency prediction of a detonation wave based on the work and heat speci ed by process path diagrams and a control volume analysis. A combined rst and second law analysis aids in understanding performance trends for di erent initial conditions. A cycle analysis model for an airbreathing, rotating detonation wave engine (RDE) is presented. The engine consists of a steady inlet system with an isolator which delivers air into an annular combustor. A detonation wave continuously rotates around the combustor with side relief as the ow expands towards the nozzle. Air and fuel enter the combustor when the rarefaction wave pressure behind the detonation front drops to the inlet supply pressure. To create a stable RDE, the inlet pressure is matched in a convergence process with the average combustor pressure by increasing the annulus channel width with respect to the isolator channel. Performance of this engine is considered using several parametric studies. RDEs require a fuel injection system that can cycle beyond the limits of mechanical valves. Fuel injectors composed of an ori ce connected to a small plenum cavity were mounted on a detonation tube. These fuel injectors, termed uidic valves, utilize their geometry and a supply pressure to deliver fuel and contain no moving parts. Their behavior is characterized in order to determine their feasibility for integration with high-frequency RDEs. Parametric studies have been conducted with the type of fuel injected, the ori ce diameter, and the plenum cavity pressure. Results indicate that the detonation wave pressure temporarily interrupts the uidic valve supply, but the wave products can be quickly expelled by the fresh fuel supply to allow for refueling. The interruption time of the valve scales with injection and detonation wave pressure ratios as well as a characteristic time. The feasibility of using a detonation wave as a source for producing power in conjunction with a linear generator is considered. Such a facility can be constructed by placing a piston{spring system at the end of a pulsed detonation engine (PDE). Once the detonation wave re ects o the piston, oscillations of the system drive the linear generator. An experimental facility was developed to explore the interaction of a gaseous detonation wave with the piston. Experimental results were then used to develop a model for the interaction. Governing equations for two engine designs are developed and trends are established to indicate a feasible design space for future development.
Author: James Koch
Publisher:
ISBN:
Category : Detonation waves
Languages : en
Pages : 147
Get Book Here
Book Description
The Rotating Detonation Engine (RDE) is a novel rocket combustor configuration that features a periodic, high aspect ratio (length of flowpath versus transverse thickness) combustion chamber designed to promote tangential high-frequency combustion instabilities typical of conventional rockets. Most RDEs are comprised of concentric cylinders whereby the annular gap between the cylinders constitutes the flow domain. The annular gap acts as geometric confinement suitable for robustly promoting the self-steepening of pressure and density gradients caused by combustion. The RDE's steady operation is the saturation of this highly nonlinear self-steepening process: a number of circumferentially traveling detonation waves. The benefits of the RDE include a larger stable operating envelope and potentially higher thermodynamic cycle efficiency over conventional rockets. However, the collective behavior of the detonation waves present in the RDE combustion chamber, while readily observable, is not well understood nor sufficiently characterized, especially with respect to engineering metrics such as thrust or engine stability. This dissertation is a comprehensive experimental, theoretical, and numerical study that aims to link observed the gasdynamic engine behavior to the nonlinear dynamics of the detonation waves. The experimental test campaign features engines of two sizes: a 154-mm flowpath outer diameter (OD) engine and a 76mm OD engine. A sweep of boundary conditions (inlet and outlet pressures) was conducted using the 154-mm RDE at reduced mass flux conditions to establish the engine0́9s gasdynamic operating regimes, namely the attainment of a thermal choke at the exit of the annular duct. Similarly, using the 76-mm RDE at elevated mass flux conditions, the engine0́9s response to the attainment of an axial thermal choke is investigated with respect to changes in total injection area. From both sets of testing, found is that the choked annular duct acts as a boundary condition that fixes the upstream pressure required to steadily deliver a given mass flow rate of propellant of a specified chemical energy potential. By recording the space-time history of the detonation waves with a high speed camera, a diverse set of behavior was recorded and collected during the experimental test campaign. Such behavior includes wave nucleation, destruction, mode-locking of multiple waves, persistent wave modulation, and pulsating plane waves. By drawing upon the well-established fields of nonlinear waves and detonation analog modeling, a Rotating Detonation Engine analog system is proposed. This model system is an adaptation of the Majda detonation analog to a periodic domain with imposed dissipation and propellant regeneration. The dissipative process is constrained to enforce the same global behavior seen in experiments, namely the self-similar pressure operating profiles attained with a thermal choke point at the exit of the engine. Within the reduced-scope of co-rotating detonation waves, the RDE analog system is found to qualitatively reproduce all transients and modes of operation seen in experiments. The propagating waves are classified as autosolitons, or localized structures with offsetting dominant balance physics. Within this context, the dominant balance physics are identified and found to be strongly influenced by input-output energy dynamics and act across several orders of spatial and temporal scales. In this manner, the global multi-scale balance physics give rise to the traveling detonation waves and their associated dynamics - not exclusively the frontal dynamics prescribed by classical detonation theory. Furthermore, the underlying fundamental Hopf bifurcation to time-periodic modulation of the collection of waves is confirmed to exist in the RDE analog. Comparisons between computed Hopf orbits of the model and experimentally-extracted kinematic traces are made showing good qualitative agreement.
Author: Fouad Sabry
Publisher: One Billion Knowledgeable
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 349
Get Book Here
Book Description
What Is Pulse Detonation Engine A pulse detonation engine (PDE) is a type of propulsion system that uses detonation waves to combust the fuel and oxidizer mixture. The engine is pulsed because the mixture must be renewed in the combustion chamber between each detonation wave and the next. Theoretically, a PDE can operate from subsonic up to a hypersonic flight speed of roughly Mach 5. An ideal PDE design can have a thermodynamic efficiency higher than other designs like turbojets and turbofans because a detonation wave rapidly compresses the mixture and adds heat at constant volume. Consequently, moving parts like compressor spools are not necessarily required in the engine, which could significantly reduce overall weight and cost. PDEs have been considered for propulsion since 1940. Key issues for further development include fast and efficient mixing of the fuel and oxidizer, the prevention of autoignition, and integration with an inlet and nozzle. To date, no practical PDE has been put into production, but several testbed engines have been built and one was successfully integrated into a low-speed demonstration aircraft that flew in sustained PDE powered flight in 2008. In June 2008, the Defense Advanced Research Projects Agency (DARPA) unveiled Blackswift, which was intended to use this technology to reach speeds of up to Mach 6 How You Will Benefit (I) Insights, and validations about the following topics: Chapter 1: Pulse Detonation Engine Chapter 2: Nuclear Pulse Propulsion Chapter 3: Rotating Detonation Engine Chapter 4: AIMStar Chapter 5: Antimatter-catalyzed nuclear pulse propulsion Chapter 6: Antimatter rocket Chapter 7: Nuclear electric rocket Chapter 8: Nuclear power in space Chapter 9: Nuclear propulsion Chapter 10: Nuclear thermal rocket Chapter 11: Project Pluto Chapter 12: Fission-fragment rocket (II) Answering the public top questions about pulse detonation engine. (III) Real world examples for the usage of pulse detonation engine in many fields. (IV) 17 appendices to explain, briefly, 266 emerging technology in each industry to have 360-degree full understanding of pulse detonation engine' technologies. Who This Book Is For Professionals, undergraduate and graduate students, enthusiasts, hobbyists, and those who want to go beyond basic knowledge or information for any kind of pulse detonation engine.
Author: Craig A. Nordeen
Publisher:
ISBN:
Category :
Languages : en
Pages : 201
Get Book Here
Book Description
Author: Gullapalli Sivaramakrishna
Publisher: Springer Nature
ISBN: 9811923787
Category : Technology & Engineering
Languages : en
Pages : 633
Get Book Here
Book Description
This book presents the select proceedings of the 3rd National Aerospace Propulsion Conference (NAPC 2020). It discusses the recent trends in the area of aerospace propulsion technologies covering both air-breathing and non-air-breathing propulsion. The topics covered include state-of-the-art design, analysis and developmental testing of gas turbine engine modules and sub-systems like compressor, combustor, turbine and alternator; advances in spray injection and atomization; aspects of combustion pertinent to all types of propulsion systems and nuances of space, missile and alternative propulsion systems. The book will be a valuable reference for beginners, researchers and professionals interested in aerospace propulsion and allied fields.
Author: Richard Blümner
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
