Download or read book Practical Implementation of Pulse Detonation Engines written by T. R. A. Bussing and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Detonation Control for Propulsion written by Jiun-Ming Li and published by Springer. This book was released on 2017-12-05 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Pulse Detonation Engine written by Fouad Sabry and published by One Billion Knowledgeable. This book was released on 2021-10-14 with total page 349 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Detonation Initiation Studies and Performance Results for Pulsed Detonation Engine Applications written by and published by . This book was released on 2001 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: An in-house computational and experimental program to investigate and develop an air breathing pulse detonation engine (PDE) that uses a practical fuel (kerosene based, fleet-wide use, JP type) is currently underway at the Combustion Sciences Branch of the Turbine Engine Division of the Air Force Research Laboratory (AFRL/PRTS). PDE's have the potential of high thrust, low weight, low cost, high scalability, and wide operating range, but several technological hurdles must be overcome before a practical engine can be designed. This research effort involves investigating such critical issues as: detonation initiation and propagation; valving, timing and control; instrumentation and diagnostics; purging, heat transfer, and repetition rate; noise and multi-tube effects; detonation and deflagration to detonation transition modeling; and performance prediction and analysis. An innovative, four-detonation-tube engine design is currently in test and evaluation. Preliminary data are obtained with premixed hydrogen/air as the fuel/oxidizer to demonstrate proof of concept and verify models. Techniques for initiating detonations in hydrogen/air mixtures are developed without the use of oxygen enriched air. An overview of the AFRL/PRTS PDE development research program and hydrogen/air results are presented.

Download or read book Combustion Processes in Propulsion written by Gabriel Roy and published by Butterworth-Heinemann. This book was released on 2006 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemical propulsion comprises the science and technology of using chemical reactions of any kind to create thrust and thereby propel a vehicle or object to a desired acceleration and speed. Cumbustion Processes in Propulsion focuses on recent advances in the design of very highly efficient, low-pollution-emitting propulsion systems, as well as advances in testing, diagnostics and analysis. It offers unique coverage of Pulse Detonation Engines, which add tremendous power to jet thrust by combining high pressure with ignition of the air/fuel mixture. Readers will learn about the advances in the reduction of jet noise and toxic fuel emissions-something that is being heavily regulated by relevant government agencies. Lead editor is one of the world's foremost combustion researchers, with contributions from some of the world's leading researchers in combustion engineering Covers all major areas of chemical propulsion-from combustion measurement, analysis and simulation, to advanced control of combustion processes, to noise and emission control Includes important information on advanced technologies for reducing jet engine noise and hazardous fuel combustion emissions

Download or read book Gasdynamic Phenomena and Propulsive Performance of Pulse Detonation Engines written by James T. Peace and published by . This book was released on 2019 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: The pulsed detonation engine (PDE) is an advanced propulsion system that makes use of intermittent detonations to provide thrust. In recent decades, the PDE has been at the center of various propulsion research efforts focused on practical implementation of a reliable detonation-based engine for aerospace propulsion applications. However, many design challenges remain to be solved due to the PDEs unsteady operating characteristics. In particular, the unsteady nature of the thrust chamber flow field inherent to the PDE operation makes the design of nozzles aimed at adequately expanding the burned detonation products especially difficult. In order to address this design challenge, a series of related analytical, numerical, and experimental studies have been conducted, which are focused on investigating the manner in which the PDE propulsive performance is governed by the various gasdynamic processes occurring within the thrust chamber and nozzle flow fields. In this study, three primary PDE configurations are considered. These configurations include fully- and partially-filled PDEs, and PDEs equipped with diverging nozzles. For each configuration, a comprehensive description of the PDE flow field is provided, whereby details concerning the evolution and interaction of various gasdynamic waves and discontinuities are discussed. Additionally, the dominant gasdynamic processes within the thrust chamber and nozzle flow fields are identified, as these processes must be appropriately modeled in order to accurately evaluate the propulsive performance.The collision of a detonation wave with a contact surface separating detonable and non-combustible mixtures is a fundamental gasdynamic interaction process that takes place every cycle in the cyclic operation of the PDE. This interaction can drastically influence the evolving thrust chamber flow field and the subsequent propulsive performance metrics. To improve its understanding, this gasdynamic interaction is investigated analytically in order to predict the resulting transmitted shock wave properties, and the necessary conditions for a shock, Mach, or rarefaction wave to reflect at the contact surface. Concurrently, this interaction is investigated experimentally with the use of a detonation-driven shock tube. The analytical and experimental results indicate that the transmitted shock can either be amplied or attenuated depending on the reflection type at the contact surface, and the ratio of the acoustic impedance across the interface. A quasi-one-dimensional method of characteristics (MOC) model is developed to evaluate the single-cycle gasdynamic flow field and associated propulsive performance of general PDE configurations. The model incorporates the current detonation-contact surface interaction results in order to accurately treat the one-dimensional collision of a detonation wave with a contact discontinuity. Additionally, the MOC model is developed using a simplified unit process approach with an explicit inverse time marching algorithm in order to readily construct the complex thrust chamber flow field along a predefined grid. A thorough validation of the model is presented over a broad range of operating conditions with existing higher-fidelity numerical and experimental performance data for fully- and partially-filled PDEs, and PDEs equipped with diverging nozzles. This includes PDEs operating with a variety of detonable fuels, non-combustible inert mixtures, ll fractions, blowdown pressure ratios, and nozzle expansion area ratios. Lastly, a detailed discussion of the model limitations is provided, and particular operating conditions that lead to a breakdown of the assumptions used in the development of the model are addressed. A simplified analytical model is developed based on control volume analysis for evaluating the primary performance metrics of a general fully-filled PDE. The MOC model is used to justify and establish a simplified thrust relation based solely on the ow properties at the exit plane of a fully-filled PDE. A detailed analytical description of the thrust chamber flow field is provided, from which an analytical piece wise expression for thrust is derived based on the exit plane pressure history. This expression is then used to evaluate the specific impulse, total impulse, and time-averaged thrust of a fully-filled PDE. This simplified model is validated against the current MOC model and higher-fidelity numerical and experimental performance data for a variety of detonable fuels, equivalence ratios, and blowdown pressure ratios.Using the current MOC model, the single-cycle propulsive performance of partially-filled PDEs is investigated. The results of the detonation-contact surface interaction study are used to tailor the acoustic impedance of the non-combustible mixture at a fixed fill fraction in order to demonstrate the sensitivity of the thrust chamber flow field to the non-combustible acoustic impedance. Subsequently, the detonable fill fraction and noncombustible acoustic impedance are varied simultaneously in order to characterize the general partially-lled PDE performance. The partial-filling performance benefit is also investigated by varying the initial pressure and temperature of the non-combustible mixture in order to highlight the advantage of using a cold purge gas during operation, and disadvantage of operating in sub-atmospheric environments. It is demonstrated that the partially-filled specific impulse performance results generated with the MOC model from these various parametric investigations are successfully modeled using a previously developed scaling law, whereby this scaling law is extended in the current work to partially-filled total impulse and time-averaged thrust.Similarly, the single-cycle propulsive performance of PDEs with diverging nozzles is examined. A parametric investigation is conducted to characterize the combined effects of nozzle expansion area and blowdown pressure ratios on the resulting thrust chamber and nozzle flow fields. Detailed discussion of the transient nozzle flow field is provided in order to emphasize the influence of non-combustible acoustic impedance on the partial-fill effect in diverging nozzles. Moreover, a comparative study is used to demonstrate the performance advantages of a diverging nozzle in sub-atmospheric environments compared to a straight extension nozzle. Lastly, a detailed parametric investigation is conducted by simultaneously varying the nozzle length, expansion area ratio, and blowdown pressure ratio in order to determine the optimum nozzle performance characteristics. An analytical model is formulated to predict the strength and motion of a transmitted shock wave through a general contour diverging nozzle for PDEs. The model is derived on the basis of a two-equation approximation of the generalized CCW (Chester Chisnell Whitham) theory for treating general shock dynamics in non-uniform channels. A major feature of the two-equation model is the ability to incorporate non-uniformity in the flow immediately following the shock wave, which turns out to be essential for describing the transmitted shock dynamics in PDE nozzles. This model is then used to demonstrate the effects of thrust chamber length on the magnitude of ow non-uniformity behind the transmitted shock entering the nozzle, and how drastically this can influence the nature of shock attenuation within the nozzle. Further, the shock dynamics model is used in conjunction with the MOC model to demonstrate how different nozzle wall curvature influences the PDE propulsive performance, due to the changes in transmitted shock attenuation and gasdynamic over-expansion in the nozzle flow field during the nozzle starting process.

Download or read book Plasma Ignition Systems for Use in Pulsed Detonation Engines written by Jennifer Reilly Corrigan and published by . This book was released on 2006 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The Pulse Detonation Engine (PDE) is an extremely exciting type of pulsejet. With recent advances in technology, coupled with operational prospects, there has been a renewed interest in PDEs. Despite the advantages of the PDE, there are many improvements still to be made. One way of improving a PDE is to decrease ignition and deflagration to detonation transition (DDT) times. It is hypothesized that this can be accomplished with the use of plasma ignition systems because of the high energy capabilities of the system. While the high voltage requirements of a plasma ignition system would add complications to practical use of PDEs in aircraft, if the plasma ignition system can decrease the ignition delay and DDT times by a large amount, it would be most beneficial to use it. Lowering the ignition delay and DDT times would allow the PDE to operate at higher frequencies, decreasing lower frequency vibrations and increasing the thrust generated and overall efficiency. In this study, three plasma ignition systems were tested in various positions throughout the PDE cylinder head. The results of the experimental testing showed that the plasma ignition systems were able to reduce the ignition delay by a factor of two, but the DDT times for the plasma ignition systems showed a large variance. There were also complications with the plasma ignition systems due to the harsh environment of the PDE.

Download or read book Development of a Gas Fed Pulse Detonation Research Engine written by R. J. Litchford and published by . This book was released on 2001 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Pulse Detonation Engines status and Application written by D. M. Tidd and published by . This book was released on 2005 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thrust Measurement of a Split path Valveless Pulse Detonation Engine written by and published by . This book was released on 2007 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: Theory predicts ideal pulse detonation technology offers significant fuel efficiency advantages over ramjet/scramjet architecture within a range from high subsonic to low hypersonic velocities. In practice, Pulse Detonation Engines (PDE) require implementation of loss-inducing techniques such as turbulence-generation devices to achieve and sustain detonation events, which effectively narrows the efficiency gap between the two technologies. Pressure losses associated with such obstacles lower system specific thrust (Isp) and reduce overall system performance. Although fundamental PDE research has been ongoing at NPS for seven years, no dedicated attempt has been made to accurately measure the experimental performance. Fuel-based Isp is a function of the ratio of thrust produced to fuel mass flow rate; thus, accurate computation requires precise knowledge of both thrust and input fuel. This thesis focused on creating an accurate thrust collection system incorporating an existing, uncalibrated rocket thrust stand. An in depth, axial component thrust calibration was conducted for the stand itself, then with the engine mounted in the firing configuration. As expected, harmonic responses of the stand during detonation experimentation were experienced which required creation and implementation of filtering algorithms to successfully extract useful thrust values.

Download or read book Evaluation of Straight and Swept Ramp Obstacles on Enhancing Deflagration to Detonation Transition in Pulse Detonation Engines written by Carlos A. Medina and published by . This book was released on 2006 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of detonations to achieve thrust in pulse detonation engines (PDEs) offers significant advantages in efficiency, simplicity, and versatility. An enabling mechanism for practical PDE implementation will likely utilize an efficient deflagration-to-detonation transition (DDT) process. This method simplifies detonation generation, but the required length is prohibitive in many applications and limits the frequency of repeatability. Obstacles have historically been employed to minimize the DDT distance, but often result in significant total pressure losses that degrade the delivered efficiency advantages of PDEs. This thesis explored the use of straight and swept ramp obstacles to accelerate DDT while minimizing the overall pressure losses. Computer modeling examined three-dimensional disturbances caused by such obstacles. Experimental tests measured combustion shockwave speed, flame velocity, and flame front interactions with obstacles. Evaluations were completed for several straight ramp obstacle configurations in a modeled two-dimensional flow. The placement of consecutive ramps resulted in flame acceleration accompanied by significant pressure spikes approaching 500 psi. Although detonation was not verified across the instrumented section, experimental data prove that straight ramp obstacles successfully accelerate the DDT process. Computer modeling predicts that swept ramps may be even more effective by introducing streamwise vorticity with a relatively low pressure drop.

Download or read book Applications of Calorimetry written by Jose Luis Rivera Armenta and published by BoD – Books on Demand. This book was released on 2022-06-23 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: Calorimetry is used to measure the transfer and exchange of heat. It is a technique that has applications in different research and industrial sectors. It can be applied in kinetic studies as well as to measure physical changes of first- and second-order transitions such as glass transition, melting, and crystallization. It can also be used to evaluate thermodynamic parameters. This book reports on calorimetry in three sections: “Applications in General”, “Calorimetry in Materials”, and “Calorimetry in Biotechnology”.

Download or read book Confined Detonations and Pulse Detonation Engines written by and published by . This book was released on 2003 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: The current focus on utilizing detonations for air-breathing propulsion has shifted from long-term studies of the possibility of fuel energy transformation in stabilized oblique detonation waves to investigations and practical development of propulsion engines operating on propagating detonations in a pulse mode. Contrary to the oblique-detonation concept that is applicable to hypersonic flight at velocities comparable or higher than the Chapman-Jouguet detonation velocity of the fuel-air mixture, the concept of a pulse detonation engine (PDE) is attractive for both subsonic and supersonic flight with the PDE as a main propulsion unit or as an afterburner in turbojet or turbofan propulsion system. In particular, PDE-based propulsion is attractive for flight Mach number up to about 4. Within this range of Mach number, solid rocket motors are known to be very efficient in terms of simplicity and high-speed capability, but they have a limited powered range. Turbojet and turbofan engines, due to their high specific impulse, provide longer range and heavier payloads, but at flight Mach number exceeding 2-3, they get too expensive. Ramjets and ducted rockets designed for flight Mach number up to 4 require solid rocket boosters to accelerate them to the ramjet take over speed, which increase the complexity and volume of a propulsion system. Combined-cycle engines, such as turborockets or turboramjets, are also very complex and expensive for similar applications.

Download or read book Investigation on Novel Methods to Increase Specific Thrust in Pulse Detonation Engines Via Imploding Detonations written by and published by . This book was released on 2009 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pulse Detonation Engines (PDE) are seen to be the next generation propulsion systems due to enhanced thermodynamic efficiencies based on the Humphrey cycle. One of the limitations in fielding practical designs has been attributed to tube diameters not exceeding 5 inches as the shock wave takes a long run distance for transition to detonation, thus potentially affecting specific thrust. Novel methods via imploding detonations were investigated to remove such limitations. During the study, a practical computational cell size was first determined so as to capture the required physics for transient detonation wave propagation using a Hydrogen-Air test case. Through a grid sensitivity analysis, one-quarter of the induction length was found sufficient to capture the experimentally observed initial wave transients. Test case models utilizing axisymmetric head-on implosions were studied in order to understand how the implosion process reinforces a detonation wave as it expands. This in effect creates localized overdriven regions, which maintains the transition process to full detonation. A parametric study was also performed to determine the extent of diameter increase and it was found that the detonations could be supported with no change in run distance even when the tube diameter exceeds 5 inches.

Download or read book MEMS Based Pulse Detonation Engine for Small scale Propulsion Applications written by K. McManus and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fuel Injection Strategy for a Next Generation Pulse Detonation Engine written by and published by . This book was released on 2006 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Pulse Detonation Engine offers the Department of Defense a new low cost, light weight, and efficient solution to supersonic flight on many of its small airborne platforms. In the past, both liquid fuel and gaseous fuel designs have been partially developed and tested. Several aspects of these configurations have led to the need for the development of a new design, in particular the reduction of total pressure losses, and the removal of auxiliary oxygen system previously required to initiate a detonation wave in fuel-air mixtures within practical distances. Furthermore, higher repetition rates are required for practical thrust levels, as well as the use of liquid fuels, as these are more attractive due to their higher energy densities. A new PDE configuration was designed to operate on the liquid fuel, JP-10. The fuel injection system was characterized using laser diagnostics so that the fuel injection strategy could be optimized for the specified operating conditions. The timing parameters for the fuel-air injection profile were characterized as well in order to deliver the desired amount and duration. This was a concurrent effort with computational simulations of the internal flow paths, design/integration of a novel transient plasma ignition system, and ongoing developments of a performance measurement test rig.

Download or read book Performance and Environmental Impact Assessment of Pulse Detonation Based Engine Systems written by Aaron J. Glaser and published by . This book was released on 2007 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: The acoustic signature of a pulse detonation engine was characterized in both the near-field and far-field regimes. Experimental measurements were performed in an anechoic test facility designed for jet noise testing. Both shock strength and speed were mapped as a function of radial distance and direction from the PDE exhaust plane. It was found that the PDE generated pressure field can be reasonably modeled by a theoretical point-source explosion. The effect of several exit nozzle configurations on the PDE acoustic signature was studies. These included various chevron nozzles, a perforated nozzle, and a set of proprietary noise attenuation mufflers.