An Analytical Model for the Impulse of a Single-cycle Pulse Detonation Engine

An Analytical Model for the Impulse of a Single-cycle Pulse Detonation Engine PDF Author: E. Wintenberger
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Category :
Languages : en
Pages :

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An Analytical Model for the Impulse of a Single-cycle Pulse Detonation Engine

An Analytical Model for the Impulse of a Single-cycle Pulse Detonation Engine PDF Author: E. Wintenberger
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Gasdynamic Phenomena and Propulsive Performance of Pulse Detonation Engines

Gasdynamic Phenomena and Propulsive Performance of Pulse Detonation Engines PDF Author: James T. Peace
Publisher:
ISBN:
Category : Aerospace engineering
Languages : en
Pages : 312

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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.

Combustion Processes in Propulsion

Combustion Processes in Propulsion PDF Author: Gabriel Roy
Publisher: Butterworth-Heinemann
ISBN: 0123693942
Category : Business & Economics
Languages : en
Pages : 505

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Book Description
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

Detonation Control for Propulsion

Detonation Control for Propulsion PDF Author: Jiun-Ming Li
Publisher: Springer
ISBN: 3319689061
Category : Technology & Engineering
Languages : en
Pages : 246

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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.

40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit July 11-14, 2004, Fort Lauderdale, FL.: 04-3700 - 04-3749

40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit July 11-14, 2004, Fort Lauderdale, FL.: 04-3700 - 04-3749 PDF Author:
Publisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 510

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Impulse Measurements and Analytical Studies on a Cyclic Pulse Detonation Engine

Impulse Measurements and Analytical Studies on a Cyclic Pulse Detonation Engine PDF Author: Y. Matsutomi
Publisher:
ISBN:
Category :
Languages : en
Pages :

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37th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit

37th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit PDF Author:
Publisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 538

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Shock Waves

Shock Waves PDF Author: Klaus Hannemann
Publisher: Springer Science & Business Media
ISBN: 3540851682
Category : Science
Languages : en
Pages : 810

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Book Description
The 26th International Symposium on Shock Waves in Göttingen, Germany was jointly organised by the German Aerospace Centre DLR and the French-German Research Institute of Saint Louis ISL. The year 2007 marked the 50th anniversary of the Symposium, which first took place in 1957 in Boston and has since become an internationally acclaimed series of meetings for the wider Shock Wave Community. The ISSW26 focused on the following areas: Shock Propagation and Reflection, Detonation and Combustion, Hypersonic Flow, Shock Boundary Layer Interaction, Numerical Methods, Medical, Biological and Industrial Applications, Richtmyer Meshkov Instability, Blast Waves, Chemically Reacting Flows, Diagnostics, Facilities, Flow Visualisation, Ignition, Impact and Compaction, Multiphase Flow, Nozzles Flows, Plasmas and Propulsion. The two Volumes contain the papers presented at the symposium and serve as a reference for the participants of the ISSW 26 and individuals interested in these fields.

Advances in Design, Simulation and Manufacturing III

Advances in Design, Simulation and Manufacturing III PDF Author: Vitalii Ivanov
Publisher: Springer Nature
ISBN: 3030504913
Category : Technology & Engineering
Languages : en
Pages : 418

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Book Description
This book explores topics at the interface between mechanical and chemical engineering, with a focus on design, simulation, and manufacturing. Covering recent developments in the mechanics of solids and structures; numerical simulation of coupled problems, including wearing, compression, detonation and collision; and chemical process technologies, including ultrasonic technology, capillary rising process, pneumatic classification, membrane electrolysis and absorption processes, it reports on developments in the field of heat and mass transfer, energy-efficient technologies, and industrial ecology. Part of a two-volume set based on the 3rd International Conference on Design, Simulation, Manufacturing: The Innovation Exchange (DSMIE-2020), held on June 9-12, 2020, in Kharkiv, Ukraine, this book provides academics and professionals with extensive information on the latest trends, technologies and challenges in the field as well as practical lessons learned.

40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit July 11-14, 2004, Fort Lauderdale, FL.: 04-3400 - 04-3449

40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit July 11-14, 2004, Fort Lauderdale, FL.: 04-3400 - 04-3449 PDF Author:
Publisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 570

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Book Description