Download or read book Active Control of Combustion Instabilities with Real time Observation of Unstable Combustor Modes written by Y. Neumeier and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adaptive Control of Combution Instabilities Using Real time Modes Observation written by Clifford Edgar Johnson and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Combustion instabilities are a significant problem in combustion systems, particularly in Low NOx Gas Turbine combustors. These instabilities result in large-scale pressure oscillations in the combustor, leading to degraded combustor performance, shortened lifetime, and catastrophic combustor failure. The objective of this research was to develop a practical adaptive active control system that, coupled with an appropriate actuator, is capable of controlling the combustor pressure oscillations without a priori knowledge of the combustor design, operating conditions or instability characteristics. The adaptive controller utilizes an observer that determines the frequencies, phases and amplitudes of the dominant modes of the oscillations in real time. The research included development and testing of the adaptive controller on several combustors and on an unstable acoustic feedback system in order to analyze its performance. The research also included investigations of combustor controllability and combustor stability margin, which are critical issues for practical implementation of an active control system on an industrial combustor. The results of this research are directly applicable to a variety of combustors and can be implemented on full-scale industrial combustion systems.
Download or read book Thermoacoustic Combustion Instability Control written by Dan Zhao and published by Academic Press. This book was released on 2023-02-13 with total page 1145 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermoacoustic Combustion Instability Control: Engineering Applications and Computer Codes provides a unique opportunity for researchers, students and engineers to access recent developments from technical, theoretical and engineering perspectives. The book is a compendium of the most recent advances in theoretical and computational modeling and the thermoacoustic instability phenomena associated with multi-dimensional computing methods and recent developments in signal-processing techniques. These include, but are not restricted to a real-time observer, proper orthogonal decomposition (POD), dynamic mode decomposition, Galerkin expansion, empirical mode decomposition, the Lattice Boltzmann method, and associated numerical and analytical approaches. The fundamental physics of thermoacoustic instability occurs in both macro- and micro-scale combustors. Practical methods for alleviating common problems are presented in the book with an analytical approach to arm readers with the tools they need to apply in their own industrial or research setting. Readers will benefit from practicing the worked examples and the training provided on computer coding for combustion technology to achieve useful results and simulations that advance their knowledge and research. Focuses on applications of theoretical and numerical modes with computer codes relevant to combustion technology Includes the most recent modeling and analytical developments motivated by empirical experimental observations in a highly visual way Provides self-contained chapters that include a comprehensive, introductory section that ensures any readers new to this topic are equipped with required technical terms
Download or read book Numerical Simulation and Active Control of Combustion Instability in a Ramjet Combustor written by S. Menon and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Combustion Instabilities in Gas Turbine Engines written by Timothy C. Lieuwen and published by AIAA (American Institute of Aeronautics & Astronautics). This book was released on 2005 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers gas turbine users and manufacturers a valuable resource to help them sort through issues associated with combustion instabilities. In the last ten years, substantial efforts have been made in the industrial, governmental, and academic communities to understand the unique issues associated with combustion instabilities in low-emission gas turbines. The objective of this book is to compile these results into a series of chapters that address the various facets of the problem. The Case Studies section speaks to specific manufacturer and user experiences with combustion instabilities in the development stage and in fielded turbine engines. The book then goes on to examine The Fundamental Mechanisms, The Combustor Modeling, and Control Approaches.
Download or read book 41st AIAA Aerospace Sciences Meeting Exhibit written by and published by . This book was released on 2003 with total page 686 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 34th Aerospace Sciences Meeting Exhibit written by and published by . This book was released on 1996 with total page 692 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ASME Technical Papers written by and published by . This book was released on 2001 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Performance Enhancement of Gas Turbine Combustor by Active Control of Fuel Injection and Mixing Process Theory and Practice written by Christian O. Pascherelt and published by . This book was released on 2001 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unstable thermoacoustic modes were investigated and controlled in an experimental low-emission swirl stabilized combustor, in which the acoustic boundary conditions were modified to obtain combustion instability. Axisymmetric and helical unstable modes wore identified for fully premixed combustion These unstable modes were associated with flow instabilities related to the recirculation region on the combustor axis and shear layer in- stabilities at the sudden expansion (dump plane). The combustion structure associated with the different unstable modes was visualized by phase locked images of OH chemi- luminescence, The axisymmetric mode showed large variation of the heat release during one cycle, while the helical modes showed circumferential variations in the location of maximal heat release. Two feedback control methods employed to suppress thermoa- coustic pressure oscillations and to reduce emissions reviewed: proportional acoustic control and fuel modulations. Microphone sensors monitored the combustion process and provided input to the control systems. An acoustic actuation modulated the airflow and thus affected the mixing process and the combustion. Suppression levels of up to 25 dB in the pressure oscillations and a concomitant 10% reduction of NO(x) emissions were obtained. At the optimal control conditions It was shown that the major effect of the control system was to reduce the coherence of the vortical structures which gave rise to the thermoacoustic instability. The specific design of the investigated experimental burner allowed testing the effect of different modulated fuel injection concepts on the combustion instability modes. Symmetric and antisymmetric fuel injection schemes were tested. Suppression levels of up to 12 dB in the pressure oscillations were observed. In some cases concomitant reductions of NO and CO emissions were obtained.
Download or read book Paper written by and published by . This book was released on 2001 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 38th Aerospace Sciences Meeting and Exhibit written by and published by . This book was released on 2000 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 39th AIAA Aerospace Sciences Meeting and Exhibit written by and published by . This book was released on 2001 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 39th AIAA ASME SAE ASEE Joint Propulsion Conference Exhibit July 20 23 2003 Huntsville Alabama no 4799 written by and published by . This book was released on 2003 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Model based Active Control of Thermoacoustic Instability in Continuous Combustion Processes written by Jennifer Weerts Rumsey and published by . This book was released on 1998 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Combustion Dans Les Turbomoteurs Les missions Et Les Carburants de Remplacement written by North Atlantic Treaty Organization. Research and Technology Organization. Applied Vehicle Technology Panel. Symposium and published by . This book was released on 1999 with total page 622 pages. Available in PDF, EPUB and Kindle. Book excerpt: The symposium dealt with Gas Turbine Engine Combustion, Emissions and Alternative Fuels. Forty-six papers and a Keynote Address elucidated the role of the combustion process as a crucial factor of engine performance and operability under various conditions including non-standard, new fuels and environmental effects of civil and military interest. There were 12 Sessions covering the following topics (some in 2 sessions): (1) Gas Turbines in Land, Sea and Air Applications; (2) Low-Emission Combustors; (3) Combustion Modelling; (4) Optical Measurements; (5) Emissions; (6) Combustor Design; (7) Ignition Processes; (8) Active Combustion Control; and (9) Alternative Fuels.
Download or read book Modeling and Control of Thermoacoustics in a One dimensional Combustor written by Xiaoling Chen and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation examines the model-based optimization of sensor placement, estimation, and control for the active suppression of thermoacoustic instabilities in a one-dimensional combustor. This research is motivated by the increasing use of lean premixed combustion for emission reduction in gas turbine combustors. Thermoacoustic instability is a potentially damaging side effect of lean premixed combustion, caused by the unstable coupling between acoustics and unsteady heat release. There is extensive existing literature on the suppression of this instability, using both passive means such as Helmholtz resonators and active stability control. Much of the work on active combustion stability control relies on the injection of an additional acoustic excitation or fuel supply to break the above undesirable unstable coupling, thereby suppressing instability. Researchers have shown the promise of active combustion instability control both in simulations and laboratory experiments, for both single and multiple modes of instability. Active combustion stability control remains relatively scarce in industrial practice, despite the rich existing literature indicating its potential for success. Several important research questions need to be answered in order to help bridge this gap. First, while much of the recent research on active combustion stability control assumes one-dimensional combustion dynamics, an open question remains regarding the importance of other dynamic effects in the combustor, such as the dynamic interactions between multiple flames. Second, the degree to which the placement of sensors and actuators in a combustor affects the accuracy with which combustion instability dynamics can be estimated remains relatively unexplored in the literature. Third, the suitability of traditional linear model-based estimation and control techniques for stabilizing combustion instabilities with nonlinear heat release dynamics also remains relatively unexplored in the literature. The overarching goal of this dissertation is to address the above gaps using a combination of optimal sensor placement, optimal estimation, and optimal control. Towards this goal, the dissertation makes six specific contributions to the literature: 1. First, the author performs an experimental comparison between thermoacoustic instabilities in single- versus multi-nozzle combustion systems (Chapter 2). This study shows that the dynamic interactions between multiple flames in a multi-nozzle combustor have a non-trivial impact on thermoacoustic instability, especially the time scales of the transient instabilities. This helps characterize and understand the constraints on the practical applicability of one-dimensional combustion instability models for multi-nozzle systems, including the models used in the remainder of this dissertation. 2. Second, the author optimizes the design of a laboratory characterization experiment for a one-dimensional combustor (Chapter 3). This optimization utilizes Fisher information analysis for optimal combustion instability characterization, for the first time. 3. Third, the dissertation shows, using a mix of simulation-based and experimental studies, that the above use of optimal experimental design improves combustion instability parameterization accuracy (Chapter 4). Moreover, by furnishing more accurate combustion instability models, one is able to achieve higher levels of confidence in the robustness of the resulting combustion stability controllers. 4. Fourth, the dissertation presents a novel algorithm that makes it possible to estimate combustion heat release rates from multi-microphone measurements of the resulting acoustic signatures, in a manner that does not require the modeling of heat release dynamics (Chapter 5). This is important because it simplifies the online estimation of heat release dynamics, compared to model-based estimation methods requiring a heat release model. 5. Fifth, the dissertation studies the impact of sensor placement on the observability and LQG control of combustion instabilities governed by a linear $n-\tau$ heat release model (Chapter 6). This work highlights the importance of placing acoustic sensors at specific locations like the pressure mode anti-node points, including the acoustically closed combustor boundary. 6. Finally, the author develops a computational framework for the co-simulation of linear combustor acoustics, model-based combustion stability control, and nonlinear heat release dynamics governed by a level-set solver (Chapter 7). To the best of the author's knowledge, this is the first framework in the literature enabling the simulation-based study of the efficacy of linear control for combustion instabilities characterized by nonlinear heat release dynamics. In making the above contributions to the literature, this dissertation builds on the well-established idea that linear model-based estimation and control can be effective in suppressing combustion instability. The novelty of the dissertation lies in: 1. Pushing the above idea further by examining the degree to which its efficacy can be enhanced further through the use of information theory to optimize sensor placement and experimental design for estimation/control applications. 2. Building a framework that makes it possible to study the efficacy of model-based linear estimation/control in the context of thermo-acoustic instabilities driven by nonlinear heat release dynamics.
Download or read book Feedback Control of Combustion Instabilities written by Anil Gulati and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
