Author: John C. Delaat
Publisher: BiblioGov
Published: 2013-06
Total Pages: 24
ISBN-13: 9781289111984
DOWNLOAD EBOOK →Future aircraft engines must provide ultra-low emissions and high efficiency at low cost while maintaining the reliability and operability of present day engines. The demands for increased performance and decreased emissions have resulted in advanced combustor designs that are critically dependent on efficient fuel/air mixing and lean operation. However, all combustors, but most notably lean-burning low-emissions combustors, are susceptible to combustion instabilities. These instabilities are typically caused by the interaction of the fluctuating heat release of the combustion process with naturally occurring acoustic resonances. These interactions can produce large pressure oscillations within the combustor and can reduce component life and potentially lead to premature mechanical failures. Active Combustion Control which consists of feedback-based control of the fuel-air mixing process can provide an approach to achieving acceptable combustor dynamic behavior while minimizing emissions, and thus can provide flexibility during the combustor design process. The NASA Glenn Active Combustion Control Technology activity aims to demonstrate active control in a realistic environment relevant to aircraft engines by providing experiments tied to aircraft gas turbine combustors. The intent is to allow the technology maturity of active combustion control to advance to eventual demonstration in an engine environment. Work at NASA Glenn has shown that active combustion control, utilizing advanced algorithms working through high frequency fuel actuation, can effectively suppress instabilities in a combustor which emulates the instabilities found in an aircraft gas turbine engine. Current efforts are aimed at extending these active control technologies to advanced ultra-low-emissions combustors such as those employing multi-point lean direct injection.
Author: Marcus H. Richman
Publisher:
Published: 2001
Total Pages: 8
ISBN-13:
DOWNLOAD EBOOK →The U.S. Navy, as a participant in the United States' Integrated High Performance Turbine Engine Technology (IHPTET) initiative, is dedicated to increasing aircraft engine performance to satisfy the propulsion requirements of future Navy aircraft. This is accomplished by identifying the propulsion requirements, in terms of performance and total cost, for specific Navy aircraft. The required engine technology advances are then broken down into specific engine component technology objectives. Advanced technology is then developed on the component level. Once an appropriate level of readiness is reached, the components are then assembled into an engine for overall advanced propulsion system demonstration. Technologies from this demonstrator engine are then made available to development engine programs, such as the Joint Strike Fighter (JSF), for further development and eventual transition to production engine programs.
Author: Rudibert King
Publisher: Springer Nature
Published: 2021-11-12
Total Pages: 359
ISBN-13: 3030907279
DOWNLOAD EBOOK →The book reports on the latest theoretical and experimental findings in the field of active flow and combustion control, in the context of energy conversion for power and propulsion systems. It covers new developments in actuator technology and sensing, robust and optimal open- and closed-loop control, model reduction for control purposes, and unsteady turbine cooling and performance, among other relevant topics. Gathering contributions to the Active Flow and Combustion Control (AFCC 2021), held virtually on September 28-29, 2021, from the Technische Universität Berlin, Germany, this book describes research that has been carried out within, and supported by, the collaborative research center SFB 1029 on “Substantial efficiency increase in gas turbines through direct use of coupled unsteady combustion and flow dynamics”, and funded by the German Research Foundation (DFG). It highlights theoretical and practical aspects, and corresponding solutions, that are important for the development of future energy conversion systems, thus offering a timely guide for researchers and practitioners in the field of aeronautics, turbomachinery, control and combustion.
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
Published: 2018-06-20
Total Pages: 30
ISBN-13: 9781721588237
DOWNLOAD EBOOK →Active control of high-frequency (greater than 500 Hz) combustion instability has been demonstrated in the NASA single-nozzle combustor rig at United Technologies Research Center. The combustor rig emulates an actual engine instability and has many of the complexities of a real engine combustor (i.e. actual fuel nozzle and swirler, dilution cooling, etc.) In order to demonstrate control, a high-frequency fuel valve capable of modulating the fuel flow at up to 1kHz was developed. Characterization of the fuel delivery system was accomplished in a custom dynamic flow rig developed for that purpose. Two instability control methods, one model-based and one based on adaptive phase-shifting, were developed and evaluated against reduced order models and a Sectored-1-dimensional model of the combustor rig. Open-loop fuel modulation testing in the rig demonstrated sufficient fuel modulation authority to proceed with closed-loop testing. During closed-loop testing, both control methods were able to identify the instability from the background noise and were shown to reduce the pressure oscillations at the instability frequency by 30%. This is the first known successful demonstration of high-frequency combustion instability suppression in a realistic aero-engine environment. Future plans are to carry these technologies forward to demonstration on an advanced low-emission combustor. Corrigan, Bob (Technical Monitor) and DeLaat, John C. and Chang, Clarence T. Glenn Research Center NASA/TM-2003-212611, E-14169, NAS 1.15:212611, ISABE-2003-1054
Author: Rudibert King
Publisher: Springer
Published: 2018-09-03
Total Pages: 380
ISBN-13: 3319981773
DOWNLOAD EBOOK →The book reports on the latest theoretical and experimental findings in the field of active flow and combustion control. It covers new developments in actuator technology and sensing, in robust and optimal open- and closed-loop control, as well as in model reduction for control, constant volume combustion and dynamic impingement cooling. The chapters reports oncutting-edge contributions presented during the fourth edition of the Active Flow and Combustion Control conference, held in September 19 to 21, 2018 at the Technische Universität Berlin, in Germany. This conference, as well as the research presented in the book, have been supported by the collaborative research center SFB 1029 on “Substantial efficiency increase in gas turbines through direct use of coupled unsteady combustion and flow dynamics”, funded by the DFG (German Research Foundation). It offers a timely guide for researchers and practitioners in the field of aeronautics, turbomachinery, control and combustion.