Download or read book Performance of a Boundary Layer Ingesting Propulsion System written by Angélique Pascale Plas and published by . This book was released on 2006 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) In terms of qualitative information, the three models are found to give broadly similar trends for distortion attenuation and for fuel burn benefit. In terms of quantitative results, the body force analysis shows that for a fan diameter and flight condition representative of that employed in the Cambridge-MIT Institute "Silent Aircraft" boundary layer ingestion can provide decreases in fuel burn of up to 3.8 percent.
Download or read book A Tail integrated Boundary layer Ingesting Propulsion System for Turbo electric Aircraft written by Zhibo Chen (Aeronautics researcher) and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, we present conceptual design guidelines and results for a tail-integrated propulsion system for turbo-electric aircraft with boundary layer ingestion (BLI). This includes (i) definition of tail BLI electric fans and (ii) integration of the BLI propulsors on an aircraft tail, to meet the propulsive power requirements and performance goals, i.e. separation-free and shock-free operation with fuel burn reduction, compared with a baseline aircraft for the same mission. The assessment of BLI benefits incorporates CFD and TASOPT analyses, with emphasis placed on utilizing these analyses not only to identify potential challenges for integration of the BLI propulsors, but also to characterize the underlying mechanisms and thus establish the physical rationale for resolving these challenges. The conceptual design resulting from the guidelines has nine BLI propulsors with electric fans on an axisymmetric tail, which is installed on a baseline single-aisle aircraft with twin underwing turbofans without BLI. For the tail-integrated BLI electric fans, the guidelines include the required fan loss buckets, and non-axisymmetric stators, to mitigate the fan efficiency drop due to rotor inlet incidence distortion. The design of the tail-integrated propulsor illustrates the aerodynamics of the propulsor inlet, nacelle, and nozzle that enable separation-free and shock-free operation at the cruise condition. The benefit of the defined tail BLI and twin underwing turbofan aircraft configuration is 10.4% in Propulsion Fuel Energy Intensity (PFEI) at a cruise Mach number of 0.8 and an altitude of 35100 ft, compared to a baseline twin underwing turbofan configuration. The sensitivity study shows that a 1% increase in installed (i.e. with BLI) fan efficiency translates to 0.8% rise in the PFEI benefit.
Download or read book The Effect of Incoming Boundary Layer Characteristics on the Performance of a Distributed Propulsion System written by Puja Upadhyay and published by . This book was released on 2019 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Power Based Study of Boundary Layer Ingestion for Aircraft Application written by Peijian Lv and published by Springer Nature. This book was released on 2022-09-14 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents research on Boundary Layer Ingestion (BLI). BLI is an aircraft-engine integration technique that aims at integrating the aircraft and the propulsion system such that the overall aircraft fuel consumption can be reduced. In this research, theoretical analysis suggests that the minimization of total power consumption should be used as a design criterion for aircraft utilizing BLI rather than focusing on the minimization of drag. Numerical simulations are performed, and the simulation results are processed using the PBM to support the theoretical analysis. Furthermore, an experimental study is carried out with a focus on the power conversion processes involved for a propulsor operating in the wake. Stereoscopic PIV is employed in order to visualize the flow and understand the physics. The so-called Power-based Method is used to quantify the power conversion mechanisms. The results prove that the dominant mechanism responsible for the efficiency enhancement is due to the utilization of body wake energy by the wake ingesting propeller. In short, the importance of wake energy flow rate in understanding the BLI phenomenon is highlighted. This book will be useful for researchers in the field of aircraft propulsion, aircraft aerodynamics, and airframe propulsion integration.
Download or read book Commercial Aircraft Propulsion and Energy Systems Research written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2016-08-09 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary human activities that release carbon dioxide (CO2) into the atmosphere are the combustion of fossil fuels (coal, natural gas, and oil) to generate electricity, the provision of energy for transportation, and as a consequence of some industrial processes. Although aviation CO2 emissions only make up approximately 2.0 to 2.5 percent of total global annual CO2 emissions, research to reduce CO2 emissions is urgent because (1) such reductions may be legislated even as commercial air travel grows, (2) because it takes new technology a long time to propagate into and through the aviation fleet, and (3) because of the ongoing impact of global CO2 emissions. Commercial Aircraft Propulsion and Energy Systems Research develops a national research agenda for reducing CO2 emissions from commercial aviation. This report focuses on propulsion and energy technologies for reducing carbon emissions from large, commercial aircraftâ€" single-aisle and twin-aisle aircraft that carry 100 or more passengersâ€"because such aircraft account for more than 90 percent of global emissions from commercial aircraft. Moreover, while smaller aircraft also emit CO2, they make only a minor contribution to global emissions, and many technologies that reduce CO2 emissions for large aircraft also apply to smaller aircraft. As commercial aviation continues to grow in terms of revenue-passenger miles and cargo ton miles, CO2 emissions are expected to increase. To reduce the contribution of aviation to climate change, it is essential to improve the effectiveness of ongoing efforts to reduce emissions and initiate research into new approaches.
Download or read book Analysis of Civil Aircraft Propulsors with Boundary Layer Ingestion written by David Kenneth Hall and published by . This book was released on 2015 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes (i) guidelines for propulsor sizing, and (ii) strategies for fan turbomachinery conceptual design, for a boundary layer ingesting (BLI) propulsion system for advanced civil transport aircraft. For the former, configuration performance analysis shows BLI yields a reduction in mechanical power required to propel a given aircraft. For the latter, fan turbomachinery design attributes are identified to mitigate the impact of BLI inlet distortion on propulsor performance. The propulsion system requirements are determined using a mechanical energy analysis, in which the performance of the airframe and propulsor are characterized in terms of sources and sinks of power. Using this framework, the propulsor can be sized based on the performance of the isolated airframe. Analysis of the power savings due to BLI (from reduction of viscous dissipation both in the aircraft wake and the propulsor jet) leads to scaling choices for the sizing of propulsor simulators for wind tunnel experiments to assess BLI benefit. Fan stage distortion response is assessed computationally for a range of turbomachinery design parameters and for distortions characteristic of BLI. The numerical results show the importance of three-dimensional flow redistribution upstream of the fan, and indicate that, for the parameters examined, non-axisymmetric fan stators have the largest effect on decreasing blade row velocity distortions and thus mitigating losses due to flow non-uniformity.
Download or read book Analysis and Evaluation of an Integrated Laminar Flow Control Propulsion System written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-10-26 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reduction of drag has been a major goal of the aircraft industry as no other single quantity influences the operating costs of transport aircraft more than aerodynamic drag. It has been estimated that even modest reduction of frictional drag could reduce fuel costs by anywhere from 2 to 5 percent. Current research on boundary layer drag reduction deals with various approaches to reduce turbulent skin friction drag as a means of improving aircraft performance. One of the techniques belonging to this category is laminar flow control in which extensive regions of laminar flow are maintained over aircraft surfaces by delaying transition to turbulence through the ingestion of boundary layer air. While problems of laminar flow control have been studied in some detail, the prospect of improving the propulsion system of an aircraft by the use of ingested boundary layer air has received very little attention. An initial study for the purpose of reducing propulsion system requirements by utilizing the kinetic energy of boundary layer air was performed in the mid-1970's at LeRC. This study which was based on ingesting the boundary layer air at a single location, did not yield any significant overall propulsion benefits; therefore, the concept was not pursued further. However, since then it has been proposed that if the boundary layer air were ingested at various locations on the aircraft surface instead of just at one site, an improvement in the propulsion system might be realized. The present report provides a review of laminar flow control by suction and focuses on the problems of reducing skin friction drag by maintaining extensive regions of laminar flow over the aircraft surfaces. In addition, it includes an evaluation of an aircraft propulsion system that is augmented by ingested boundary layer air. Keith, Theo G., Jr. and Dewitt, Kenneth J. Unspecified Center
Download or read book Internal Flow written by E. M. Greitzer and published by Cambridge University Press. This book was released on 2007-02-26 with total page 739 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the analysis and behaviour of internal flows encountered in propulsion systems, fluid machinery (compressors, turbines and pumps) and ducts (diffusers, nozzles and combustion chambers). The focus is on phenomena that are important in setting the performance of a broad range of fluid devices. The authors show that even for complex processes one can learn a great deal about the behaviour of such devices from a clear understanding and rigorous use of basic principles. Throughout the book they illustrate theoretical principles by reference to technological applications. The strong emphasis on fundamentals, however, means that the ideas presented can be applied beyond internal flow to other types of fluid motion. The book equips students and practising engineers with a range of new analytical tools. These tools offer enhanced interpretation and application of both experimental measurements and the computational procedures that characterize modern fluids engineering.
Download or read book Computational Investigation of a Boundary layer Ingestion Propulsion System for the Common Research Model written by Brennan Blumenthal and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis will examine potential propulsive and aerodynamic benefits of integrating a Boundary-layer Ingestion (BLI) propulsion system with a typical commercial aircraft using the Common Research Model geometry and the NASA Tetrahedral Unstructured Software System (TetrUSS). The Numerical Propulsion System Simulation (NPSS) environment will be used to generate engine conditions for CFD analysis. Improvements to the BLI geometry will be made using the Constrained Direct Iterative Surface Curvature (CDISC) design method. Previous studies have shown reductions of up to 25% in terms of propulsive power required for cruise for other axisymmetric geometries using the BLI concept. An analysis of engine power requirements, drag, and lift coefficients using the baseline and BLI geometries coupled with the NPSS model are shown. Potential benefits of the BLI system relating to cruise propulsive power are quantified using a power balance method and a comparison to the baseline case is made. Iterations of the BLI geometric design are shown and any improvements between subsequent BLI designs presented. Simulations are conducted for a cruise flight condition of Mach 0.85 at an altitude of 38,500 feet and an angle of attack of 2° for all geometries. A comparison between available wind tunnel data, previous computational results, and the original CRM model is presented for model verification purposes along with full results for BLI power savings. Results indicate a 14.3% reduction in engine power requirements at cruise for the BLI configuration over the baseline geometry. Minor shaping of the aft portion of the fuselage using CDISC has been shown to increase the benefit from boundary-layer ingestion further, resulting in a 15.6% reduction in power requirements for cruise as well as a drag reduction of eighteen counts over the baseline geometry.
Download or read book Introduction to the Theory of Flow Machines written by Albert Betz and published by Elsevier. This book was released on 2014-05-16 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction to the Theory of Flow Machines details the fundamental processes and the relations that have a significant influence in the operating mechanism of flow machines. The book first covers the general consideration in flow machines, such as pressure, stress, and cavitation. In the second chapter, the text deals with ducts; this chapter discusses the general remarks, types of flow, and mixing process. Next, the book tackles the types of cascades, along with its concerns. The closing chapter covers the flow machine and its components, such as turbine, wheels, engines, and propellers. The text will be of great use to mechanical engineers and technicians.
Download or read book Aerial Robots written by Omar D Lopez Mejia and published by BoD – Books on Demand. This book was released on 2017-09-06 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Few years ago, the topic of aerial robots was exclusively related to the robotics community, so a great number of books about the dynamics and control of aerial robots and UAVs have been written. As the control technology for UAVs advances, the great interaction that exists between other systems and elements that are as important as control such as aerodynamics, energy efficiency, acoustics, structural integrity, and applications, among others has become evident. Aerial Robots - Aerodynamics, Control, and Applications is an attempt to bring some of these topics related to UAVs together in just one book and to look at a selection of the most relevant problems of UAVs in a broader engineering perspective.
Download or read book Distributed Propulsion Technology written by Amir S. Gohardani and published by Nova Science Publishers. This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Distributed propulsion technology is one of the revolutionary candidates for future aircraft propulsion. In this book, which serves as the very first reference book on distributed propulsion technology, the potential role of distributed propulsion technology in future aviation is investigated. Following a historical journey that revisits distributed propulsion technology in unmanned air vehicles, commercial aircrafts, and military aircrafts, features of this specific technology are highlighted in synergy with an electric aircraft concept and a first-of-its-kind comparison between commercial and military aircrafts employing distributed propulsion arrangements. In light of propulsionairframe integration and complementary technologies, such as boundary layer ingestion, thrust vectoring and circulation control, transpired opportunities and challenges are addressed in addition to a number of identified research directions proposed for future aircrafts. Moreover, a diverse set of distributed propulsion arrangements are considered. These include: small engines, gas-driven multi-fan architectures, turboelectric systems featuring superconductive and non-superconducting electrical machine technology, and electromagnetic fans. This book features contributions by the National Aeronautics and Space Administration (NASA) and the United States Air Force (USAF), and includes the first proposed official definition for distributed propulsion technology in subsonic fixed wing aircrafts.
Download or read book Low Speed Wind Tunnel Testing written by Jewel B. Barlow and published by John Wiley & Sons. This book was released on 1999-02-22 with total page 738 pages. Available in PDF, EPUB and Kindle. Book excerpt: A brand-new edition of the classic guide on low-speed wind tunnel testing While great advances in theoretical and computational methods have been made in recent years, low-speed wind tunnel testing remains essential for obtaining the full range of data needed to guide detailed design decisions for many practical engineering problems. This long-awaited Third Edition of William H. Rae, Jr.'s landmark reference brings together essential information on all aspects of low-speed wind tunnel design, analysis, testing, and instrumentation in one easy-to-use resource. Written by authors who are among the most respected wind tunnel engineers in the world, this edition has been updated to address current topics and applications, and includes coverage of digital electronics, new instrumentation, video and photographic methods, pressure-sensitive paint, and liquid crystal-based measurement methods. The book is organized for quick access to topics of interest, and examines basic test techniques and objectives of modeling and testing aircraft designs in low-speed wind tunnels, as well as applications to fluid motion analysis, automobiles, marine vessels, buildings, bridges, and other structures subject to wind loading. Supplemented with real-world examples throughout, Low-Speed Wind Tunnel Testing, Third Edition is an indispensable resource for aerospace engineering students and professionals, engineers and researchers in the automotive industries, wind tunnel designers, architects, and others who need to get the most from low-speed wind tunnel technology and experiments in their work.
Download or read book Airplane Aerodynamics and Performance written by Jan Roskam and published by DARcorporation. This book was released on 1997 with total page 748 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Jet Propulsion written by N. A. Cumpsty and published by Cambridge University Press. This book was released on 2003-08-14 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the second edition of Cumpsty's excellent self-contained introduction to the aerodynamic and thermodynamic design of modern civil and military jet engines. Through two engine design projects, first for a new large passenger aircraft, and second for a new fighter aircraft, the text introduces, illustrates and explains the important facets of modern engine design. Individual sections cover aircraft requirements and aerodynamics, principles of gas turbines and jet engines, elementary compressible fluid mechanics, bypass ratio selection, scaling and dimensional analysis, turbine and compressor design and characteristics, design optimization, and off-design performance. The book emphasises principles and ideas, with simplification and approximation used where this helps understanding. This edition has been thoroughly updated and revised, and includes a new appendix on noise control and an expanded treatment of combustion emissions. Suitable for student courses in aircraft propulsion, but also an invaluable reference for engineers in the engine and airframe industry.
Download or read book Conceptual Design of Propulsion Systems for Boundary Layer Ingestion written by and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book To Life written by Linda Weintraub and published by Univ of California Press. This book was released on 2012-09-01 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: This title documents the burgeoning eco art movement from A to Z, presenting a panorama of artistic responses to environmental concerns, from Ant Farms anti-consumer antics in the 1970s to Marina Zurkows 2007 animation that anticipates the havoc wreaked upon the planet by global warming.
