Blended Wing Body (Bwb) Boundary Layer Ingestion (Bli) Inlet Configuration and System Studies


Book Description

A study was conducted to determine the potential reduction in fuel burned for BLI (boundary layer ingestion) inlets on a BWB (blended wing body) airplane employing AFC (active flow control). The BWB is a revolutionary type airplane configuration with engines on the aft upper surface where thick boundary layer offers the greatest opportunity for ram drag reduction. AFC is an emerging technology for boundary layer control. Several BLI inlet configurations were analyzed in the NASA-developed RANS Overflow CFD code. The study determined that, while large reductions in ram drag result from BLI, lower inlet pressure recovery produces engine performance penalties that largely offset this ram drag reduction. AFC could, however, enable a short BLI inlet that allows surface mounting of the engine which, when coupled with a short diffuser, would significantly reduce drag and weight for a potential 10% reduction in fuel burned. Continuing studies are therefore recommended to achieve this reduction in fuel burned considering the use of more modest amounts of BLI coupled with both AFC and PFC (Passive Flow Control) to produce a fail-operational system. Kawai, Ronald T. and Friedman, Douglas M. and Serrano, Leonel Langley Research Center NASA/CR-2006-214534




Power-Based Study of Boundary Layer Ingestion for Aircraft Application


Book Description

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.




Green Aviation


Book Description

Green Aviation is the first authoritative overview of both engineering and operational measures to mitigate the environmental impact of aviation. It addresses the current status of measures to reduce the environmental impact of air travel. The chapters cover such items as: Engineering and technology-related subjects (aerodynamics, engines, fuels, structures, etc.), Operations (air traffic management and infrastructure) Policy and regulatory aspects regarding atmospheric and noise pollution. With contributions from leading experts, this volume is intended to be a valuable addition, and useful resource, for aerospace manufacturers and suppliers, governmental and industrial aerospace research establishments, airline and aviation industries, university engineering and science departments, and industry analysts, consultants, and researchers.







Distributed Propulsion Technology


Book Description

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.




Aerial Robots


Book Description

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.




Propulsion and Power


Book Description

The book is written for engineers and students who wish to address the preliminary design of gas turbine engines, as well as the associated performance calculations, in a practical manner. A basic knowledge of thermodynamics and turbomachinery is a prerequisite for understanding the concepts and ideas described. The book is also intended for teachers as a source of information for lecture materials and exercises for their students. It is extensively illustrated with examples and data from real engine cycles, all of which can be reproduced with GasTurb (TM). It discusses the practical application of thermodynamic, aerodynamic and mechanical principles. The authors describe the theoretical background of the simulation elements and the relevant correlations through which they are applied, however they refrain from detailed scientific derivations.




Journal of Aircraft


Book Description




The Proceedings of the 2021 Asia-Pacific International Symposium on Aerospace Technology (APISAT 2021), Volume 1


Book Description

This proceeding comprises peer-reviewed papers of the 2021 Asia-Pacific International Symposium on Aerospace Technology (APISAT 2021), held from 15-17 November 2021 in Jeju, South Korea. This book deals with various themes on computational fluid dynamics, wind tunnel testing, flow visualization, UAV design, flight simulation, satellite attitude control, aeroelasticity and control, combustion analysis, fuel injection, cooling systems, spacecraft propulsion and so forth. So, this book can be very helpful not only for the researchers of universities and academic institutes, but also for the industry engineers who are interested in the current and future advanced topics in aerospace technology.




Internal Flow


Book Description

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.