Download or read book Airfoil Dynamic Stall and Rotorcraft Maneuverability written by and published by . This book was released on 2000 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: The loading of an airfoil during dynamic stall is examined in terms of the augmented lift and the associated penalties in pitching moment and drag. It is shown that once stall occurs and a leading-edge vortex is shed from the airfoil there is a unique relationship between the augmented lift, the negative pitching moment, and the increase in drag. This relationship, referred to here as the dynamic stall function, shows limited sensitivity to effects such as the airfoil section profile and Mach number, and appears to be independent of such parameters as Reynolds number, reduced frequency, and blade sweep. For single-element airfoils there is little that can be done to improve rotorcraft maneuverability except to provide good static clmax characteristics and the chord or blade number that is required to provide the necessary rotor thrust. However, multi-element airfoils or airfoils with variable geometry features can provide augmented lift in some cases that exceeds that available from a single-element airfoil. The dynamic stall function is shown to be a useful tool for the evaluation of both measured and calculated dynamic stall characteristics of singleelement, multi-element, and variable geometry airfoils.

Download or read book Annual Department of Defense Bibliography of Logistics Studies and Related Documents written by United States. Defense Logistics Studies Information Exchange and published by . This book was released on 1988 with total page 1120 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book UH 60A Airloads Catalog written by William G. Bousman and published by . This book was released on 2005 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Journal of the American Helicopter Society written by American Helicopter Society and published by . This book was released on 1998 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aeronautical Engineering written by and published by . This book was released on 1986 with total page 888 pages. Available in PDF, EPUB and Kindle. Book excerpt: A selection of annotated references to unclassified reports and journal articles that were introduced into the NASA scientific and technical information system and announced in Scientific and technical aerospace reports (STAR) and International aerospace abstracts (IAA)

Download or read book NASA SP written by and published by . This book was released on 1962 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Encyclopedia of Modern U S Military Weapons written by Timothy M. Laur and published by Berkley Trade. This book was released on 1998-07 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: An accessible encyclopedia of military weapons represents a collaboration with The Army, Navy, and Air Force Times, and covers each weapon system, its evolution, development, and combat experience.

Download or read book Flight Test Identification and Simulation of a UH 60A Helicopter and Slung Load written by and published by . This book was released on 2001 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: Helicopter slung-load operations are common in both military and civil contexts. Helicopters and loads are often qualified for these operations by means of flight tests, which can be expensive and time consuming. There is significant potential to reduce such costs both through revisions in flight-test methods and by using validated simulation models. To these ends, flight tests were conducted at Moffett Field to demonstrate the identification of key dynamic parameters during flight tests (aircraft stability margins and handling-qualities parameters, and load pendulum stability), and to accumulate a data base for simulation development and validation. The test aircraft was a UH-60A Black Hawk, and the primary test load was an instrumented 8- by 6- by 6-ft cargo container. Tests were focused on the lateral and longitudinal axes, which are the axes most affected by the load pendulum modes in the frequency range of interest for handling qualities; tests were conducted at airspeeds from hover to 80 knots. Using telemetered data, the dynamic parameters were evaluated in near real time after each test airspeed and before clearing the aircraft to the next test point. These computations were completed in under 1 min. A simulation model was implemented by integrating an advanced model of the UH-60A aerodynamics, dynamic equations for the two-body slung-load system, and load static aerodynamics obtained from wind-tunnel measurements. Comparisons with flight data for the helicopter alone and with a slung load showed good overall agreement for all parameters and test points; however, unmodeled secondary dynamic losses around 2 Hz were found in the helicopter model and they resulted in conservative stability margin estimates.

Download or read book Flight Testing and Real Time System Identification Analysis of a Uh 60a Black Hawk Helicopter with an Instrumented External Sling Load written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-06 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Helicopter external air transportation plays an important role in today's world. For both military and civilian helicopters, external sling load operations offer an efficient and expedient method of handling heavy, oversized cargo. With the ability to reach areas otherwise inaccessible by ground transportation, helicopter external load operations are conducted in industries such as logging, construction, and fire fighting, as well as in support of military tactical transport missions. Historically, helicopter and load combinations have been qualified through flight testing, requiring considerable time and cost. With advancements in simulation and flight test techniques there is potential to substantially reduce costs and increase the safety of helicopter sling load certification. Validated simulation tools make possible accurate prediction of operational flight characteristics before initial flight tests. Real time analysis of test data improves the safety and efficiency of the testing programs. To advance these concepts, the U.S. Army and NASA, in cooperation with the Israeli Air Force and Technion, under a Memorandum of Agreement, seek to develop and validate a numerical model of the UH-60 with sling load and demonstrate a method of near real time flight test analysis. This thesis presents results from flight tests of a U.S. Army Black Hawk helicopter with various external loads. Tests were conducted as the U.S. first phase of this MOA task. The primary load was a container express box (CONEX) which contained a compact instrumentation package. The flights covered the airspeed range from hover to 70 knots. Primary maneuvers were pitch and roll frequency sweeps, steps, and doublets. Results of the test determined the effect of the suspended load on both the aircraft's handling qualities and its control system's stability margins. Included were calculations of the stability characteristics of the load's pendular motion. Utilizing CIFER(R) software, a method for near-...

Download or read book The Final Report of the Fact Finding Commission pursuant to R A No 6832 written by Philippines. Fact-Finding Commission and published by . This book was released on 1990 with total page 644 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Flight Testing and Real Time System Identification Analysis of a UH 60A Black Hawk Helicopter with an Instrumented External Sling Load written by Allen H. McCoy and published by . This book was released on 1997-12 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: Historically, helicopter and load combinations have been qualified through flight testing, requiring considerable time and cost. With advancements in simulation and flight test techniques, there is potential to substantially reduce costs and increase the safety of helicopter sling load certification. Validated simulation tools make possible accurate prediction of operational flight characteristics before initial flight tests. Real time analysis of test data improves the safety and efficiency of the testing programs. To advance these concepts, the US Army and NASA, in cooperation with the Israeli Air Force and Technion, under a Memorandum of Agreement, seek to develop and validate a numerical model of the UH-60 with sling load and demonstrate a method of near real time flight test analysis. This thesis presents results from flight tests of a US Army Black Hawk helicopter with various external loads. Tests were conducted as the US first phase of this MOA task. The primary load was a container express box (CONEX), which contained a compact instrumentation package. The flights covered the airspeed range from hover to 70 knots. Primary maneuvers were pitch and roll frequency sweeps, steps, and doublets. Results of the test determined the effect of the suspended load on both the aircraft's handling qualities and it's control system's stability margins. Included were calculations of the stability characteristics of the load's pendular motion. Utilizing CIFER software, a method for near-real time system identification was also demonstrated during the flight test program.

Download or read book United States Armed Forces Medical Journal written by and published by . This book was released on 1951 with total page 990 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Army RD A written by and published by . This book was released on 1987 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Navy Times Book of Submarines written by Brayton Harris and published by Berkley Hardcover. This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shattering long-held myths and misunderstandings, author Brayton Harris traces the development of the submarine through an era in which writers of fiction saw the merits better than most professionals -- until the Germans almost won World War I. He covers the professional and political arrogance that delayed antisubmarine development for so long that German submarines almost won World War II as well, and examines post-war progress toward the truly awesome submarine of today. Along the way, Harris explores the shifting moral issues of "unrestricted" naval warfare, outlines the hundred-year search for an effective underwater power plant that culminated in the nuclear reactor, and raises important questions about the future. A fascinating exploration of the steps and stumbles during development, a rousing tribute to those who fought and died, and a powerful study of the submarine's impact on America, The Navy Times Book of Submarines is an unparalleled source for understanding the great "hunters of the deep".

Download or read book Fuel for the Flame written by Alec Waugh and published by A&C Black. This book was released on 2011-10-28 with total page 557 pages. Available in PDF, EPUB and Kindle. Book excerpt: First published in 1960, this is a tale of an imaginary island on the Equator that has suddenly achieved importance through the discovery of oil - what will happen to the men and women living under the tensions of life on this island? At one end of this island is the oil refinery where the members of the staff live in constant proximity to one another, and where emotions are heightened by the lack of privacy. The men are goaded by ambitions for power, while the women are drawn into affairs of love and passion. At the other end of the island is a hotbed of politics where a British diplomat is attempting to retain the island under Britain's sphere of influence; where an ailing king is fearful of what will happen when he is succeeded by a young and untrained prince; where a nationalist group is plotting to overthrow the monarchy and seize the oil fields. Waugh handles brilliantly his political plots, but always interwoven with them are the personal dramas of love and fear, of cowardice and courage. Rich in detail and characterisation, and in the exotic colours and customs of this strange land, the novel has constant suspense and variety.

Download or read book The Deming Route to Quality and Productivity written by William W. Scherkenbach and published by Ceep Press Books. This book was released on 1986 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a collection of the author's observations, ideas, and interpretations of Dr. Deming's philosophy.

Download or read book USAF Weapons Review written by and published by . This book was released on 1993 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: