Download or read book Noise Generated by a Flight Weight Air Flow Control Valve in a Vertical Takeoff and Landing Aircraft Thrust Vectoring System written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-10 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tests were conducted in the NASA Lewis Research Center's Powered Lift Facility to experimentally evaluate the noise generated by a flight weight, 12 in. butterfly valve installed in a proposed vertical takeoff and landing thrust vectoring system. Fluctuating pressure measurements were made in the circular duct upstream and downstream of the valve. This data report presents the results of these tests. The maximum overall sound pressure level is generated in the duct downstream of the valve and reached a value of 180 dB at a valve pressure ratio of 2.8. At the higher valve pressure ratios the spectra downstream of the valve is broad banded with its maximum at 1000 Hz. Huff, Ronald G. Unspecified Center...
Download or read book Noise Generated by a Flight Weight Air Flow Control Valve in a Vertical Takeoff and Landing Aircraft Thrust Vectoring System written by and published by . This book was released on 1989 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Noise Generated by a Flight Weight Air Flow Control Valve in a Vertical Takeoff and Landing Aircraft Thrust Vectoring System written by Ronald G. Huff and published by . This book was released on 1989 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1989 with total page 960 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA SP written by and published by . This book was released on 1990 with total page 700 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 1989 with total page 140 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 Evaluation of Noise Problems Anticipated with Future VTOL Aircraft written by John N. Cole and published by . This book was released on 1967 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: The potential noise problems anticipated with future VTOL aircraft are analyzed and discussed in general terms, and a brief review of the basic principles of noise generation of various types of propulsion systems proposed for VTOL is included. Primary consideration is given to the noise environments produced in areas adjacent to VTOL sites, since they could cause the most serious noise problem limiting the usefulness of VTOL aircraft. Contours of perceived noise levels are compared for different takeoff and landing profiles of 3-4 passenger, 60 passenger, and 25 ton-lift-crane VTOL aircraft. Criteria and methods for assessing the response of communities to noise from V-port operations are discussed along with the problem of detection of military VTOL aircraft by means of noise. Recommendations are given on the requirements for future research on these noise problems with emphasis on the need for considering noise as an integral part of the design, selection, and test of VTOL aircraft.
Download or read book Cities and Their Vital Systems written by Advisory Committee on Technology and Society and published by National Academies Press. This book was released on 1989 with total page 1298 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cities and Their Vital Systems asks basic questions about the longevity, utility, and nature of urban infrastructures; analyzes how they grow, interact, and change; and asks how, when, and at what cost they should be replaced. Among the topics discussed are problems arising from increasing air travel and airport congestion; the adequacy of water supplies and waste treatment; the impact of new technologies on construction; urban real estate values; and the field of "telematics," the combination of computers and telecommunications that makes money machines and national newspapers possible.
Download or read book Government Reports Annual Index written by and published by . This book was released on 1989 with total page 1708 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1970 with total page 1064 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aircraft Ground Tests and Subscale Model Results of Axial Thrust Loss Caused by Thrust Vectoring Using Turning Vanes written by Steven A. Johnson and published by . This book was released on 1992 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1989-08 with total page 678 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Noise from Gas Turbine Aircraft Engines written by National Industrial Pollution Control Council. Airlines and Aircraft Sub-Council and published by . This book was released on 1971 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation of Flow Instabilities in the Inlet Ducts of Dp 1c Vtol Aircraft written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-05-20 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation of flow instabilities in the inlet ducts of a two-engine vertical takeoff and landing aircraft DP-1C is described in this report. Recent tests revealed that the engines stall during run ups while the aircraft is operating on the ground. These pop stalls occurred at relatively low power levels, sometimes as low as 60 percent of the engine full speed. Inability to run the engines up to the full speed level is attributed to in-ground effects associated with hot gas ingestion. Such pop stalls were never experienced when the aircraft was tested on a elevated grid platform, which ensured that the aircraft was operating in out-of-the-ground-effect conditions. Based on available information on problems experienced with other vertical takeoff and landing aircraft designs, it was assumed that the engine stalls were caused by partial ingestion of hot gases streaming forward from the main exit nozzle under the aircraft inlets, which are very close to the ground. It was also suggested that the nose wheel undercarriage, located between the inlets, may generate vortices or an unstable wake causing intense mixing of hot exit gases with incoming inlet flow, which would enhance the hot gas ingestion. After running a short three-day series of tests with fully instrumented engine inlets, it is now believed the most probable reason for engine pop stalls are random ingestions of a vortex generated between the two streams moving in opposite directions: outbound hot gas stream from the main nozzle close to the ground and inbound inlet flow above. Originally, the vortex is in a horizontal plane. However, at a certain velocity ratio of these two streams, the vortex attaches either to the ground or the aircraft surface at one end and the other end is swallowed by one of the aircraft inlets. Once the vortex enters the inlet duct, a puff of hot air can be sucked through the vortex core into the engine, which causes a serious inlet flow field distortion followed by an engine stall. Once the engine stalls, the outflow from the inlet pushes the vortex away and the engine resumes normal operation. This hypothesis needs to be verified experimentally; e.g., by extensive smoke flow visualization ahead of the aircraft inlets. Lepicovsky, Jan Glenn Research Center FLOW VISUALIZATION; ENGINE TESTS; FLOW STABILITY; ENGINE INLETS; VERTICAL LANDING; DUCTS; VERTICAL TAKEOFF AIRCRAFT; PROPULSION SYSTEM PERFORMANCE; NOSE WHEELS; INLET FLOW; INGESTION (ENGINES); UNDERCARRIAGES
Download or read book Noise Measurements of Model Jet augmented Lift Systems written by Frederick W. Gibson and published by . This book was released on 1972 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Noise measurements were obtained on models of jet-augmented lift systems which are currently being considered for use on proposed short takeoff and landing vehicles. These configurations included a conventional internally blown flap, an augmenter wing, an externally blown flap, and modifications of these basic concepts. The tests were conducted in the Langley anechoic noise facility at zero forward speed with cold air jets. The conventional internally blown flap exhibited lower noise levels than the augmenter wing and the externally blown flap at the same pressure ratios, being of the order of 8 dB or more at the lowest pressure ratio and of the order of 20 dB at the highest pressure ratio of the tests. The data also indicated that for the conventional internally blown flap, there may be an optimum gap size (other than zero) between the turning lip and the flap leading edge from the standpoint of minimum noise generation or admittance. Increasing the trailing-edge thickness of the plain internally blown flap produced no appreciable change in the overall sound pressure level or frequency spectral content in the range of the tests. The data indicated that at a position on the ground directly under the jet exit, the externally blown flap and the augmeter-wing overall noise levels are comparable to each other throughout the pressure range of the tests.
Download or read book Ground and In flight Acoustic and Performance Characteristics of Jet aircraft Exhaust Noise Supressors written by Willard D. Coles and published by . This book was released on 1961 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sound Pressures and Correlations of Noise on the Fuselage of a Jet Aircraft in Flight written by Russell D. Shattuck and published by . This book was released on 1961 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
