Download or read book Effort of Spanwise Variation of Turbulence on the Normal Acceleration of Airplanes with Small Span Relative to Turbulence Scale written by and published by . This book was released on 1975 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: A rigid airplane with an unswept wing is analyzed. The results show that the power spectrum, relative to that for a one-dimensional turbulence field, is significantly attenuated at the higher frequencies even for airplanes with arbitrarily small ratios of span to scale of turbulence. This attenuation is described by a simple weighting function of frequency that depends only on aspect ratio. The weighting function, together with the attenuation due to the unsteady flow of gust penetration, allows the determination of the average rate of zero crossings for airplanes having very small spans without recourse to an integral truncation which is often required in calculations based on a one-dimensional turbulence field.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1975 with total page 1024 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Comparison of Effects of Unsteady Lift and Spanwise Averaging in Flight Through Turbulence written by and published by . This book was released on 1977 with total page 24 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 1976 with total page 612 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 Government Reports Annual Index written by and published by . This book was released on 1975 with total page 882 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Effects of High altitude Turbulence Encounters on the XB 70 Airplane written by Ronald J. Wilson and published by . This book was released on 1971 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: A turbulence response investigation was conducted with the XB-70 airplane. No special turbulence penetration techniques, speeds, or other restrictions were specified for the investigation, nor were any flights made solely to obtain turbulence data. During 79 flights, turbulence was encountered, and recorded on a VGH recorder, 6.2 percent of the total flight distance at supersonic speeds above an altitude of 12,192 meters (40,000 feet). Geographical locations are given for selected turbulence encounters. For 22 flights the airplane was instrumented to measure true gust velocities and the structural acceleration response to turbulence. The turbulence intensities measured were very low in comparison with those measured at high altitudes in other investigations. Acceleration response spectra, frequency response transfer functions, and coherence functions were computed from three turbulence encounters at Mach numbers of 0.88, 1. 59, and 2.35. Results are compared with calculated studies. Frequencies from the vertical and lateral structural modes, dominant in the airplane acceleration responses, were compared with the natural frequencies of the human body in the vertical and lateral directions.
Download or read book Effect of Spanwise Variations in Gust Intensity on the Lift Due to Atmospheric Turbulence written by Franklin W. Diederich and published by . This book was released on 1957 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: The averaging effect of the span on the lift is shown to be very similar for the normal and the longitudinal components of turbulence, for the various span loadings and turbulence spectra considered herein, and for various angles of sweepback.
Download or read book Government reports annual index written by and published by . This book was released on 199? with total page 896 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Calculated Responses of a Large Sweptwing Airplane to Continuous Turbulence with Flight test Comparisons written by Floyd V. Bennett and published by . This book was released on 1960 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summary: Calculated responses of symmetrical airplane motions, wing deformations, and wing loads due to continuous turbulence are shown to compare favorably with available flight-test results. These calculated responses are based on random-process theory, five degrees of freedom, lifting-surface aerodynamics, and one-dimensional turbulence. Of the five degrees of freedom used only three, rigid-body translation and pitch modes and the first wing bending mode, are shown to contirbute significantly to the airplane responses over the frequency range considered (0 to 2 cps). Bending-moment amplification factors are presented in order to show the effects of dynamic aeroelasticity. These effects are found to increase the response by 35 to 115 percent, depending upon the spanwise station.
Download or read book Fundamental Problematic Issues in Turbulence written by Albert Gyr and published by Birkhäuser. This book was released on 2012-12-06 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: A collection of contributions on a variety of mathematical, physical and engineering subjects related to turbulence. Topics include mathematical issues, control and related problems, observational aspects, two- and quasi-two-dimensional flows, basic aspects of turbulence modeling, statistical issues and passive scalars.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1975 with total page 1032 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulence written by Peter F. Lester and published by Jeppesen Sanderson. This book was released on 1994 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulence, by Peter F. Lester, is the most comprehensive, understandable book available on turbulence as it pertains to aviation. It will help you recognize the conditions that cause turbulence, so the effects can be avoided or minimized. This book provides answers to questions such as: What is turbulence? What does it look like? How long does it last? What causes it? Where is it found? What are its indicators? What are its typical dimensions and intensities?
Download or read book A Method for Estimating Some Longitudinal and Lateral Rigid body Responses of Airplanes to Continuous Atmospheric Turbulence written by Ellwood L. Peele and published by . This book was released on 1971 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method is presented for estimating some lateral and longitudinal rigid-body responses of airplanes to random atmospheric turbulence. Estimates of center-of-gravity load factors and motion responses can be made simply and easily through the use of parametric charts. Sample calculations are included to illustrate the method.
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1973 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Lateral Response of Airplanes to Random Atmospheric Turbulence written by John Marshall Eggleston and published by . This book was released on 1960 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summary: The report is separated into two parts. In the first part the theoretical basis for calculating the lateral motions of an airplane flying through continuous random atmospheric turbulence is presented. The lateral motions are derived in terms of (1) the transfer functions relating the motion in the various degrees of freedom to the yawing moment, rolling moment, and side force, (2) the statistical forces and moments at the center of gravity due to gust velocities acting on the lifting surfaces of the airplane, and (3) the power spectra of the three orthogonal components of gust velocity acting on the airplane along the flight path. The method takes into account the random variations of gust velocity across the span and along the fuselage. Solutions are given in the form of equations relating the power spectra of the angular motions of the airplane to the power spectra of the gust velocities.
Download or read book Aircraft Wake Turbulence and Its Detection written by John Olsen and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 599 pages. Available in PDF, EPUB and Kindle. Book excerpt: The combination of increasing airport congestion and the ad vent of large transports has caused increased interest in aircraft wake turbulence. A quantitative understanding of the interaction between an aircraft and the vortex wake of a preceding aircraft is necessary for planning future high density air traffic patterns and control systems. The nature of the interaction depends on both the characteristics of the following aircraft and the characteristics of the wake. Some of the questions to be answered are: What deter mines the full characteristics of the vortex wake? What properties of the following aircraft are important? What is the role of pilot response? How are the wake characteristics related to the genera ting aircraft parameters? How does the wake disintegrate and where? Many of these questions were addressed at this first Aircraft Wake Turbulence Symposium sponsored by the Air Force Office of Sci entific Research and The Boeing Company. Workers engaged in aero dynamic research, airport operations, and instrument development came from several count ries to present their results and exchange information. The new results from the meeting provide a current picture of the state of the knowledge on vortex wakes and their interactions with other aircraft. Phenomena previously regarded as mere curiosities have emerged as important tools for understanding or controlling vortex wakes. The new types of instability occurring within the wake may one day be used for promoting early dis integration of the hazardous twin vortex structure.
Download or read book Spanwise Measurements of Vertical Components of Atmospheric Turbulence written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-11-06 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Correlation and spectrum magnitude estimates are computed for vertical gust velocity measurements at the nose and wing tips of a NASA B-57B aircraft for six level flight, low speed and low altitude runs and are compared with those of the von Karman atmospheric turbulence model extended for spanwise relationships. The distance between the wing tips was 62.6 ft. Airspeeds ranged from about 330 to 400 ft/sec, heights above the ground ranged from near ground level to about 5250 ft. and gust velocity standard deviations ranged from 4.10 to 8.86 ft/sec. Integral scale lengths, determined by matching measured autocorrelation estimates with those of the model, ranged from 410 to 2050 ft. Digital signals derived from piezoelectric sensors provided continuous pressure and airspeed measurements. Some directional acceleration sensitivity of the sensors was eliminated by sensor orientation, and their performance was spectrally verified for the higher frequencies with supplemental onboard piezoresistive sensors. The model appeared to satisfactorily predict the trends of the measured cross-correlations and cross-spectrum magnitudes, particularly between the nose and wing tips. However, the measured magnitude estimates of the cross-spectra between the wing tips exceeded the predicted levels at the higher frequencies. Causes for the additional power across the wing tips were investigated. Vertical gust velocity components evaluated along and lateral to the flight path implied that the frozen-turbulence-field assumption is a suitable approximation. Sleeper, Robert K. Langley Research Center...
