Download or read book Equations of Motion of Slung Load Systems Including Multilift Systems written by National Aeronautics and Space Adm Nasa and published by . This book was released on 2018-11-17 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: General simulation equations are derived for the rigid body motion of slung-load systems. This work is motivated by an interest in trajectory control for slung loads carried by two or more helicopters. An approximation of these systems consists of several rigid bodies connected by straight-line cables or links. The suspension can be assumed elastic or inelastic. Equations for the general system are obtained from the Newton-Euler rigid-body equations with the introduction of generalized velocity coordinates. Three forms are obtained: two generalize previous case-specific results for single-helicopter systems with elastic and inelastic suspensions, respectively; and the third is a new formulation for inelastic suspensions. The latter is derived from the elastic suspension equations by choosing the generalized coordinates so that motion induced by cable stretching is separated from motion with invariant cable lengths, and by then nulling the stretching coordinates to get a relation for the suspension forces. The result is computationally more efficient than the conventional formulation, is readily integrated with the elastic suspension formulation, and is easily applied to the complex dual-lift and multilift systems. Results are given for two-helicopter systems; three configurations are included and these can be integrated in a single simulation. Equations are also given for some single-helicopter systems, for comparison with the previous literature, and for a multilift system. Equations for degenerate-body approximations (point masses, rigid rods) are also formulated and results are given for dual-lift and multilift systems. Finally, linearlized equations of motion are given for general slung-load systems are presented along with results for the two-helicopter system with a spreader bar. Cicolani, Luigi S. and Kanning, Gerd Ames Research Center ALGORITHMS; EQUATIONS OF MOTION; HAULING; HELICOPTERS; LOADS (FORCES); RIGID STRUCTURES; SUSPENDING (HANGING); TETHERING; COM...

Download or read book Equations of Motion of Slung load Systems Including Multilift Systems written by Luigi S. Cicolani and published by . This book was released on 1992 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Equations of Motion of Slung Load Systems with Results for Dual Lift written by Luigi S. Cicolani and published by . This book was released on 1990 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Scientific and Technical Aerospace Reports written by and published by . This book was released on 1990 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Monthly Catalogue United States Public Documents written by and published by . This book was released on 1993 with total page 1786 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Monthly Catalog of United States Government Publications written by United States. Superintendent of Documents and published by . This book was released on 1993 with total page 1072 pages. Available in PDF, EPUB and Kindle. Book excerpt: February issue includes Appendix entitled Directory of United States Government periodicals and subscription publications; September issue includes List of depository libraries; June and December issues include semiannual index

Download or read book Development of Handling Qualities Criteria for Rotorcraft with Externally Slung Loads written by and published by . This book was released on 2006 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Equations of Motion of Slung Load Systems with Results for Dual Lift written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-02 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: General simulation equations are derived for the rigid body motion of slung load systems. These systems are viewed as consisting of several rigid bodies connected by straight-line cables or links. The suspension can be assumed to be elastic or inelastic, both cases being of interest in simulation and control studies. Equations for the general system are obtained via D'Alembert's principle and the introduction of generalized velocity coordinates. Three forms are obtained. Two of these generalize previous case-specific results for single helicopter systems with elastic or inelastic suspensions. The third is a new formulation for inelastic suspensions. It is derived from the elastic suspension equations by choosing the generalized coordinates so as to separate motion due to cable stretching from motion with invariant cable lengths. The result is computationally more efficient than the conventional formulation, and is readily integrated with the elastic suspension formulation and readily applied to the complex dual lift and multilift systems. Equations are derived for dual lift systems. Three proposed suspension arrangements can be integrated in a single equation set. The equations are given in terms of the natural vectors and matrices of three-dimensional rigid body mechanics and are tractable for both analysis and programming. Cicolani, Luigi S. and Kanning, Gerd Ames Research Center RTOP 505-66-01...

Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1996 with total page 708 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 2001 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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Download or read book Aeronautical Engineering written by and published by . This book was released on 1990 with total page 184 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 International Aerospace Abstracts written by and published by . This book was released on 1996 with total page 970 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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Download or read book Introduction to Helicopter and Tiltrotor Flight Simulation written by Mark E. Dreier and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presemts the tools required to write a flight simulation mathematical model in one comprehensive reference. Chapters on the aerodynamics and dynamics of fuselages, wings, propellers, rotors, landing gear, engines, drive trains, controls, and aerodynamic interference precede the chapters on organisation, information flow, and trimming methods.