Download or read book Finite element Modeling of Parachute Deployment and Inflation written by Wayne D. Sundberg and published by . This book was released on with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: A finite-element method has been developed which provides a detailed dynamic model for all points on a conventional parachute during its deployment and inflation. Both canopy and suspension lines are modeled as two-dimensional, flexible, distributed-mass structures. The canopy is assumed to be axisymmetric, and the effect of this assumption is discussed. The change in canopy porosity with material stretch is considered. Aerodynamic forces are included on the suspension lines. Dynamic modeling for a lines-first deployment begins at a time when both canopy and suspension lines are stowed in an accordion-folded fashion in the deployment bag. The modeling includes line deployment, canopy unfurling, canopy inflation, and disreefing. Emphasis has been placed on the types of physical forces included, and the capability and generality allowed by the model. Some simple wave motion comparisons are included. A sample of the required data for parachute deployment modeling is given. Solutions obtained with the model show the tension wave motion which occurs during deployment and early inflation.

Download or read book New Structural Model for Parachute Inflation Simulations written by and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this project has been to develop a new robust structural model that is being coupled with existing computational fluid dynamics (CFD) codes to accurately simulate the dynamics of parachute and parafoil systems. This research will allow the Army to reduce the time and cost of developing new airdrop systems and retrofitting existing systems for new applications. Parachute dynamics is an extremely complex process. This process is governed by nonlinear time dependent coupling between the parachute and surrounding airflow and involves large canopy shape changes and unconstrained motion of the parachute in the fluid medium. To successfully simulate this complex process, a robust structural model is essential. The following capabilities were added to the structural model: (1) membrane wrinkling, (2) material orthotropy, (3) local bending and damping elements, (4) user defined time dependent element properties, (5) various nonlinear transient solution algorithms, (6) approximate fluid forces, (7) stress projection algorithms, and (8) local nodal coordinate systems. It has been demonstrated that large scale finite element modeling of parachute dynamics is feasible using this structural model. Significant transfer of this basic research was accomplished. New structural model features have continuously been incorporated into a finite element code which has been used extensively by Army engineers to perform simulations of Army parachute systems.

Download or read book Observations on Parachute Scale Factors for Modeling Parachute Deployment and Steady State Performance written by William P. Ludtke and published by . This book was released on 1979 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: A New approach to the scaling of parachute performance is presented, based upon variables inherent in the inflation process such as weight, time, geometry, etc. Limitations of conventional scaling parameters such as Reynold's, Froude, and Mach numbers as applied to parachutes are discussed. Examples of parachute inflation and steady state performance are correlated with a scale factor designated as a Mass Ratio, which is the ratio of the system mass to a mass of atmosphere associated with the parachute size, inflation time, altitude and deployment velocity. For advanced opening shock analyses, the concept of variable mass ratio during canopy inflation is proposed, and the effects of partial canopy inflation at suspension line stretch are discussed. Although the solid cloth types of parachutes are primarily used as examples, the ideas of mass ratio, initial area, and analysis techniques are applicable to all types of parachutes. (Author).

Download or read book Deployment Simulation Methods for Ultra Lightweight Inflatable Structures written by John T. Wang and published by . This book was released on 2003 with total page 28 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 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration and published by . This book was released on with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Enhanced Membrane Elements for Simulation of Parachute Dynamics written by Kun Lu and published by . This book was released on 1999 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis of Deployment and Inflation of Large Ribbon Parachutes written by D. F. McVey and published by . This book was released on 1973 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method for predicting deployment and inflation of reefed ribbon parachutes is presented. The method is based on integration of axial and radial momentum equations developed in the paper. Axial and radial forces are assumed to be describable by drag and radial force coefficients. Computer solutions of the equations are compared to measured parachute loads and to parachute mouth and maximum diameters from tests of 23- and 76-ft diameter conical ribbon parachutes. Comparison of load histories indicated that snatch loads depend to a large extent on deployment bag design and packing influences. Computed loads and parachute size histories for the inflation process compared favorably with flight data. The concept of a radial force coefficient appears to have considerable merit as a means of computing inflation for most parachutes.

Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration. Technical Information Center and published by . This book was released on 1976 with total page 788 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Recovery System Design Guide written by E. G. Ewing and published by . This book was released on 1979 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: This document serves as the third revision of the USAF Parachute Handbook which was first published in 1951. The data and information represent the current state of the art relative to recovery system design and development. The initial chapters describe representative recovery applications, components, subsystems, material, manufacture and testing. The final chapters provide empirical data and analytical methods useful for predicting performance and presenting a definitive design of selected components into a reliable recovery system.

Download or read book Astronautics Aeronautics written by and published by . This book was released on 1979 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1988 with total page 1224 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ERDA Research Abstracts written by United States. Energy Research and Development Administration and published by . This book was released on 1976 with total page 780 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Postflight Simulation of Parachute Deployment Dynamics of Viking Qualification Flight Tests written by Charles H. Whitlock and published by . This book was released on 1973 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Introductory Guide to EC Competition Law and Practice written by Valentine Korah and published by . This book was released on 1994 with total page 2354 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Airdrop Recovery Systems With Self Inflating Airbag written by Hongyan Wang and published by John Wiley & Sons. This book was released on 2017-06-13 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt: A complete reference text to airdrop recovery systems with self-inflating airbags, focusing on analysis, test data, and engineering practicalities Comprehensively covers the fundamental theories, design, matching, and analysis of airdrop recovery systems that include a parachute and self-inflating airbag system Gives step-by-step guidance to aid readers in analyzing and designing their own recovery systems Highlights advanced research programs in the field of airdrop recovery systems, such as simulation and optimization methods.

Download or read book AIAA 83 0313 AIAA 83 0407 written by and published by . This book was released on 1983 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt: