Download or read book Theory and Experiment on Parachute Opening Shock and Filling Time written by H. G. Heinrich and published by . This book was released on 1971 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Theory and Experiment on Parachute Opening Shock and Filling Time written by Helmut G. Heinrich and published by . This book was released on 1971 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method of parachute opening force and filling time calculation is presented which is based on the time functions of aerodynamic drag, included air mass, apparent mass, and effective porosity. Using the momentum and continuity equations, an idealized canopy shape development and a linear drag area-time relationship, expressions are obtained for the canopy volume and velocity. The calculated peak forces agree well with at least mean square averages of field test results of 28-ft solid flat parachutes deployed at speeds from 175 to 450 fps at altitudes of 6,000, 13,000, and 21,000 ft and with suspended weights between 200 and 820 lb.

Download or read book A Parachute Opening Shock Theory Based on Non Linear Time Histories of Inflow Velocity and Projected Area written by Helmut G. Heinrich and published by . This book was released on 1974 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: The concept of a parachute opening shock calculation is shown which is based on the simultaneous solution of the equation of motion and the continuity equation with numerical inputs concerning the development of the projected area and the inflow velocity. Several area-time and velocity-time functions were extracted from wind tunnel and field test data and used for calculating a variety of test cases for which force-time recordings were available. When these functions were used to calculate force-time histories for the test cases from which they were extracted, the calculated histories matched closely the measured ones. A unique set of functions was not found; however, one set was established which in many cases provided acceptable predictions of maximum forces and force-time shapes for parachutes of 3 ft to 100 ft diameter and velocities between 50 ft/sec and 300 ft/sec. Another set of functions, closely related to the one covering the wide range, was established which matched the large parachutes particularly well.

Download or read book WADC Technical Report written by United States. Wright Air Development Division and published by . This book was released on 1953 with total page 1278 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study of Parachute Opening written by J. R. Foote and published by . This book was released on 1958 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: A model of the opening parachute is considered which permits extensive mathematical analysis. Included are the effects of nine physical parameters, governing drag, initial speed and diameter, parachute dimensions and load, altitude, cloth permeability, and a choking factor representing a difference between the model geometry and observed parachute geometry. The governing equations are developed to a point permitting calculations of system speed, opening rate, and shock force as functions of time. Numerous calculations were made in which the choking factor was varied to yield experimentally-known forces, the variation of this factor having been guided by means of analysis of motion pictures of parachute openings. Other theory was developed for calculation of the individual effects of all the parameters upon the shock force. The nature of current measured data and an insufficient number of calculations have not permitted a verification of this theory for calculation of the individual effects of all the parameters.

Download or read book Study of Parachute Opening written by J. R. Foote and published by . This book was released on 1958 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: An outgrowth of Study of the Parachute Opening, Phase I was the realization that more information was neeeded about the actual mouth area as compared to the model mouth area used in that study. The experimental determination of this in terms of a k-factor, the correlation of this with the opening shock forces, and the processing of this data was the purpose of this study. For various reasons the study was incomplete. This report indicates what was to be done, what was done, the difficulties that arose, and make some suggestions about overcoming these difficulties. The point of view taken is that a successful conclusion of the study would have been of some importance and the record of this incomplete study might help to eliminate difficulties in a future study of this type.

Download or read book The Aeronautical Journal written by and published by . This book was released on 1983 with total page 428 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 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Notes on a Theoretical Parachute Opening Force Analysis Applied to a General Trajectory written by William P. Ludtke and published by . This book was released on 1988 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: The report presents a method for calculating the inflation reference time and opening shock forces of the solid-cloth family of parachutes when deployed at an arbitrary trajectory angle to the horizontal. The method is extended to other types of parachutes, but it is limited in that the inflation reference times are not calculated as part of the deployment process. Particular inflation times must be provided as input data to the furnished computer program. The variation of opening shock force versus inflation reference time may be surveyed by providing several values or using actual field test data. Examples are used to demonstrate the effects of canopy cloth rate of airflow, altitude, and trajectory deployment angle for constant velocity and constant dynamic pressure altitude profiles. Keywords: Variable deployment angle, Inflation time, Parachute technology, Opening shock, Calculation methods, Altitude effects.

Download or read book Catalog of Copyright Entries Third Series written by Library of Congress. Copyright Office and published by Copyright Office, Library of Congress. This book was released on 1973 with total page 1040 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Collection of Technical Papers written by and published by . This book was released on 1973 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dynamics of the Opening Parachute written by J. R. Foote and published by . This book was released on 1952 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A model of the opening parachute is proposed and the equations of continuity and of motion are written. The two main parameters are: a coefficient to account for cloth porosity, and a coefficient to provide some choking of the mouth due to looseness of the cloth. The equations are solved under certain assumptions and the results are used to predict both how the force on the suspended load and how the opening rate vary with time. Experimental data is used to select values of the porosity coefficient for various altitudes. In each case the predicted shock force maximum is of the proper order of magnitude, as shown by experiment. A drag term is used which is the sum of the usual type of viscous drag term and a set of inertial drag terms calculated by F.S. Weinig for an expanding sphere. The viscous drag term is of leading importance. The drag coefficient is varied with the porosity coefficient by means of a type of formula indicated by experiment. This gives a greater drag coefficient at higher altitudes and helps to cause a greater shock force at higher altitudes and helps to cause a greater shock force by giving a greater opening rate and less parachute filling time.

Download or read book A Linearised Theory of Parachute Opening Dynamics written by Helmut G. Heinrich and published by . This book was released on 1972 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The inflation of a parachute encompasses problems of aerodynamics, dynamics, and elasticity. The most noticeable effects of the interaction of the events are the opening force and the filling time. Attempts to analyse the opening process and to predict the opening force date back to 1927. Since then a considerable number of methods have been published. Some of them are primarily analytical, others more empirical, and several deal with isolated problems. The earliest and most analytically oriented studies are by Scheubel and O'Hara.

Download or read book Aerodynamic Decelerators a Course Syllabus written by Michael Ravnitzky and published by . This book was released on 1984 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Calculation of Filling Time and Transient Loads for a Parachute Canopy During Deployment and Opening written by Bruce Wilcox and published by . This book was released on 1958 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: Theoretical relations are developed for use in predicting the filling time and transient shock forces during the deployment and opening of a parachute canopy. These relations are used to calculate filling times and loads which are compared with measured values obtained from fullscale parachute research flight tests. The comparison is shown to be good.

Download or read book Aeronautical Engineering written by and published by . This book was released on 1971 with total page 580 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 Performance of and Design Criteria for Deployable Aerodynamic Decelerators written by George Chernowitz and published by . This book was released on 1964 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present state-of-the-art, technology, and theory applicable to deployable aerodynamic decelerators, especially textile parachute canopies, are presented. Major types of decelerators are described, and their aerodynamic and operational characteristics, as well as applications, are discussed. Detailed coverage is given to decelerator materials, design and construction, hardware, test methods and vehicles, and test instrumentation. Decelerator design procedures and performance prediction techniques are demonstrated by sample calculations.