Download or read book Parachute Opening Shock Calculations with Experimentally Established Input Functions written by Helmut G. Heinrich and published by . This book was released on 1975 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: Parachute opening shock calculations with experimentally established area- and velocity-time functions are shown which, in combination with the momentum and continuity equations, yield force-time histories that satisfactorily agree in shape and force level with measured force-time diagrams. Two conjugate functions were found which approach and provide satisfactory force-time histories of solid flat circular parachutes of 3-100 ft diameter, with loads of 0.5-5400 lb at snatch velocities between 50 and 360 fps.
Download or read book Parachute Opening Shock Calculations with Experimentally Established Velocity and Area Functions written by H. G. Heinrich and published by . This book was released on 1975 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 A Method for the Calculation of Parachute Opening Forces for High Altitude Balloon Payloads written by Peter L. Miller and published by . This book was released on 1975 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the questions most frequently asked by scientists/experimenters who design balloon payloads concerns the magnitude of the opening forces of the parachute recovery system. Existing theory and an analytical method recently developed for horizontal deployment are adapted to balloon systems requirements. Engineering methods are used to develop expressions which allow the assessment of the parachute opening forces.
Download or read book An International Survey of Shock and Vibration Technology written by Henry C. Pusey and published by . This book was released on 1979 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1974 with total page 620 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Calculation of Parachute Opening Shock Forces written by Thornton Blanchard and published by . This book was released on 1958 with total page 108 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 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 Numerical Solutions to the Opening Dynamics of a Parachute written by Bruce R. White and published by . This book was released on 1974 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: In view of existing closed solutions of the parachute opening problem, a numerical solutions technique is presented for generating solutions of the maximum opening force vs deployment velocity of a 28-ft solid flat parachute with a suspended weight of 200 lbs. Also calculated are the filling times of the inflation process. Time-dependent functions of the aerodynamic drag, included air mass of the canopy, apparent mass, inflow velocity function, and a non-linear area-time curve, are used with the momentum and continuity equations at altitudes of 6000, 13,000, and 21,000 ft in the numerical solutions. An idealized canopy shape-time development assumption is made in the calculations. The calculated maximum forces agreed well with experimental test data for some of the empirically selected velocity functions for the 13,000- and 21,000-ft altitude test cases. The maximum calculated forces of the 6000-ft altitude was found to be low in comparison with the experimental field tests. The calculated filling times by use of the continuity equation are generally found to be in excess of the measured filling times from the field tests.
Download or read book The Shock and Vibration Digest written by and published by . This book was released on 1973 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Calculation of Parachute Opening Shock written by K. H. Fu and published by . This book was released on 1976 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of the parameters (mass, air density and velocity) on the opening shock factor for the Circular Flat Parachute is investigated. The opening forces are calculated not only according to the method given in the Parachute Handbook of the U.S. Air Force but also by using the opening relations given by R. Berndt.
Download or read book Journal of Hydronautics written by and published by . This book was released on 1978 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Notes on a Parachute Opening Force Analysis Applied to a Vertical Toward the Earth Trajectory written by William P. Ludtke and published by . This book was released on 1987 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recovery of payloads from high altitude often requires the deployment of parachutes on trajectories that are essentially vertical and toward the earth. The parachute opening shock force developed by a parachute deployed in this manner exceeds the opening shock force of the same parachute system deployed horizontally at the same altitude and velocity. As the deployment trajectory angle varies from horizontal to vertical, the opening shock force increased to a maximum. Hence, the vertical trajectory has special significance. This report develops an analysis to permit the calculation of opening shock forces in vertical deployment. The validity of the rule of thumb that 'the vertical deployment opening shock force exceeds the horizontal shock force by one 'g' is tested, and criteria are developed. Examples are used to demonstrate applications of the approach, and a method of calculating the inflation time of Solid Cloth parachutes in vertical fall developed. Keywords: Vertical inflation time; Limiting ballistic mass ratio.
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 Publications of the AIAA written by American Institute of Aeronautics and Astronautics and published by . This book was released on 1968 with total page 542 pages. Available in PDF, EPUB and Kindle. Book excerpt:
