Download or read book An Analysis of Parachute Opening Forces written by Harry Erwin Ruhsam and published by . This book was released on 1961 with total page 50 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 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 Notes on a Generic Parachute Opening Force Analysis written by William P. Ludtke and published by . This book was released on 1986 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: The determination of parachute opening shock forces is one of the most vital elements in decelerator system design. This report develops a generic opening shock analysis that permits calculation of velocity profiles, shock factors, maximum shock forces and their time of occurrence during deployment for many types of parachutes. Criteria are presented and methods of calculation developed. Application of the analysis to an apparent anomaly in solid cloth parachute finite mass deployment, verifies the parachute diameter effect shown in the test performance. This is illustrated by an example. (Author).
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 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 Techniques for Selection and Analysis of Parachute Deployment Systems written by Earle K. Huckins and published by . This book was released on 1970 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Notes on a Generic Parachute Opening Force Analysis written by William P. Ludtke and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The determination of parachute opening shock forces is one of the most vital elements in decelerator system design. This report develops a generic opening shock analysis that permits calculation of velocity profiles, shock factors, maximum shock forces and their time of occurrence during deployment for many types of parachutes. Criteria are presented and methods of calculation developed. Application of the analysis to an apparent anomaly in solid cloth parachute finite mass deployment, verifies the parachute diameter effect shown in the test performance. This is illustrated by an example.
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 Notes on the Opening Behaviour and the Opening Forces of Parachutes written by F. O'Hara and published by . This book was released on 1949 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: An approximate theory of parachute opening is suggested. A formula is derived for the critical opening speed (the highest speed at which the canopy develops fully) which indicates variation of the critical speed with fabric porosity, rigging line length and so forth, of the order observed in wind tunnel tests. Assuming a simple form for the air flow about the parachute, a formula is obtained also for the rate of opening of a canopy. This enables an analysis to be made of the motion of a store-parachute system during canopy development. The theory confirms the possiblilty of a large increase with altitude, found experimentally, in the maximum parachute force on the store.
Download or read book Analysis of Parachute Opening Dynamics with Supporting Wind Tunnel Experiements written by Helmut G. Heinrich and published by . This book was released on 1968* with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study is concerned with identification of significant terms in the process of parachute inflation. For finite mass cases, the equations of motion for parachutes inflating in free air and in wind tunnel experiments are established and organized in view of the nonsteady terms of canopy size, systems velocity, included and apparent masses, and the time derivatives of these terms. Wind tunnel experiments are described, the results of which yield graphical and numerical time functions for the significant terms of the equation of motion and the force-time histories. The wind tunnel results are compared with full size test information and certain identities are shown. The significant terms are combined to functions unique for the test conditions and substituted in the equation of motion. Force-time functions so derived compare satisfactorily with measured force histories and the contributions of the individual terms to the instantaneous parachute force can be seen.
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 0 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 Elementary Estimates of Parachute Opening Forces written by M. H. L. Waters (B.Sc.(Eng)) and published by . This book was released on 1957 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: Simple assumptions of the rate of parachute inflation are used to construct data sheets for parachute maximum loads and other quantities. The aim is to present an elementary analysis in detail as a basis for future comparison with experiment. Appendices treat non-horizontal motion of the parachute and store, and estimate the effect on the opening load, of the virtual air mass associated with the canopy. The 'shock factor' as measured in wind tunnel tests is also discussed, and the last Appendix extends the method of calculation to reefed parachutes.
Download or read book Pressure Distribution During Parachute Opening written by H. D. Melzig and published by . This book was released on 1966 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental investigation and correlative analysis were conducted to determine the pressure distribution over the surface of parachute canopies during the period of inflation for the infinite mass case and to correlate pressure coefficients with inflating canopy shapes. Parachute canopy models of Circular Flat, 10% Extended Skirt, Ringslot, and Ribbon designs were tested under infinite mass conditions in a 9 x 12 ft low speed wind tunnel. External and internal pressure values were measured at various locations over the surface of the model canopies throughout the period of inflation, and generalized canopy profile shapes were obtined by means of photographic analysis.
Download or read book Analysis of Parachute Deployment of Heavy Cargo written by Helmut G. Heinrich and published by . This book was released on 1963 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: All available experimental values of extraction time, deployment time, opening time, and effective drag coeficient of standard serial delivery systems have been gathered and reduced to comparable conditions. A study has been made to determine the governing parameters in the delivery sequence, and representative values of these parameters have been determined through statistical analysis where possible.
Download or read book An Analysis of Parachute Opening Shocks written by Charles H. Lowry and published by . This book was released on 1957 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of Parachute Scale Effects written by William B. Walcott and published by . This book was released on 1963 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study was conducted to determine the effects of changing scale upon drag coefficients, filling time, peak opening force, and stability for single, unreefed textile parachute canopies. The investigation was confined to Flat Circular, Extended Skirt, Ringslot, Ribless Guide Surface, Circular Flat Ribbon, and Conical Ribbon parachutes operating in the subsonic flow regime at altitudes below 20,000 feet. As an integral part of the study, a survey of the existing literature and test data, a compilation of all pertinent data, and recommendations for future experimental investigations were made. Scaling equations with associated 95-percent confidence intervals were developed for the drag coefficient of the Flat Circular and Extended Skirt parachutes through the use of multiple regression analysis which the indicates the significant variables and their functional forms. Because the available data was poorly distributed, the equations will have to be used circumspectly to avoid misleading conclusions.
