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 Technical Data Digest written by and published by . This book was released on 1950 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 WADC Technical Report written by United States. Wright Air Development Division and published by . This book was released on 1955 with total page 1286 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 Confidential Documents written by United States. Army Air Forces and published by . This book was released on 1950 with total page 958 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 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 Stress Analysis of a Parachute During Inflation and at Steady State written by Helmut G. Heinrich and published by . This book was released on 1965 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: The stresses occurring in the cloth of an opening parachute and at steady state are calculated. The method is based on assumed instantaneous and steady state shapes and related pressure distributions. It is general and may be applied to any type and size of canopy built out of solid cloth. The presented analysis is limited to canopies constructed of triangular gores, but can be extended to other gore patterns. A numerical calculation is made for the Solid Flat, Circular Parachute during the opening and at steady state.

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 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 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 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 Quartermaster Professional Bulletin written by and published by . This book was released on 1995 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Stress Analysis of a Fully Inflated Ribless Guide Surface Parachute written by H. G. Heinrich and published by . This book was released on 1965 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: A stress analysis of a fully inflated ribless guide surface parachute is presented. The method ia an extension of an earlier publication, which is applicable to the transient state of inflation. However, in view of the normal use of ribless guide surface parachutes, the transient phase is considered to be less important since for the so-called infinite mass cases, the maximum force is considered to occur when full inflation is reached. In general, this analysis can be applied to most canopies having non-triangular gore patterns. A numerical calculation is made for a 12-gore ribless guide surface parachute over a range of pressure loadings, canopy sizes, and cloth types representing practical application.

Download or read book The Aeronautical Journal written by and published by . This book was released on 1985 with total page 1004 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 1975 with total page 542 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 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.