Download or read book Drag and Stability of Guide Surface Ribbon and Ringslot Parachutes at High Subsonic Speeds written by E. L. Haak and published by . This book was released on 1965 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: Four conventional type parachutes; namely, a ribbed and a ribless guide surface parachute and a ribbon and ringslot parachute were tested at Mach numbers of 0.5 and 0.8 to establish their drag and stability characteristics and to evaluate their general performance in this Mach number range. In all cases the parachute models were stable and their drag coefficient increased slightly with increasing Mach number. It was found that both the drag and the stability of the guide surface type parachutes change with cloth porosity. Tests also indicate that for both the ribbed and ribless guide surface parachutes, the tangent force coefficient increases with increasing stagnation pressure at a constant Mach number, and while the stability of the ribless guide surface parachute increases, that of the ribbed type is essentially unchanged. (Author).

Download or read book Wind tunnel Investigation of Drag and Stabili Ty of Parachutes at Supersonic Speeds written by Nickolai Charczenko and published by . This book was released on 1964 with total page 30 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 Technical Abstract Bulletin written by and published by . This book was released on with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Symposium on Parachute Textiles written by Joyce C. McGrath and published by . This book was released on 1954 with total page 222 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 1978 with total page 504 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.

Download or read book Low speed Free flight Stability and Drag Characteristics of Radially Vented Parachutes written by Sanger M. Burk and published by . This book was released on 1964 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: A drop-test investigation has been conducted to determine the stability and drag characteristics of radially vented (duplex) parachutes. Parachutes of two different designs were tested: a large parachute with high geometric porosity and a small parachute with low geometric porosity designed for the same descent velocity with the same load. The results of the tests show that the large high-porosity duplex parachute was very stable in descent, oscillations averaging about [plus-or-minus]3.40; and the average drag coefficient based on the total canopy area and based on the fabric area alone were approximately 0.38 and 0.55, respectively. The small, low-porosity duplex parachute was also very stable in descent, oscillations averaging about [plus-or-minus]4.50; and the average drag coefficients based on the total canopy area and based on the fabric area alone were approximately 0.62 and 0.79, respectively. The oscillations for the cluster of three solid flat circular parachutes, tested for comparison purposes, were [plus-or-minus]7.10. The average drag coefficients based on the total canopy area and the fabric area alone were approximately 0.64 and 0.65, respectively.

Download or read book Parachute Recovery Systems written by Theo W. Knacke and published by . This book was released on 1992 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this manual is to provide recovery system engineers in government and industry with tools to evaluate, analyze, select, and design parachute recovery systems. These systems range from simple, one-parachute assemblies to multiple-parachute systems, and may include equipment for impact attenuation, flotation, location, retrieval, and disposition. All system aspects are discussed, including the need for parachute recovery, the selection of the most suitable recovery system concept, concept analysis, parachute performance, force and stress analysis, material selection, parachute assembly and component design, and manufacturing. Experienced recovery system engineers will find this publication useful as a technical reference book; recent college graduates will find it useful as a textbook for learning about parachutes and parachute recovery systems; and technicians with extensive practical experience will find it useful as an engineering textbook that includes a chapter on parachute- related aerodynamics. In this manual, emphasis is placed on aiding government employees in evaluating and supervising the design and application of parachute systems. The parachute recovery system uses aerodynamic drag to decelerate people and equipment moving in air from a higher velocity to a lower velocity and to a safe landing. This lower velocity is known as rate of descent, landing velocity, or impact velocity, and is determined by the following requirements: (1) landing personnel uninjured and ready for action, (2) landing equipment and air vehicles undamaged and ready for use or refurbishment, and (3) impacting ordnance at a preselected angle and velocity.

Download or read book Investigation of the Characteristics of 6 foot Drogue stabilization Ribbon Parachutes at High Altitudes and Low Supersonic Speeds written by Clinton T. Johnson and published by . This book was released on 1960 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: Performance data are presented for two types of ribbon parachutes. The parachutes were forcibly deployed from an air-launched test vehicle at altitudes from 55,000 feet to 70,000 feet and at Mach numbers between 0.92 and 1.52. Opening shock, steady-state drag performance, and canopy-porosity effects are evaluated with respect to Mach number and dynamic pressure. The conical canopy design appears to function far better than the flat canopy at supersonic deployment speeds. The relatively high-porosity conical design improves the parachute stability, with the added benefit of a low opening shock. The drag efficiency of the conical canopy is equivalent to that of the flat canopy having 50-percent-lower porosity. Riser elasticity and length also appear to be important parameters affecting the parachute stability. Reducing the weight of the test vehicle by a factor of one-third had a negligible effect on the stability and drag characteristics of the parachute.

Download or read book Aerodynamic Investigation of Submunition Stabiliation Retardation and Dispersion Concepts written by James E. Brunk and published by . This book was released on 1974 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Model Parachutes Comparison Tests of Various Types written by T. W. Knacke and published by . This book was released on 1949 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind tunnel and drop tests were made on model parachutes of various types, to study the influence o[n] performance of such factors as design, shape, size, load, porosity, and line length. All the unstable parachutes which were tested, such as solid flat, solid conical, and solid spherical types, have a pronounced increase in the drag coefficient C[subscript]D with decreasing rate of descent in the range of 35 to 8[0 fps]. The stable prarachutes, including the high porosity, pseudo-ribbon, guided surface, and ribbon, have a practically constant C[subscript]D. Square and triangular parachutes have higher drag than round parachutes o[f the] same area. Thirty-degree-conical and quarter-spherical parachutes have higher drag than flat and hemispherical parachutes. The Airfoil parachute has higher drag than the standard flat parachute an[d] is fairly stable. The length of the suspension lines influences the drag.

Download or read book Symposium on Parachute Textiles written by Joyce C. McGrath and published by . This book was released on 1954 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Symposium on Parachute Technology and Evaluation written by Earl C. Myers and published by . This book was released on 1964 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book WInd tunnel Investigation of the Opening Characteristics Drag and Stability of Several Hemispherical Parachutes written by Stanley H. Scher and published by . This book was released on 1949 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation has been conducted to determine the opening characteristics of several hemispherical parachutes and to study the influence of the parachute design variables on these opening characteristics. The effects of design variables on the drag and stability characteristics of the parachutes were also evaluated.

Download or read book Aerodynamic Characteristics of the Supersonic Guide Surface and the Spiked Ribbon Parachutes written by Helmut G. Heinrich and published by . This book was released on 1965 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: The location of shock waves, the pressure distribution and the mass flow, which are significant for the functioning of a parachute in supersonic flow, are discussed and some advantageous conditions are postulated. Wind tunnel studies are described in which the validity of the assumptions has been checked by means of models of a modified guide surface canopy combined with a shock producing cone. A configuration was found according to which 4 inch textile models function satisfactorily up to Mach numbers of 4.5. The results of further supersonic wind tunnel tests are shown in which a 4 ft supersonic guide surface parachute, built in accordance with the established aerodynamic parameters, functioned satisfactorily. This parachute collapsed due to structural weakness at a Mach number of 2.8 after being exposed to supersonic flow for approximately 90 minutes. The concept of the wake producing cone in conjunction with ribbon parachute canopies was also tried, but no satisfactory configuration was found. (Author).

Download or read book Recovery Systems for Missiles and Target Aircraft written by Dr. J. R. Downing and published by . This book was released on 1954 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: The characteristics of Guide Surface, Ribbon and Rotafoil parachutes operated in the speed ranges up to 500 miles per hour are described. These characteristics were determined by means of two tests conducted with rocket powered test vehicles operated on the Free Air Test Facility Track at Edwards Air Force Base. The various parachutes tested are intended for use as parabrakes to decelerated high velocity missiles to relatively low speeds at which large parachutes can be satisfactorily deployed to accomplish safe recovery. All test parachutes were designed to have drag areas of approximtely 28 ft2 and factors of safety of 1.5 at 400 miles per hour. The data obtained during this test program included inflation times, opening shock factors, drag forces and inflated diameters of the test parachutes at various deployment speeds. These data are used to provide design information about drag coefficients, critical opening speeds, porosities, and strength requirements for these parachutes.