Download or read book Parachute Stress Analysis Incorporating a Measured Pressure Distribution written by David Paul Saari and published by . This book was released on 1973 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of Parachute Forces and Canopy Pressure Distribution Measured in a Subsonic Wind Tunnel Under Infinite Mass Conditions written by Helmut G. Heinrich and published by . This book was released on 1972 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: For the purpose of parachute canopy stress analysis during the period of inflation, the pressure distribution measured on a ring-slot parachute model is related to the instantaneous parachute force. The correlation of pressure and force data is based on test results established at the Deutsche Forschungsanstalt fuer Luft-und Raumfahrt (DFLR), Braunschweig, Germany. The final pressure-force-time relationship incorporate individual as well as averaged test data. A fair agreement could be shown between measured forces and those obtained from numerical integration of differential pressure over the canopy surface.
Download or read book Parachute Stress Analysis During Inflation and at Steady State written by H. G. Heinrich and published by . This book was released on 1969 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the period from 1965 to 1969, two new methods for stress calculations have been proposed and general remarks primarily concerning the elasticity characteristics of a parachute cloth and pressure distribution have been made. The conservative way of performing a parachute stress snalysis consists of first establishing the geometry of the parachute canopy and then applying a certain pressure distribution. Subsequently, the pressure distribution has been linked to the instantaneous parachute force which can be obtained from an opening shock calculation. In this manner one can possibly obtain closed solutions with a minimum of empirical factors. An example of this approach is presented in detail in the following chapters.
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 The Change of Pressure Distribution on Parachute Canopies During Inflation written by H.-D. Mlzig and published by . This book was released on 1965 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: For a design engineer strength calculation is a prerequisite for completion of design. The parachute designer however encounters great difficulty. Theory provides no means for calculation and almost no data is available of measurements under dynamic conditions to permit adequate strength calculation. The rapidly changing dynamic forces can vastly exceed the steady state forces. Great efforts have been made to predict stresses in a parachute canopy. The latest work for a parachute stress analysis was conducted by H.G. Heinrich and L.R. Jamison [1] and is a great advance. Contrary to former attempts it includes parachute shapes during inflation of the canopy. The great disadvantage of all theoretical attempts is that the actual stress distribution in a canopy is still unknown. No method has yet been found to measure stresses directly in many parts of a canopy.
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 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 Masters Theses in the Pure and Applied Sciences written by Wade H. Shafer and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by TPRC at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemina tion phases of the activity was transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we have concluded that it will be in the interest of all concerned if the printing and distribution of the volume were handled by a well-known publishing house to assure improved service and better communication. Hence, effective with this Volume 18, Masters Theses in the Pure and Applied Sciences will be disseminated on a worldwide basis by Plenum Publishing Corporation of New York. All back issues can also be ordered from Plenum. As we embark on this new partnership with Plenum, we also initiate a new venture in that this important annual reference work now covers Canadian universities as well as those in the United States. We are sure that this broader base will greatly enhance the value of these volumes.
Download or read book Pressure Distribution During Parachute Opening written by H. D. Melzig and published by . This book was released on 1969 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental investigation was conducted to determine the differential pressure distribution over the surface of parachute canopies during the period of inflation under mass conditions. Full scale parachute canopies of the circular flat, 10% extended skirt, ringslot and ribbon types were utilized during the free-flight test program, and differential pressures on the gore centerline and on the cord line were measured by means of four pressure transducers distributed over the canopy in equal distances from the skirt to the vent. In order to analyze the relationships and dependencies between the pressure distribution, projected canopy area, canopy shape, generated force, and dynamic pressure, graphical displays of these quantities were made as a function of time for each type of parachute canopy. The results of the pressure distribution measurements permit a better understanding of the physical nature of the dynamic process of parachute inflation. The stress distribution in a parachute canopy can be calculated if the corresponding canopy shape is known. For this purpose, the evolvement of the canopy shape with the corresponding time is presented for each of the canopy types. (Author).
Download or read book Pressure Distribution in Transonic Flow of Ribbon and Guide Surface Parachute Models written by Helmut G. Heinrich and published by . This book was released on 1958 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes measurements of pressure distributions over the canopy of two rigid parachute models. This study was originated under Contract No. AF 33(616)-3755, but was discontinued through an executive order on Sept. 6, 1957. Because of related studies pursued by Sandia Corporation, Albuquerque, New Mexico, the evaluation and analysis of already recorded data was requested and sponsored by Sandia Corporation through a purchase request issued on March 3, 1958. The investigation was conducted on a guide surface and a ribbon parachute model with 20% geometric porosity. Both models had a 2.5 inch maximum projected diameter. The tests were made in a speed range of M[infinity] = 0.6 to 1.2.
Download or read book Parametric Study of Parachute Pressure Distribution by Wind Tunnel Testing written by William B. Pepper and published by . This book was released on 1975 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pressure distribution data for solid and ribbon parachutes are presented. Three-foot diameter model parachutes of 0, 10, 15, 20, 25, 30, and 40 percent geometric porosity were tested. Suspension line lengths of 1.0, 1.5, and 2.0 constructed diameters were used. Reefing line lengths of 19, 38, and 57-in. were tested. Two 7 x 10-ft, wind tunnels were used to test over a range of dynamic pressure from 35 to 600 lb/ft2. Integration of the measured pressures over the inflated canopy profiles generally resulted in drag force values which agree within 10 percent of force balance drag data.
Download or read book A Theoretical View on the Stress Analysis of Fully Inflated Parachute Canopies written by William P. Ludtke and published by . This book was released on 1984 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes a theoretical approach to the analysis of the force distribution in fully inflated parachute canopies based upon the inflated gore mainseam shape. Normal and tangential forces for any arbitrary point along the gore mainseam can be determined and the magnitude and location of the maximum normal force and cloth stress evaluated. Methods, criteria, and rationale for calculating the force distributions are presented. Originator-supplied keywords include: Canopy shape, and Pressure distribution.
Download or read book Studies of Aerodynamics Dynamics and Stress Analysis of Ribbon Parachutes written by Sandia Corporation and published by . This book was released on 1976 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: The following report describes the continuation of wind tunnel data evaluation as shown in Progress Reports 3 through 14 under Sandia Coropration Contract 63-2241 amd 02-4022, Ref 1 to 13. The data presented in this report are related to disreefing tests of a conical ribbon parachute with 140° included angle, concentric rings, and 25% geometric porosity. The data concerning the canopy profile and pressure distributions will be presented in chronological order starting at the time of disreefing and proceeding through inflation at various time intervals until steady state conditions for the fully inflated parachute are reached. The recorded and derived data recorded and derived data are used to obtain-force time histories which can be compared with a measured force-time recording. Also, so called radial force coefficients are derived which are based on the established canopy profiles and the related pressure data.
Download or read book Pressure Distribution Measurements of Conventional Ribbon Parachutes in Supersonic Flow written by Eugene L. Haak and published by . This book was released on 1962 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Conventionally shaped Ribbon parachutes do not function satisfactorily as aerodynamic decelerators in supersonic flow. Particularly objectionable is their unstable behavior. In order to determine the cause of this structural and dynamic instability, a series of pressure distribution measurements were made on ribbon parachutes at Mach numbers of 0.8, 1.2, 3.0, and 4.5. This report presents the results of measurements and attempts to indicate the effect of suspension lines and forebodies on the pressure distribution of the parachute canopy.
Download or read book Pressure and Canopy Profile Data of 20 Conical Ribbon Parachutes During Inflation written by H. G. Heinrich and published by . This book was released on 1977 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Sandia Laboratories, Albuquerque, N.M., established wind tunnel data of 3 ft ribbon parachute models concerning canopy profiles, drag forces and pressure distribution during the period of inflation. The data were analyzed at the University of Minnesota and resulted in presentations of canopy profile coordinates, drag areas and pressure distributions versus time. Pressure integration about the canopy surfaces as given by the established coordinates provided calculated areas which agreed satisfactorily with measured drag areas. Also, radial force coefficients of the various configurations were established. The results of this study are intended to serve as background information for related investigations such as studies concerning parachute dynamics, stress analysis, etc.
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 141 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 10 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 obtained by means of photographic analysis. Pressure coefficients derived for the steady state (fully open canopy) are quite comparable to the results of previous measurements. Peak pressure values during the unsteady period of inflation were found to be up to 5 times as great as steady state values. The relationships between the pressure distribution and time for each of the canopy models deployed at free-stream velocities between 70 and 160 ft/sec. are presented.
Download or read book Pressure and Profile Data of 20 Conical Ribbon Parachutes written by Helumt G. Heinrich and published by . This book was released on 1977 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Sandia Laboratories, Albuquerque, N.M., established wind tunnel data of 3 ft ribbon parachute models concerning canopy profiles, drag forces and pressure distribution. The data were analyzed at the University of Minnesota and resulted in presentations of drag coefficients, projected diameters and drag areas of reefed and unreefed and parachutes versus geometric porosity and suspension line length as well as in tables and graphs of canopy coordinates and related pressure distributions. Presssure integration about the canopy surfaces as given by the established coordinates provided drag forces which agreed satisfactorily with measured forces. Also, radial force coefficients of the various configurations were established. The results of this study are intended to serve as background information for related investigations such as studies concerning parachute dynamics, stress analysis, etc.
