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 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 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 Scientific and Technical Aerospace Reports written by and published by . This book was released on 1974 with total page 992 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 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 A Theoretical Analysis of the Aerodynamic and Structural Forces Associated with a Ribbon Parachute Canopy in Steady Descent written by Kenneth Kenichiro Muramoto and published by . This book was released on 1983 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 Parachute Canopy Stress Measurements at Steady State and During Inflation written by H. G. Heinrich and published by . This book was released on 1978 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Circumferential stresses were measured on 5-ft flat circular block-constructed solid cloth and ring slot parachutes in a wind tunnel during inflation under infinite mass condition and at steady state. Five Omega sensors placed along gore centerlines and a force link measured stresses and the parachute force versus time. Radial stresses were measured on a 3-ft solid flat circular block-constructed parachute at steady state. Stress measurements were evaluated in view of maximum and steady-state stresses versus location and time, as well as in respect to the parachute force. The measurements indicated strong stress variations, being different for both types of parachutes. In the 3-ft solid cloth parachute, the radial stress was, at certain locations, greater than the circumferential stress.
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 Aeronautical Engineering written by and published by . This book was released on 1991 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dynamic Pressure Distribution on Parachute Canopies written by H.-D. Melzig and published by . This book was released on 1968 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental investigation was conducted to determine the differential pressure distribution on the canopies of four types of parachutes (Circular Flat, 10 % Extended Skirt, Ringslot, Circular Flat Ribbon) during the period of inflation under finite mass conditions. In flight tests the differential pressure on the cord and the gore center line was measured with four pressure transducers distributed over the canopy in equal distances from the skirt to the vent.
Download or read book Dynamic Pressure Distribution on Parachute Canopoes written by H.-D. Melzig and published by . This book was released on 1967 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The pressure distribution on the canopies of several types of parachutes shall be determined under finite mass conditions. These types are the Circular Flat, the Extended Skirt, the Ring-slot and the Circular Flat Ribbon parachute. The pressure distribution during filling and at steady state shall be related to the instantaneous canopy profile. Furthermore, an attempt shall be made to establish a general relationship between canopy profile and pressure distribution. The snatch velocity shall be held constant at approximately 110 knots, while the canopy loading shall be limited to the range between 0.3 and 0.7 lbs/ft2.
Download or read book Experimental Determination of Transonic and Supersonic Pressure Distribution and Mass Flow Accommodation for the Hemisflo Ribbon Parachute During Inflation written by Ronald J. Niccum and published by . This book was released on 1965 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents the results of an experimental study to qualitatively determine the air flow through a Hemisflo ribbon parachute during the inflation process. These measured mass flows are analyzed relative to free stream velocity and density ratio. The results are presented as ratios of measured to inviscid flow through the canopy inlet area, thus giving a measure of the canopy's ability to accommodate the air mass entering the parachute mouth. Related to the mass flow studies, was the determination of pressure distributions on the internal and external canopy surfaces. Measurements were made at Mach 0.8, 1.2, and 3.0. In addition, several tests were conducted using an ogive forebody at two upstream locations.
Download or read book Force Distribution in the Suspension Lines of Cross Parachutes written by William P. Ludtke and published by . This book was released on 1989 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: The force distribution in the several suspension lines attached to an arm of a Cross-type parachute is nonuniform. The outer suspension lines carry the minimum force. The forces increase in each suspension line as the line attachment approaches the center of the arm with the maximum force carried by the most central lines. This report describes a series of wind tunnel tests to measure the forces in individual selected suspension lines of Cross type parachutes with 8, 16, and 24 suspension lines. The test results show that lengthening the inner suspension lines tends to equalize the suspension line forces. The static pressure distribution adjacent to the parachute center line was measured for each parachute model. Positive pressures were found to exist ahead of the canopy skirt hem as well as inside of the canopy. The magnitude of the pressures is influenced by the canopy cloth permeability.
Download or read book PARACHUTE CANOPIES DURING INFLATION written by H. D. Melzig and published by . This book was released on 1965 with total page 137 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 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 in detail and correlated with changing canopy shape. A complete shape analysis is made and a mathematical model is proposed. (Author).
