Download or read book Visualization of the Flow Field about Parachute Canopy Models and Approximation of Canopy Pressure Distributions written by Charles A. Babish (III.) and published by . This book was released on 1965 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental investigation of the flow field about rigid two-dimensional models of parachute canopies was conducted. Models representing the inflated profile shapes of the drag-producing surface of nine parachute canopy types were tested in the Air Force Institute of Technology (AFIT) Smoke Tunnel Test Facility. Angles of attack varied from 0 to 30 degrees and photographs of the models and attendant smoke stream patterns were obtained for each test condition.
Download or read book Technical Abstract Bulletin written by and published by . This book was released on with total page 780 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Investigation of the Flow Field During the Inflation of Clustered Parachutes written by R. J. Niccum and published by . This book was released on 1966 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Clustered parachutes during the period of inflation were simulated by elliptical cylinders in potential flow and so-called O'Hara shape parachutes in water flow and wind tunnel experiments. The results are presented in the form of streamline and pressure distribution plots around the respective bodies. Results show that when geometric symmetry is disturbed, the flow field becomes unsymmetrical and strong attractive or repulsive forces are developed. This allows a variety of inflation modes to occur and, hence, poor cluster opening performance.
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 A Method for Calculating the Steady Pressure Field about a Ribbon Parachute Canopy written by Kenneth Kenichiro Muramoto and published by . This book was released on 1982 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analytical method for calculating the steady pressure field about a ribbon parachute canopy is presented. The problem may be formulated as a nonlinear integral equation by treating the canopy as a finite-sized porous screen placed in a channel with an approaching two-dimensional uniform flow. This integral equation is replaced by an auxiliary equation, which is solved by a method of successive substitutions. From the numerical solutions of the integral equation, the differential pressure distribution acting on a 25% geometric porosity ribbon parachute is calculated for various values of channel blockage. These theoretical results are shown to be favorable agreement with experimental data taken from wind tunnel tests.
Download or read book The Effects of Design Parameters and Local Flow Fields on the Performance of Hyperflo Supersonic Parachutes and High Dynamic Pressure Parachute Concepts written by Leland W. Sims and published by . This book was released on 1965 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wake flow field surveys were conducted in the wind tunnel behind several side strut mounted forebodies in the Mach number range from 2 to 5. Studies of the effects of design parameters on Hyperflo supersonic parachutes, and of high dynamic pressure parachute configurations deployed in such wakes were performed. Wake pressure distributions indicated an asymmetry due to the forebody support structure, and a disturbance to the flow field which emanates from the support structure. The latter was most pronounced at Mach numbers above 3. Modification to the wake caused by an air bleed into the forebody base was also indicated. Normal, but higher than predicted axial wake Mach number distributions were found to exist in the forebody wakes. Hyperflo tests at Mach numbers 5 to 5.5 showed abnormally large parachute oscillations with models located at large downstream positions aft of the forebodies. The effects of Hyperflo design parameters and forebody type on model performance are only qualitatively indicated by the tests conducted. (Author).
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 Experimental Determination of Transonic and Supersonic Pressure Distribution and Mass Flow Accommodation for Ribbon Parachutes During Inflation Volume Ii the 17 Geometric Porosity Hemisflo Ribbon Parachute and Circular Flat Ribbon Parachutes with Various Geometric Porosities written by Ronald J. Niccum and published by . This book was released on 1967 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results are presented in this report of an experimental study to determine the air flow through several fully open circular flat ribbon canopies of various geometric porosities and a 17% geometric porosity Hemisflo canopy during its inflation. The measured mass flows are correlated with inviscid flow as a measure of the canopy's accommodation of the air mass available at the mouth inlet under specific operation conditions. In conjunction with the actual measurements of mass flow, the pressure distributions on the internal and external canopy surfaces were determined. These measurements were made on models with suspension lines as well as on models without suspension lines so that suitable estimates of suspension line effects could be made. Measurements were made at Mach 0.8, 1.2, and 3.0. In addition, several tests were conducted in the wake of an ogive cylinder located at two upstream positions. (Author).
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 Experimental Determination of Transonic and Supersonic Pressure Distribution and Mass Flow Accommodation for Ribbon Parachutes During Inflation Vol I the 27 Geometric Porosity Hemisflo Ribbon Parachute written by Ronald J. Niccum and published by . This book was released on 1965 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 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. The wake of the ogive forebody with respect to pressure is analyzed. (Author).
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).
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 Flow Visualization and Mean Pressure and Velocity Measurements Behind the Grid Models written by Hyun-Jin Kim and published by . This book was released on 1986 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flow field past a row of closely spaced flat plates simulating the segment of the ribbon parachute was investigated experimentally both in air and water. Flow visualizations and surface pressure measurements were conducted to study the effect of the spacing ratio and the Reynolds number. Irregular and unstable flow patterns at high solidity configurations were documented in detail. Sensitivity of the flow pattern to the external disturbance was also studied. In addition, mean and fluctuating velocity profile measurements was [sic] conducted in the wake of a flat grid model. The results of the curved grid model indicated a stabilizing effect of the grid curvature.
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 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 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).
