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 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 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 Technical Abstract Bulletin written by and published by . This book was released on with total page 850 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Determination of the Subsonic Mass Flow Through Several Ribbon Type Parachute Canopies During Inflation and at Steady State Conditions written by Kenneth B. Buchanan and published by . This book was released on 1968 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results of studies to determine the mass flow through circular flat ribbon canopies of several geometric porosities at steady flow conditions and during inflation and through 17% and 27% porous Hemisflo canopies during inflation are presented. Pressure distributions which were established as a necessary part of the study are also included. (Author).
Download or read book A Volume of Technical Papers written by and published by . This book was released on 1966 with total page 258 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 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 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 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 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 Flow Characteristics of Rigid Ribbon Parachute Canopies in Supersonic Flow written by H. G. Heinrich and published by . This book was released on 1965 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: An inlet diffuser model was used in freestream and wake flows to establish the relationship between shock wave standoff distance and mass flow through a cavity. The results of these experiments were used to devise a method to calculate shock wave stanoff distances as a function of the mass flow through the cavity. By means of further experiments, it was shown that this method is useful for carrying out similar calculations for porous parachutes in supersonic flow. The interaction between suspension line boundary layers and the bow shock of porous parachute canopies, and its effect upon the pressure distribution and the pressure drag coefficient, has been studied. Pressure drag coefficients depending on the number of suspension lines were established. (Author).
Download or read book Drag and Stability Characteristics of a Variety of Reefed and Unreefed Parachute Configurations at Mach 1 80 with an Empirical Correlation for Supersonic Mach Numbers written by Lana M. Couch and published by . This book was released on 1975 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation was conducted at Mach 1.80 in the Langley 4-foot supersonic pressure tunnel to determine the effects of variation in reefing ratio and geometric porosity on the drag and stability characteristics of four basic canopy types deployed in the wake of a cone-cylinder forebody. The basic designs included cross, hemisflo, disk-gap-band, and extended-skirt canopies; however, modular cross and standard flat canopies and a ballute were also investigated. An empirical correlation was determined which provides a fair estimation of the drag coefficients in transonic and supersonic flow for parachutes of specific geometric porosity and reefing ratio.
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 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 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 Determination of the Mass Flow Through Parachute Canopies in Subsonic and Supersonic Flow written by R. J. Niccum and published by . This book was released on with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The success of any parachute system is measured by its performance during the opening sequence and its performance during steady state operation. Earlier presentations in this course have shown that the parachute opening time and opening force are important dynamic parameters which may be used in determining a parachute's desirability for certain applications. Similarly, the steady state aerodynamics such as tangent force coefficient, normal force coefficient, and moment derivative with respect to angle of attack are among the parameters employed for gaging a parachute's steady state worthiness. The purpose of this presentation is to bring to your attention still another parameter that is useful in the design and evaluation of the performance characteristics of parachute systems, namely, the mass flow through a canopy both during its inflation and its steady descent.
Download or read book Inflation and Performance of Three Parachute Configurations from Supersonic Flight Tests in a Low density Environment written by Charles H. Whitlock and published by . This book was released on 1969 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ten flight tests of modified-ringsail, disk-gap-band, and cross parachute configurations with deployment at Mach numbers and dynamic pressures corresponding to conditions expected during entry into a Martian atmosphere have been completed. Comparison of flight results indicates that theoretical snatch force values were never exceeded when the deployment techniques of these tests were used. Opening loads showed no definite trend with Mach number. Values for filling times compared favorably with generally accepted empirical curves based on 15-percent geometric porosity. Canopy stability was good when Mach numbers were below 1.4 for the modified-ringsail and disk-gap-band configurations.
