Download or read book Parachute Performance Simulations written by Richard J. Benney and published by . This book was released on 1998 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance of a 26 meter diameter Ringsail Parachute in a Simulated Martian Environment written by Charles H. Whitlock and published by . This book was released on 1967 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inflation, drag, and stability characteristics of an 85.3-foot (26 meter) nominal diameter ringsail parachute deployed at a Mach number of 1.15 and at an altitude of 132,600 feet (40.42 kilometers) were obtained from the first flight test of the Planetary Entry Parachute Program. After deployment, the parachute inflated to the reefed condition. However, the canopy was unstable and produced low drag in the reefed condition. [remainder of summary illegible].

Download or read book Development of a Total Trajectory Simulation for Parachute load Systems written by H. G. Heinrich and published by . This book was released on 1973 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method of total trajectory simulation was established which is based on the governing equations of the various phases of an aerial delivery or recovery system. In view of these equations, a computer program capable of predicting the performance characteristics of a parachute-load system from the instant of initiation to the moment of landing was established. Calculations were performed for a number of different aerial delivery systems. The calculated results fall well within the broad ranges of expected performance, based upon a familiarity with field test results. The system is ready to be used for overall prediction of parachute performance characteristics and an intensive comparison of calculated and recorded field test results is highly desirable for validation and improvement of the technique of total trajectory simulation.

Download or read book Development of a Total Trajectory Simulation for Single Recovery Parachute Systems written by H. G. Heinrich and published by . This book was released on 1973 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A method of total trajectory simulation was established which is based on the governing equations of the various phases of an airdrop or recovery system. In view of these equations, a computer program capable of predicting the performance characteristics of a parachute-load system from the instant of initiation to the moment of landing was established. Calculations were performed for a number of different aerial delivery systems. The calculated results fall well within the broad ranges of expected performance, based upon a familiarity with field test results. The system is ready to be used for overall prediction of parachute performance characteristics and an intensive comparison of calculated and recorded field test results is highly desirable for validation and improvement of the technique of total trajectory simulation. The report is presented in two volumes.

Download or read book Full scale Simulation of Parachute Deployment Environment in the Atmosphere of Mars written by Clarence L. Gillis and published by . This book was released on 1968 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: A flight-test program was conducted to investigate the operating characteristics of large-size parachutes in an environment simulating that expected during a Mars landing mission. The choice of simulation parameters is discussed and the effects on the results of those quantities not simulated are considered. The environmental factors of major importance to the performance of the parachutes appear to have been adequately represented in the tests.

Download or read book Development of a Massively Parallel Parachute Performance Prediction Code written by and published by . This book was released on 1997 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Department of Energy has given Sandia full responsibility for the complete life cycle (cradle to grave) of all nuclear weapon parachutes. Sandia National Laboratories is initiating development of a complete numerical simulation of parachute performance, beginning with parachute deployment and continuing through inflation and steady state descent. The purpose of the parachute performance code is to predict the performance of stockpile weapon parachutes as these parachutes continue to age well beyond their intended service life. A new massively parallel computer will provide unprecedented speed and memory for solving this complex problem, and new software will be written to treat the coupled fluid, structure and trajectory calculations as part of a single code. Verification and validation experiments have been proposed to provide the necessary confidence in the computations.

Download or read book Observations on Parachute Scale Factors for Modeling Parachute Deployment and Steady State Performance written by William P. Ludtke and published by . This book was released on 1979 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: A New approach to the scaling of parachute performance is presented, based upon variables inherent in the inflation process such as weight, time, geometry, etc. Limitations of conventional scaling parameters such as Reynold's, Froude, and Mach numbers as applied to parachutes are discussed. Examples of parachute inflation and steady state performance are correlated with a scale factor designated as a Mass Ratio, which is the ratio of the system mass to a mass of atmosphere associated with the parachute size, inflation time, altitude and deployment velocity. For advanced opening shock analyses, the concept of variable mass ratio during canopy inflation is proposed, and the effects of partial canopy inflation at suspension line stretch are discussed. Although the solid cloth types of parachutes are primarily used as examples, the ideas of mass ratio, initial area, and analysis techniques are applicable to all types of parachutes. (Author).

Download or read book Modeling and Simulation of the Inflation of Supersonic Parachute for Mars Landing written by Zhengyu Huang and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The numerical simulation of nonlinear fluid-structure interaction problems is significant in many engineering and scientific applications. Examples include aircraft flutter in transonic flows, underwater implosions, pipeline explosions, flapping wings for micro aerial vehicles, and biomedical flows in heart and blood vessels, reactor fuel performance and so on. These problems are generally highly nonlinear, feature multiple scales and strong coupling effects, and might require heterogeneous discretizations for the various physics subsystems. Developing high-fidelity multidisciplinary models for such problem, with an emphasis on real world applications, is the motivation of the thesis. More specifically, the goal is to understand the supersonic parachute inflation dynamics for Mars landing. In 1972, NASA recorded the 1st known instance of a successful parachute operation in the wake of a blunt object at supersonic speeds, during the preparation for the Viking missions to Mars. However, the problem still remains open. "The stress analysis of the canopy cloth is extremely complicated, since maximum stresses occur during opening, which is when the shape and load change rapidly." (Houmard, the Goodyear Aerospace Corporation, 1972) "Technology in parachute structural analysis is far from desirable and no authoritative individual and/or company can really be said to exist." (Alley, NASA, 1972) "No information exists fully explaining parachute behavior in supersonic flow." (Lingard, UK-based Vorticity Ltd, 2010) This thesis first describes an embedded boundary framework for highly nonlinear fluid-structure interaction problems. This is based on the Finite Volume method with Exact two-material Riemann Problems (FIVER), developed in Farhat Research Group [1], and capable of handling evolving material interfaces, including structural fracture. The framework further incorporates a parallel adaptive mesh refinement based on newest vertex bisection, therefore, becomes more efficient for problems with large structure deformations and evolving shock waves. And several modifications are proposed to relieve the ill-conditioning near the fluid-structure interface due to extrapolations, hence, the framework becomes mesh position and orientation independent and delivers smooth pressure coefficient and skin-friction coefficient. Furthermore, this thesis makes a variety of contributions to make the framework more suitable for the parachute inflation simulations. These contributions include a homogeneous porous wall model to capture the porous effect of the canopy on the fluid, and a suspension line treatment that allows for the interactions of the sub-grid scale suspension lines with the flow. Finally, several full-size parachute inflation simulations in the low-density, low-pressure Mars atmosphere are conducted. The computed drag performance is in good agreement with the data collected by the NASA Curiosity Rover during its Mars atmospheric entry. Besides, basic material failure analysis is conducted, which indicates the parachute decelerator system of Curiosity survives with a safety factor about 5.0. This framework demonstrates the potential of using CFD and FSI based simulation tools for the future supersonic parachute design. In addition to the parachute project, several other related projects are reported in this thesis. The first one is a new approach to learning constitutive relations from indirect observation data and its uncertainty quantification for material coupons, such as parachute fabric. In contrast to direct input-output data curve-fitting, this approach focuses on problems, where obtaining comprehensive model input-output data is difficult. But indirect data, like deflections of the structure coupon under different load conditions, are available. Traditional approaches, such as the finite element method, bridge the indirect data with neural network-based~(or its counterparts) constitutive relation models. Its mathematical properties, like accuracy and applicability properties of the approach and the strength of neural networks, are thoroughly studied. Another project aims to extend the multiphysics framework to higher order. Arbitrarily high-order, stable, partitioned solvers are constructed, where different subsystems are modeled and discretized separately, and the resulting equations are solved independently. These solvers are used with the discontinuous Galerkin method for fluid-structure interaction problems with moderate structure deformations.

Download or read book Development of a Total Trajectory Simulation for Single Recovery Parachute Systems Volume I Analytical Model and Computer Program Design Rationale written by Helmut G. Heinrich and published by . This book was released on 1973 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method of total trajectory simulation was established which is based on the governing equations of the various phases of an airdrop or recovery system. In view of these equations, a computer program capable of predicting the performance characteristics of a parachute-load system from the instant of initiation to the moment of landing was established. Calculations were performed for a number of different aerial delivery systems. The calculated results fall well within the broad ranges of expected performance, based upon a familiarity with field test results. (Modified author abstract).

Download or read book Development of a Total Trajectory Simulation for Single Recovery Parachute Systems Volume II Calculation Procedures and Computer Program written by and published by . This book was released on 1973 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method of total trajectory simulation was established which is based on the governing equations of the various phases of an airdrop or recovery system. In view of these equations, a computer program capable of predicting the performance characteristics of a parachute-load system from the instant of initiation to the moment of landing was established. Calculations were performed for a number of different aerial delivery systems. The calculated results fall well within the broad ranges of expected performance, based upon familiarity with field test results. In Volume I, simulation methods and numerical calculation results are presented; in Volume II details of the calculation procedures and computer program are presented.

Download or read book Advanced Structural Modeling for Fully Coupled Parachute Dynamics written by and published by . This book was released on 2002 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this project has been to advance the state-of-the-art in performing fluid-structure interaction (FSI) simulations of parachute systems. This capability is being used by the Army to evaluate the dynamic behavior of new and existing airdrop systems. Airdrop systems have traditionally been designed using semi-empirical methods supplemented by extensive testing, which is time consuming and expensive. Computer simulation provides a cost effective alternative to this approach. FSI simulations of airdrop systems require coupling of computational structural and fluid dynamics models. These simulations are very computationally intensive and therefore parallel computational methods are essential. Specifics objectives addressed under this project focused on both the structural mechanics and parallel requirements; the required fluid dynamics component has been performed collaboratively at Rice University under a separate effort. The project accomplishments are classified into the following three general areas that are described in detail in this report: 1. Development of parallel structural algorithms required for FSI simulations 2. Development of new structural mechanics theory for modeling airdrop systems 3. Performance of large-scale computer simulations of Army airdrop systems.

Download or read book Design and Performance of a Parachute for the Recovery of a 760 lb Payload written by and published by . This book was released on 1991 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: A 26-ft-diameter ribbon parachute deployed using a pilot parachute system has been developed at Sandia National Laboratories for the recovery of a 760-lb payload released at subsonic and transonic speeds. The wide range of deployment dynamic pressures led to the design, utilizing wind tunnel testing and computer simulation, of a unique pilot parachute system verified in full-scale flight tests. Performance data from 20 full-scale flight tests were used to evaluate system performance and structural validity. The concical ribbon parachute design chosen for this development effort follows the practice of previous Sandia National Laboratory parachute development programs for high performance airdropped payloads. The design process for this parachute system included a tradeoff study to evaluate and compare the performance between an equivalent drag area 26-foot-diameter single parachute system and a cluster system of three 14-ft-diameter parachutes. The results showed a small advantage for the cluster system in inflation and initial deceleration characteristics. However, the higher cost, higher weight, greater packing complexity and greater risk involved in the development of the cluster system outweighed the performance advantages and led to the choice of the 26-ft-diameter parachute as the baseline design for the development. This paper describes the design and performance of the 26-ft-diameter parachute which was chosen for the recovery of a 760-lb payload. The results of 20 full-scale flight test of this parachute system are summarized. 8 refs., 13 figs., 2 tabs.

Download or read book A Computational Fluid Dynamics Study on the Aerodynamic Performance of Ram air Parachutes written by Angelo A. Fonseca Pazmiño and published by . This book was released on 2018 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: The modeling of the ram-air parachute presents challenges in the prediction of the inflight geometry, as there is a strong interaction between the flow field and parachute structure. This thesis presents the development of a CAD design and CFD methodology to the simulation of ram-air parachutes in steady-state conditions. Starting from a 2D rib drawing, methods were developed to approximate the 3D geometry and efficiently model the parachute as a rigid and impermeable body. The use of distortions was implemented on a 2D, pseudo-2D, and 3D model to enhance their behavior during a real flight. The SST turbulence model was chosen for the modeling of these designs because of its suitability to predict flow separation and reattachment from adverse pressure gradients. The high complexity of the 3D model is handled using appropriate boundary conditions and cleaning geometric tools within the CFD software. Visualization of the fluid flow parameters such as lift and drag coefficients at different angles of attack allow to evaluate aerodynamic performance at the specified flight conditions and provide clear trends for best model shapes. The computational results were compared to other experimental and numerical studies.

Download or read book Simulation and Modeling Techniques for Parachute Fluid structure Interactions written by Keith R. Stein and published by . This book was released on 1999 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design Modeling and Testing of a Cascaded Heading Stabilization Controller for a Cruciform Parachute System written by Jackson Daniel and published by . This book was released on 2021 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work presented in this thesis pertains to the advancement of an existing novel aerial delivery platform that utilizes a cruciform parachute canopy. The cruciform design represents a compromise between the simplicity and affordability of unguided parachute systems and the high performance and precision of complex, expensive parafoil systems. The improvements made to the platform can be summarized in two main contributions. First, through the use of a systematic controller design methodology and simulation-focused experimental plan, an effective heading stabilization controller can be developed without requiring substantial amounts of free-flight testing. Second, a cascaded control structure is proposed to facilitate enhanced performance in disturbance rejection and setpoint tracking of the parachute heading compared to the existing single-loop PID controller. This approach to controller design permits rapid deployment of cruciform systems of varying type and scale suited to specific operational requirements.

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.

Download or read book Wake Properties Behind an Ejection Seat Escape System and Aerodynamic Characteristics with Stabilization Parachutes at Mach Numbers from 0 6 to 1 5 written by David E. A. Reichenau and published by . This book was released on 1971 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: A test was conducted in the Propulsion Wind Tunnel (16T) of the Propulsion Wind Tunnel Facility to determine the flow field in the wake of an ejection seat escape system at transonic flight conditions, and to determine the performance characteristics of a stabilization parachute attached to the back of the ejection seat model. The results were obtained for both simulated rocket-off and rocket-on conditions through a model angle-of-attack range from 0 to 30 deg. High pressure air was used to simulate the escape rocket jet plume at a sea-level altitude. The results show that the ejection seat model was statically unstable, but became longitudinally stable with the parachute for the test range investigated. (Author).