Download or read book Computational Fluid Dynamics Modeling of Parachute Clusters written by and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A computational tool that models the terminal descent characteristics of a single or a cluster of parachutes is a technology that is needed by parachute designers and engineers. As part of a technology program annex (TPA), a joint effort between the U.S. Army Natick Research, Development, and Engineering Center (RRDEC) and the U.S. Army Research Laboratory (ARL) to develop this computational tool is now under way. As a first effort, attempts are being made to analyze both two-dimensional (2- D) and three-dimensional (3-D) flow fields around a parachute using a coupling procedure in which the fluid dynamics are coupled to 2-D and 3-D structural dynamic (SD) codes. This effort uses computational fluid dynamic (CFD) codes to calculate a pressure field, which is then used as an input load for the SD code. Specifically, this report presents the methods and results of the flow field plus the structural characteristics of a single axisymmetric parachute and a 3-D gore configuration for the terminal descent velocity. Computed results have been obtained using the payload weight and unstretched constructed geometry of the canopies as input. Significant progress has been made in determining the terminal descent flow field along with the terminal shape of the parachute. A discussion of the fluid and structural dynamics codes, coupling procedure, and the associated technical difficulties is presented. Examples of the codes' current capabilities are shown.
Download or read book Computational Fluid Dynamics Modeling of Parachute Clusters written by and published by . This book was released on 1997 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: A computational tool that models the terminal descent characteristics of a single or a cluster of parachutes is a technology that is needed by parachute designers and engineers. As part of a technology program annex (TPA), a joint effort between the U.S. Army Natick Research, Development, and Engineering Center (RRDEC) and the U.S. Army Research Laboratory (ARL) to develop this computational tool is now under way. As a first effort, attempts are being made to analyze both two-dimensional (2- D) and three-dimensional (3-D) flow fields around a parachute using a coupling procedure in which the fluid dynamics are coupled to 2-D and 3-D structural dynamic (SD) codes. This effort uses computational fluid dynamic (CFD) codes to calculate a pressure field, which is then used as an input load for the SD code. Specifically, this report presents the methods and results of the flow field plus the structural characteristics of a single axisymmetric parachute and a 3-D gore configuration for the terminal descent velocity. Computed results have been obtained using the payload weight and unstretched constructed geometry of the canopies as input. Significant progress has been made in determining the terminal descent flow field along with the terminal shape of the parachute. A discussion of the fluid and structural dynamics codes, coupling procedure, and the associated technical difficulties is presented. Examples of the codes' current capabilities are shown.
Download or read book Fluid Dynamics Computational Modeling and Applications written by L. Hector Juarez and published by BoD – Books on Demand. This book was released on 2012-02-24 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt: The content of this book covers several up-to-date topics in fluid dynamics, computational modeling and its applications, and it is intended to serve as a general reference for scientists, engineers, and graduate students. The book is comprised of 30 chapters divided into 5 parts, which include: winds, building and risk prevention; multiphase flow, structures and gases; heat transfer, combustion and energy; medical and biomechanical applications; and other important themes. This book also provides a comprehensive overview of computational fluid dynamics and applications, without excluding experimental and theoretical aspects.
Download or read book 3 D Parachute Descent Analysis Using Coupled Computational Fluid Dynamic and Structural Codes written by and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A computational tool that models the terminal descent characteristics of a single or a cluster of parachutes is a technology that is needed by parachute designers and engineers. As part of a technology program annex (TPA), a joint effort between the U.S. Army Natick Research, Development, and Engineering Center (NRDEC) and the U.S. Army Research Laboratory (ARL) to develop this computational tool is now under way. As a first effort, attempts are being made to analyze both two-dimensional (2- D) and three-dimensional (3-D) flow fields around a parachute using a coupling procedure in which the fluid dynamics are coupled to 2-D and 3-D structural dynamic (SD) codes. This effort uses computational fluid dynamic (CFD) codes to calculate a pressure field, which is then used as an input load for the SD code. Specifically, this report presents the methods and results of the flow field plus the structural characteristics of a single axisymmetric parachute and a 3-D gore configuration for the terminal descent velocity. Computed results have been obtained using the payload weight and unstretched constructed geometry of the canopies as input. Significant progress has been made in determining the terminal descent flow field along with the terminal shape of the parachute. A discussion of the fluid and structural dynamics codes, coupling procedure, and the associated technical difficulties is presented. Examples of the codes' current capabilities are shown.
Download or read book A Computational Model that Couples Aerodynamic and Structural Dynamic Behavior of Parachutes During the Opening Process written by Keith R. Stein and published by . This book was released on 1993 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: In parachute research, the canopy inflation process in the least understood and most complex to model. Unfortunately, it is during the opening process that the canopy often experiences the largest deformations and loadings. The complexity of modelling the opening process stems from the coupling between the structural dynamics of the canopy, lines and payload with the aerodynamics of the surrounding fluid medium. The addition of a computational capability to model the coupled opening behavior would greatly assist in the understanding of the canopy inflation process.
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 New Structural Model for Parachute Inflation Simulations written by and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this project has been to develop a new robust structural model that is being coupled with existing computational fluid dynamics (CFD) codes to accurately simulate the dynamics of parachute and parafoil systems. This research will allow the Army to reduce the time and cost of developing new airdrop systems and retrofitting existing systems for new applications. Parachute dynamics is an extremely complex process. This process is governed by nonlinear time dependent coupling between the parachute and surrounding airflow and involves large canopy shape changes and unconstrained motion of the parachute in the fluid medium. To successfully simulate this complex process, a robust structural model is essential. The following capabilities were added to the structural model: (1) membrane wrinkling, (2) material orthotropy, (3) local bending and damping elements, (4) user defined time dependent element properties, (5) various nonlinear transient solution algorithms, (6) approximate fluid forces, (7) stress projection algorithms, and (8) local nodal coordinate systems. It has been demonstrated that large scale finite element modeling of parachute dynamics is feasible using this structural model. Significant transfer of this basic research was accomplished. New structural model features have continuously been incorporated into a finite element code which has been used extensively by Army engineers to perform simulations of Army parachute systems.
Download or read book Parachute Inflation A Problem in Aeroelasticity written by and published by . This book was released on 1994 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: In parachute research, canopy inflation is the least understood and most complex process to model. Unfortunately, it is during the opening process that the canopy experiences the largest deformations and loadings. The complexity of modeling the opening process stems from the coupling between the structural dynamics of the canopy, lines plus payload and the aerodynamics of the surrounding fluid medium. The addition of a computational capability to model the coupled opening behavior would greatly assist in understanding the canopy inflation process. Ongoing research at the U.S. Army Natick Research, Development and Engineering Center (Natick) focuses on this coupled problem. The solution to this problem will assist in the development of future U.S. Army airdrop systems, which include the capability of deploying at low altitudes and high speeds. This report describes research at Natick that currently involves coupling a computational fluid dynamics (CFD) code to a mass spring damper (MSD) parachute structural code. The model is described and results are presented.
Download or read book Computational Fluid and Solid Mechanics written by K.J. Bathe and published by Elsevier. This book was released on 2001-05-21 with total page 975 pages. Available in PDF, EPUB and Kindle. Book excerpt: The MIT mission - "to bring together Industry and Academia and to nurture the next generation in computational mechanics is of great importance to reach the new level of mathematical modeling and numerical solution and to provide an exciting research environment for the next generation in computational mechanics." Mathematical modeling and numerical solution is today firmly established in science and engineering. Research conducted in almost all branches of scientific investigations and the design of systems in practically all disciplines of engineering can not be pursued effectively without, frequently, intensive analysis based on numerical computations.The world we live in has been classified by the human mind, for descriptive and analysis purposes, to consist of fluids and solids, continua and molecules; and the analyses of fluids and solids at the continuum and molecular scales have traditionally been pursued separately. Fundamentally, however, there are only molecules and particles for any material that interact on the microscopic and macroscopic scales. Therefore, to unify the analysis of physical systems and to reach a deeper understanding of the behavior of nature in scientific investigations, and of the behavior of designs in engineering endeavors, a new level of analysis is necessary. This new level of mathematical modeling and numerical solution does not merely involve the analysis of a single medium but must encompass the solution of multi-physics problems involving fluids, solids, and their interactions, involving multi-scale phenomena from the molecular to the macroscopic scales, and must include uncertainties in the given data and the solution results. Nature does not distinguish between fluids and solids and does not ever repeat itself exactly.This new level of analysis must also include, in engineering, the effective optimization of systems, and the modeling and analysis of complete life spans of engineering products, from design to fabrication, to possibly multiple repairs, to end of service.
Download or read book Experimental and Computational Modeling of Parachutes Fluid Dynamics written by and published by . This book was released on 2006 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: The paper consists of two parts devoted correspondingly to the experimental opportunities and results along with the computational methods and results obtained mainly in the Central Aerohydrodynamic Institute (TsAGI).
Download or read book Parachute Inflation written by Keith R. Stein and published by . This book was released on 1994 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt: In parachute research, canopy inflation is the least understood and most complex process to model. Unfortunately, it is during the opening process that the canopy experiences the largest deformations and loadings. The complexity of modeling the opening process stems from the coupling between the structural dynamics of the canopy, lines plus payload and the aerodynamics of the surrounding fluid medium. The addition of a computational capability to model the coupled opening behavior would greatly assist in understanding the canopy inflation process. Ongoing research at the U.S. Army Natick Research, Development and Engineering Center (Natick) focuses on this coupled problem. The solution to this problem will assist in the development of future U.S. Army airdrop systems, which include the capability of deploying at low altitudes and high speeds. This report describes research at Natick that currently involves coupling a computational fluid dynamics (CFD) code to a mass spring damper (MSD) parachute structural code. The model is described and results are presented.
Download or read book Computational Fluid Structure Interaction written by Yuri Bazilevs and published by John Wiley & Sons. This book was released on 2013-01-25 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational Fluid-Structure Interaction: Methods and Applications takes the reader from the fundamentals of computational fluid and solid mechanics to the state-of-the-art in computational FSI methods, special FSI techniques, and solution of real-world problems. Leading experts in the field present the material using a unique approach that combines advanced methods, special techniques, and challenging applications. This book begins with the differential equations governing the fluid and solid mechanics, coupling conditions at the fluid–solid interface, and the basics of the finite element method. It continues with the ALE and space–time FSI methods, spatial discretization and time integration strategies for the coupled FSI equations, solution techniques for the fully-discretized coupled equations, and advanced FSI and space–time methods. It ends with special FSI techniques targeting cardiovascular FSI, parachute FSI, and wind-turbine aerodynamics and FSI. Key features: First book to address the state-of-the-art in computational FSI Combines the fundamentals of computational fluid and solid mechanics, the state-of-the-art in FSI methods, and special FSI techniques targeting challenging classes of real-world problems Covers modern computational mechanics techniques, including stabilized, variational multiscale, and space–time methods, isogeometric analysis, and advanced FSI coupling methods Is in full color, with diagrams illustrating the fundamental concepts and advanced methods and with insightful visualization illustrating the complexities of the problems that can be solved with the FSI methods covered in the book. Authors are award winning, leading global experts in computational FSI, who are known for solving some of the most challenging FSI problems Computational Fluid-Structure Interaction: Methods and Applications is a comprehensive reference for researchers and practicing engineers who would like to advance their existing knowledge on these subjects. It is also an ideal text for graduate and senior-level undergraduate courses in computational fluid mechanics and computational FSI.
Download or read book Frontiers in Computational Fluid Structure Interaction and Flow Simulation written by Tayfun E. Tezduyar and published by Springer. This book was released on 2018-10-26 with total page 493 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational fluid-structure interaction and flow simulation are challenging research areas that bring solution and analysis to many classes of problems in science, engineering, and technology. Young investigators under the age of 40 are conducting much of the frontier research in these areas, some of which is highlighted in this book. The first author of each chapter took the lead role in carrying out the research presented. The topics covered include Computational aerodynamic and FSI analysis of wind turbines, Simulating free-surface FSI and fatigue-damage in wind-turbine structural systems, Aorta flow analysis and heart valve flow and structure analysis, Interaction of multiphase fluids and solid structures, Computational analysis of tire aerodynamics with actual geometry and road contact, and A general-purpose NURBS mesh generation method for complex geometries. This book will be a valuable resource for early-career researchers and students — not only those interested in computational fluid-structure interaction and flow simulation, but also other fields of engineering and science, including fluid mechanics, solid mechanics and computational mathematics – as it will provide them with inspiration and guidance for conducting their own successful research. It will also be of interest to senior researchers looking to learn more about successful research led by those under 40 and possibly offer collaboration to these researchers.
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 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 Advances in Computational Fluid Structure Interaction and Flow Simulation written by Yuri Bazilevs and published by Birkhäuser. This book was released on 2016-10-04 with total page 487 pages. Available in PDF, EPUB and Kindle. Book excerpt: This contributed volume celebrates the work of Tayfun E. Tezduyar on the occasion of his 60th birthday. The articles it contains were born out of the Advances in Computational Fluid-Structure Interaction and Flow Simulation (AFSI 2014) conference, also dedicated to Prof. Tezduyar and held at Waseda University in Tokyo, Japan on March 19-21, 2014. The contributing authors represent a group of international experts in the field who discuss recent trends and new directions in computational fluid dynamics (CFD) and fluid-structure interaction (FSI). Organized into seven distinct parts arranged by thematic topics, the papers included cover basic methods and applications of CFD, flows with moving boundaries and interfaces, phase-field modeling, computer science and high-performance computing (HPC) aspects of flow simulation, mathematical methods, biomedical applications, and FSI. Researchers, practitioners, and advanced graduate students working on CFD, FSI, and related topics will find this collection to be a definitive and valuable resource.
Download or read book Drag and Dynamics of Single and Clustered Parachutes in Freestream and with Wake and Ground Effects written by Helmut G. Heinrich and published by . This book was released on 1966 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results of wind tunnel studies concerned with transient and steady state performance of single and clustered parachutes in cargo extraction systems are presented. In Part 1, circular flat and ringslot canopies singly suspended and in clusters of 2, 3, and 4, were deployed in freestream, in the wake of an aircraft, and near a simulated ground. As a further means of analysis, wake pressure surveys were performed on the DHC-4 Caribou and the C-130 Hercules aircraft and are presented in Part 2.
