Download or read book Computational Improvements to Predict Propeller Performance at Off Design Conditions written by William Earle Duncan and published by . This book was released on 2002 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Propeller Blade Stress Estimates Using Lifting Line Theory written by Brenden P. Epps and published by . This book was released on 2010 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: OPENPROP, an open-source computational tool for the design and analysis of propellers and horizontal-axis turbines, is extended to provide estimates of normal stresses in the blades for both on- and off-design operating conditions. The numerical model is based on propeller lifting theory, and the present implementation of the code includes an analysis capability to estimate the off-design performance of the propeller or turbine and to make blade stress predictions. As an example, we present the design and performance of a two-bladed propeller. Experimental measurements of the propeller performance over a wide range of off-design operating conditions agree with performance predictions. Estimates of the blade stress are given for on-design and off design operating states of the propeller.

Download or read book Computational Predictions of the Performance Wright bent End Propellers written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-09-19 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational analysis of two 1911 Wright brothers 'Bent End' wooden propeller reproductions have been performed and compared with experimental test results from the Langley Full Scale Wind Tunnel. The purpose of the analysis was to check the consistency of the experimental results and to validate the reliability of the tests. This report is one part of the project on the propeller performance research of the Wright 'Bent End' propellers, intend to document the Wright brothers' pioneering propeller design contributions. Two computer codes were used in the computational predictions. The FLO-MG Navier-Stokes code is a CFD (Computational Fluid Dynamics) code based on the Navier-Stokes Equations. It is mainly used to compute the lift coefficient and the drag coefficient at specified angles of attack at different radii. Those calculated data are the intermediate results of the computation and a part of the necessary input for the Propeller Design Analysis Code (based on Adkins and Libeck method), which is a propeller design code used to compute the propeller thrust coefficient, the propeller power coefficient and the propeller propulsive efficiency.Wang, Xiang-Yu and Ash, Robert L. and Bobbitt, Percy J. and Prior, Edwin (Technical Monitor)Langley Research CenterPROPELLER EFFICIENCY; PROPELLER BLADES; COMPUTATIONAL FLUID DYNAMICS; WIND TUNNEL TESTS; NAVIER-STOKES EQUATION; COMPUTERIZED SIMULATION; APPLICATIONS PROGRAMS (COMPUTERS); LIFT; AERODYNAMIC DRAG

Download or read book Singularity Methods for Rapid Design and Analysis of Cross flow Propellers and Turbines written by Bernard T. Roesler and published by . This book was released on 2017 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: In their respective quests for higher energy efficiency and greater power extraction, the marine transportation and marine hydrokinetic industries have developed a class of devices known as cross-flow propellers and turbines. To predict the performance of these devices, engineers require accurate computational models. Traditional Reynolds-averaged Navier- Stokes equation (RANS) solvers provide an accurate, detailed description of the fluid flow, but the transient solution for each design iteration often requires a number of days to complete. At the other end of the spectrum, lumped airfoil models are fast, but accuracy is limited to certain design geometries and operating conditions. This thesis applies the vortex lattice method (VLM) to the cross-flow rotor design problem, to fill the need for a computational method to analyze cross-flow rotors that is at once fast, accurate, and robust. We first explore the standard lumped airfoil model as applied to a cross-flow propeller. We perform a design study to demonstrate the applicability of the model to design a propeller for an inland waterway vessel, and we conduct a model-scale experiment of a novel propeller design in order to validate our model for the propeller case. Through comparison with RANS simulations, however, we find the lumped airfoil model to be inaccurate for the turbine case. We then present the vortex lattice method, which includes implementation features to improve accuracy and computational efficiency for the cross-flow rotor design problem. We compare our VLM results to RANS solutions to demonstrate our significant improvement over the state-of-the-art lumped airfoil methods. Finally, we investigate the sensitivity of the model to changes in each of its parameters in order to determine the robustness of our model. Throughout this thesis, we follow the cycle of engineering design to make observations of the operation of cross-flow devices, gain insights on the physical phenomena governing their operation, and incorporate those insights into our models.

Download or read book Marine Propulsors written by Sverre Steen and published by MDPI. This book was released on 2018-10-10 with total page 355 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue "Marine Propulsors" that was published in JMSE

Download or read book Twenty First Symposium on Naval Hydrodynamics written by National Research Council and published by National Academies Press. This book was released on 1997-09-11 with total page 1100 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Selected Papers from the Sixth International Symposium on Marine Propulsors written by Sverre Steen and published by MDPI. This book was released on 2020-12-29 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine propulsors are key components of the many thousands of ships and boats operating in oceans, lakes, and rivers around the world. The performance of propulsors are important for the environmental impact of ships, underwater noise impact on aquatic fauna, and crew and passenger comfort and safety. This book presents nineteen papers devoted to the hydrodynamics of different types of marine propulsors (conventional propellers, thrusters, and novel solutions). Most of the papers are extended papers from the sixth International Symposium on Marine Propulsors (SMP 2019). Several of the papers deal with cavitation, vortices, and energy saving devices. The papers present high-quality research performed using Computational Fluid Dynamics (CFD) and Experimental Fluid Dynamics (EFD) as well Artificial Intelligence (AI).

Download or read book Frontiers Of Computational Fluid Dynamics 2006 written by Mohamed M Hafez and published by World Scientific. This book was released on 2005-12-07 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series of volumes to which this book belongs honors contributors who have made a major impact in computational fluid dynamics. This fourth volume in the series is dedicated to David Caughey on the occasion of his 60th birthday. The first volume was published in 1994 and was dedicated to Prof Antony Jameson. The second, dedicated to Earl Murman, was published in 1998. The third volume was dedicated to Robert MacCormack in 2002.Written by leading researchers from academia, government laboratories, and industry, the contributions in this volume present descriptions of the latest developments in techniques for numerical analysis of fluid flow problems, as well as applications to important problems in industry.

Download or read book Marine propeller performance written by A. Baquero and published by . This book was released on 1999 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Verification and Validation in Scientific Computing written by William L. Oberkampf and published by Cambridge University Press. This book was released on 2010-10-14 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in scientific computing have made modelling and simulation an important part of the decision-making process in engineering, science, and public policy. This book provides a comprehensive and systematic development of the basic concepts, principles, and procedures for verification and validation of models and simulations. The emphasis is placed on models that are described by partial differential and integral equations and the simulations that result from their numerical solution. The methods described can be applied to a wide range of technical fields, from the physical sciences, engineering and technology and industry, through to environmental regulations and safety, product and plant safety, financial investing, and governmental regulations. This book will be genuinely welcomed by researchers, practitioners, and decision makers in a broad range of fields, who seek to improve the credibility and reliability of simulation results. It will also be appropriate either for university courses or for independent study.

Download or read book Marine Propellers and Propulsion written by John Carlton and published by Butterworth-Heinemann. This book was released on 2012-10-30 with total page 539 pages. Available in PDF, EPUB and Kindle. Book excerpt: The early development of the screw propeller. Propeller geometry. The propeller environment. The ship wake field, propeller performance characteristics.

Download or read book Practical Ship Hydrodynamics written by Volker Bertram and published by Elsevier. This book was released on 2012 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: Practical Ship Hydrodynamics provides a comprehensive overview of hydrodynamic experimental and numerical methods for ship resistance and propulsion, maneuvering, seakeeping and vibration. Beginning with an overview of problems and approaches, including the basics of modeling and full scale testing, expert author Volker Bertram introduces the marine applications of computational fluid dynamics and boundary element methods. Expanded and updated, this new edition includes: Otherwise disparate information on the factors affecting ship hydrodynamics, combined to provide one practical, go-to resource. Full coverage of new developments in computational methods and model testing techniques relating to marine design and development. New chapters on hydrodynamic aspects of ship vibrations and hydrodynamic options for fuel efficiency, and increased coverage of simple design estimates of hydrodynamic quantities such as resistance and wake fraction. With a strong focus on essential background for real-life modeling, this book is an ideal reference for practicing naval architects and graduate students.

Download or read book Design and Performance Evaluation of a Propeller written by Balaji Jayanth Venkatesh and published by . This book was released on 2012 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NBS Special Publication written by and published by . This book was released on 1978 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Propeller Performance Analysis Using Lifting Line Theory written by Kevin Michael Flood and published by . This book was released on 2008 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Propellers are typically optimized to provide the maximum thrust for the minimum torque at a specific number of revolutions per minute (RPM) at a particular ship speed. This process allows ships to efficiently travel at their design speed. However, it is useful to know how the propeller performs during off-design conditions. This is especially true for naval warships whose missions require them to perform at a wide range of speeds. Currently the Open-source Propeller Design and Analysis Program can design and analyze a propeller only at a given operating condition (i.e. a given propeller RPM and thrust). If these values are varied, the program will design a new optimal propeller for the given inputs. The purpose of this thesis is to take a propeller that is designed for a given case and analyze how it will behave in off-design conditions. Propeller performance is analyzed using non-dimensional curves that depict thrust, torque, and efficiency as functions of the propeller speed of advance. The first step in producing the open water diagram is to use lifting line theory to characterize the propeller blades. The bound circulation on the lifting line is a function of the blade geometry along with the blade velocity (both rotational and axial). Lerbs provided a method to evaluate the circulation for a given set of these conditions. This thesis implements Lerbs method using MATLAB® code to allow for fast and accurate modeling of circulation distributions and induced velocities for a wide range of operating conditions. These values are then used to calculate the forces and efficiency of the propeller. The program shows good agreement with experimental data.

Download or read book RANS Computation of Propeller Tip Vortex Flow for Steady and Unsteady Cases written by Md. Shafiul Azam Mintu and published by . This book was released on 2011 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Computational Tool for the Rapid Design and Prototyping of Propellers for Underwater Vehicles written by Kathryn Port D'Epagnier and published by . This book was released on 2007 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) The first study analyzes propeller thruster performance characteristics for an off-the-shelf propeller, while the second study demonstrates the process for propeller optimization-from the initial design to the final file that can be read by a 3D printer. The third study reviews the complete process of the design and production of an AUV propeller. Thus, OpenPVL performs a variety of operations as a propeller lifting line code in streamlining the propeller optimization and prototyping process.