Download or read book Prediction of Propeller Blade Pressure Distribution with a Panel Method written by Cheng I. Yang and published by . This book was released on 1990 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Panel methods and their underlying theory are reviewed with regard to hydrodynamic analysis of propeller performance. Green's identity is used to convert the differential Laplace's equation into an integral equation. The velocity potential on the surface of the lifting body can be expressed by integrating the potential induced by source/doublet singularities distributed over the surface. The numerical discretizations of the boundary surface, singularity distributions, the integral equation, and the formulation of the panel method are discussed. The advantages of the application of panel methods in viscous/inviscid interactive procedures and propeller blade design are outlined. Results of propeller blade analysis with the panel method are presented, comparing the prediction of the VSAERO panel method and a vortex lattice method with experimental data. The panel method, which includes consideration of propeller hub effects, gives predictions in good agreement with experimental data. Keywords: Marine propellers hydrodynamic characteristics. (edc).

Download or read book An Improved Panel Method for the Prediction of Performance of Ducted Propellers written by Hongyang Fan and published by . This book was released on 2015 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: An improved perturbation potential based lower order panel method is applied to the three dimensional problems of flow around ducts and ducted propellers. One significant development of this method is the application of full wake alignment scheme in which the trailing vortex wake sheets of the blades are aligned with the local flow velocity by also considering the effects of duct and duct wake. A process of repaneling the duct is simultaneously introduced to improve the accuracy of evaluation of the method. The results from the improved wake model are compared with those from a simplified wake alignment scheme (PSF-2 type scheme). At the same time, full-blown RANS simulations of the three dimensional problem are conducted. The forces, i.e. thrust and torque on the propeller predicted by the present panel method under the improved wake alignment model show good agreement both with experimental measurements, a hybrid method developed by the Ocean Engineering Group of UT Austin, and the full blown RANS simulations. Moreover, detailed pressure distribution on the blades and duct are compared among the various methods. The interactive method which couples the lower order panel method with a two dimensional boundary layer solver through a wall transpiration model is also introduced. An assumption of two dimensional flow is made on the individual stations of a three dimensional geometries and the coupling is applied in a stripwise manner by including the interaction effects from other strips. The interactive method is then validated through the cases of bare ducts and ducted propellers. An important improvement is also made on the extension scheme for hydrofoils and propeller blades with blunt trailing edge. A more physical criterion has been established for determining the location of cut planes or the starting points of the extension. The extension scheme is applied to both axisymmetric problems and fully three dimensional problems. Correlations of results with experimental measurements and RANS simulations are presented.

Download or read book Further Measurements of Model Propeller Pressure Distributions Using a Novel Technique written by Stuart D. Jessup and published by . This book was released on 1986 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Model propeller blade pressure distributions were measured using a novel technique. A single pressure gage was installed at a radial position to measure pressures at numerous chordwise locations through pressure taps and connecting channels. The technique resulted in accurate, detailed pressure distributions along two radial positions using two pressure gages. The major advantage of this technique is the ability to make measurements in the thin parts of the blade with high potential accuracy, and no disruption to the measuring surface, except for the orifice hole. The relatively along test time required to collect the data is the disadvantage. Keywords: Marine Propeller, Propeller Research Pressure Distribution, Model Experiments.

Download or read book Pressure Distribution on Propeller Blade Surface Using Numerical Lifting Surface Theory written by Ki-Han Kim and published by . This book was released on 1985 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: A procedure and numerical results are presented for the prediction of the steady pressure distribution on a rotating propeller blade surface based on lifting surface theory. A computer code, named the Propeller Steady Pressure (PSP) program, has been developed by extending the existing propeller analysis program, PSF, based on vortex/source lattice techniques, developed at the Mass. Inst. of Technology. Predictions by PSP are compared with selected experimental values that are believed to be accurately and reliably measured. Comparisons are also made between PSP predictions and other theoretical predictions. The predictions by PSP are generally in good agreement with experimental values and with other prediction methods except for the tip region where current procedures may not be accurate enough to represent the actual flow. Keywords include: Marine hydrodynamics, Blade pressure, Lifting surface theory and Discrete vortex/source method.

Download or read book A Potential Based Panel Method for the Analysis of Marine Propellers in Steady Flow written by Jin-Tae Lee and published by . This book was released on 1987 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: A surface panel method suitable for the analysis of marine propellers is developed and applied to various geometries to demonstrate its effectiveness. A reliable pressure distribution around a marine propeller, especially near the leading edge of the blade, is obtained. Hub effects are naturally included by distributing panels on the hub surface. Detailed study of the flows at the trailing edge near the tip suggests a pressure Kutta condition, which requires the pressures of the last panels at the trailing edge be equal. Due to the nonlinear aspect of the pressure Kutta condition, an iterative process is employed. An efficient approximation of the ultimate wake is achieved by replacing it with a sink disk a the beginning of the ultimate wake. The sample geometries include an ellipsoid at zero angle of attack, a circular planform wing, a rectangular planform wing with varying sweep angles, a wing-body configuration, a long axisymmetric duct, and a marine propeller. Calculated pressure distributions around the wing-body configuration are in excellent agreement with the experimental data. Calculated thrust and torque for the propeller agree well experimental results.

Download or read book Propeller Blade Pressure Distribution Due to Loading and Thickness Effects written by S. Tsakonas and published by . This book was released on 1976 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: A theoretical approach is developed and a computational procedure adaptable to a high speed digital computer is established for the evaluation of the blade pressure distribution of a marine propeller due to thickness and loading effects. The dual role of the blade thickness is considered. The contribution of the nonplanar thickness to the propeller loading and pressure distribution and the effect of the flow distortion thickness are studied by means of the thin body approximation. The surface integral equation which relates the unknown loading to the known velocity distribution on the blades is solved by the mode approach in conjunction with the lift operator technique. The analysis treats both design and off-design conditions in steady-state and unsteady flows, and the proper chordwise modes are selected for each condition. The numerical solution yields the blade loading and resulting hydrodynamic forces and moments and blade bending moments, and, in addition, the blade pressure distributions on each blade face due to both loading and thickness effects, thus providing information necessary for the prediction of cavitation inception. Calculations have been performed for a set of three 3-bladed propellers of different EAR operating in a screen-generated wake, for comparison with experimental data. (Author).

Download or read book Twenty Second Symposium on Naval Hydrodynamics written by National Research Council and published by National Academies Press. This book was released on 2000-03-02 with total page 1039 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Twenty-Second Symposium on Naval Hydrodynamics was held in Washington, D.C., from August 9-14, 1998. It coincided with the 100th anniversary of the David Taylor Model Basin. This international symposium was organized jointly by the Office of Naval Research (Mechanics and Energy Conversion S&T Division), the National Research Council (Naval Studies Board), and the Naval Surface Warfare Center, Carderock Division (David Taylor Model Basin). This biennial symposium promotes the technical exchange of naval research developments of common interest to all the countries of the world. The forum encourages both formal and informal discussion of the presented papers, and the occasion provides an opportunity for direct communication between international peers.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ship Resistance and Propulsion written by Anthony F. Molland and published by Cambridge University Press. This book was released on 2011-08-08 with total page 569 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by experts in the ship design field, this book provides a comprehensive approach to evaluating ship resistance and propulsion.

Download or read book Method to Determine Pressure Distribution on a Ship Propeller Blade Operating in a Nonuniform Velocity Field Using a Model that Accounts for Unsteady Hydrodynamic Processes Doctoral Thesis written by Jan Szantyr and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Journal of Hydrodynamics written by and published by . This book was released on 1995 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement and Prediction of Propeller Blade Surface Pressure Distributions written by David Tudor Owen and published by . This book was released on 1989 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Twenty Second Symposium on Naval Hydrodynamics written by National Research Council and published by National Academies Press. This book was released on 2000-02-02 with total page 1039 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Twenty-Second Symposium on Naval Hydrodynamics was held in Washington, D.C., from August 9-14, 1998. It coincided with the 100th anniversary of the David Taylor Model Basin. This international symposium was organized jointly by the Office of Naval Research (Mechanics and Energy Conversion S&T Division), the National Research Council (Naval Studies Board), and the Naval Surface Warfare Center, Carderock Division (David Taylor Model Basin). This biennial symposium promotes the technical exchange of naval research developments of common interest to all the countries of the world. The forum encourages both formal and informal discussion of the presented papers, and the occasion provides an opportunity for direct communication between international peers.

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 Measurement of the Pressure Distribution on Two Model Propellers written by Stuart D. Jessup and published by . This book was released on 1982 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Propellers shafting 94 Symposium written by and published by . This book was released on 1994 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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.