Download or read book A Method for the Design of Contra rotating Propellers written by Knut J. Minsaas and published by . This book was released on 1971 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Numerical Method for the Design and Analysis of Counter rotating Propellers written by Scott Charles Playle and published by . This book was released on 1984 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design of Contra rotating Propellers by Circulation Theory and Model Tests written by William M. Devlin and published by . This book was released on 1962 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis and Experiments for Contra rotating Propeller written by Eyal Kravitz and published by . This book was released on 2011 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contra-rotating propellers have renewed interest from the naval architecture community, because of the recent development of electric propulsion drives and podded propulsors. Contrarotating propulsion systems have the hydrodynamic advantages of recovering part of the slipstream rotational energy which would otherwise be lost utilizing a conventional screw propeller system. The application of this type of propulsion becomes even more attractive with the increasing emphasis on fuel economy and the improvement of the propulsive efficiency. OPENPROP is an open source propeller design and analysis code that has been in development at MIT since 2007. This thesis adds another feature to the project with the off design analysis of a contra-rotating propeller set. Based on this code, the thesis offers a comparative analysis of two types of propulsors: a single propeller and a contra-rotating propeller set, which were designed for the DDG-51 destroyer class vessel. This thesis also presents the method for using these off-design analysis results to estimate ship powering requirements and fuel usage. The results show the superiority of the contra-rotating propeller over the traditional single propeller, with increased propeller efficiency of about 9% at the design point and up to 20% at some of the off design states. The annual fuel consumption savings for the DDG-51 equipped with a CRP was a total of 8.8% fuel savings.
Download or read book Design and Cavitation Performance of CRPs written by Dimitrios Laskos and published by . This book was released on 2010 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: Improvement of the propulsive efficiency of ships has always been one of the main objectives for naval architects and marine engineers. Contra-Rotating propellers (CRP) are propulsor configurations offering higher efficiency compared to conventional single propellers by recovering the rotational energy in the propeller slipstream. The application of this type of propulsive device to modern ships becomes even more attractive, considering the recent developments in electric propulsion and the increased emphasis on fuel economy. Propeller design codes are therefore expected to include CRP design capabilities. This thesis describes two methods for designing CRP in the context of lifting-line theory, along with a procedure for predicting the cavitation performance of conventional propellers and CRP. All of the above methods have been implemented numerically and integrated into a computer program developed in MATLAB®. Comparisons of numerical predictions of efficiency between single and contra-rotating propellers, which confirm the superiority of the latter are presented. Physical insight into the increased efficiency of CRP is also obtained by presenting results for the velocity fields induced by these propulsor configurations. In addition, the predicted cavitation patterns, observed on conventional and contra-rotating propellers operating in uniform and non-uniform wakes, show the advantage of CRP with respect to the occurrence of cavitation.
Download or read book On the Design of Counter rotating Propellers written by Kenneth Duns Korkan and published by . This book was released on 1983 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Panel Method for Counter Rotating Propellers written by Shih Hsiung Chen and published by . This book was released on 1988 with total page 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.
Download or read book A Design Method and an Application for Contrarotating Propellers written by and published by . This book was released on 1990 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: A design methodology for contrarotating propellers has been developed based on rational hydromechanics. Three fundamental principles need to be satisfied: momentum, mass, and circulation conservation. Momentum conservation requires the net force generated by the contrarotating propeller to be balanced by the drag of the bare body and the drag due to hull-propulsor interaction. Mass conservation determines the circulation distribution of the aft propeller once the forward propeller circulation distribution is specified. Circulation conservation determines the magnitude of the circulation distribution of the aft propeller to ensure the proper thrust and torque ratios. The effects of the hub boundaries have been taken into account in the design and analysis methods. A contrarotating propeller set was designed for uniform flow at the operating point of the propeller for a high speed surface ship. Open water results show that the performance predictions agree well with the measurements. (KR).
Download or read book Marine Propellers and Propulsion written by John Carlton and published by Elsevier. This book was released on 2011-04-01 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although the propeller lies submerged out of sight, it is a complex component in both the hydrodynamic and structural sense. This book fulfils the need for a comprehensive and cutting edge volume that brings together a great range of knowledge on propulsion technology, a multi-disciplinary and international subject. The book comprises three main sections covering hydrodynamics; materials and mechanical considerations; and design, operation and performance. The discussion relates theory to practical problems of design, analysis and operational economy, and is supported by extensive design information, operational detail and tabulated data. Fully updated and revised to cover the latest advances in the field, the new edition now also includes four new chapters on azimuthing and podded propulsors, propeller-rudder interaction, high-speed propellers, and propeller-ice interaction.·The most complete book available on marine propellers, fully updated and revised, with four new chapters on azimuthing and podded propulsors, propeller-rudder interaction, high-speed propellers, and propeller-ice interaction·A valuable reference for marine engineers and naval architects gathering together the subject of propulsion technology, in both theory and practice, over the last forty years ·Written by a leading expert on propeller technology, essential for students of propulsion and hydrodynamics, complete with online worked examples
Download or read book A Computer Program for the Preliminary Design of Contrarotating Propellers written by and published by . This book was released on 1975 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents a new computer program that can be used to design and predict the performance of contrarotating propellers. The new propeller utilizes the latest numerical computation techniques developed for the design of contrarotating propellers. The hydrodynamic pitch angle distribution is specified as input and the design calculations are made using Lerb's moderately loaded single screw lifting line propeller theory. The propeller interaction effects (the most important new feature of the design procedure) are obtained using Kerwin's field point velocity program developed using finite bladed lifting surface theory. An analysis of results obtained for a sample set of contrarotating propellers, designed using the new method presented, show that different design and performance predictions are obtained for the aft propellers when results are compared to those calculated using the old method. Calculations made using the new design method are considered more accurate due to the improved method of determining the propeller interaction effects. A FORTRAN listing of the new propeller, developed to run on the computer at the David W. Taylor Naval Ship Research and Development Center (DTNSRDC) is presented as well as input and output obtained for a sample set of contrarotating propeller designs.
Download or read book A Contrarotating Propeller Design for a High Speed Patrol Boat with Pod Propulsion written by Benjamin Y.-H. Chen and published by . This book was released on 1995 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: A contrarotating (CR) propeller design with a tractor pod for a high speed patrol boat is addressed. In the current arrangement, a CR propeller is placed at the forward end of a pod which is aligned with the local inflow. The powering and cavitation experiments show the performance prediction agree well with measurements. Compared to the existing controllable pitch propeller with shaft and struct configureation, the pod-mounted CR propeller show a 28% reduction in power consumption at design speed with a 7 know improvement in cavitation inception speed. At full power, a larger pod is required, which will reduce the gain in power consumption.
Download or read book The Design and Construction of a Test Rig for Investigating Counter rotating Propellers Under Static Conditions written by Charles Vincent Galli and published by . This book was released on 1950 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advanced Turboprop Project written by Roy D. Hager and published by . This book was released on 1988 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Contra rotating Propellers written by H. Lindgren and published by . This book was released on 1967 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design of Propulsors for Underwater Vehicle by Comprehensive Design Method written by Kyungjung Cha and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive method which designs the propeller blades with the maximum efficiency to move a given underwater vehicle at a specified speed is introduced. A previously developed nonlinear optimization algorithm which defines the blade shape by 4×4 B-spline polygon is applied for a target propeller thrust and a given inflow. The propeller performance is evaluated by a vortex-lattice method (VLM) within the optimization scheme. The interaction of the propeller with hull (and duct) is accounted for by coupling the VLM with a Reynolds-Averaged Navier-Stokes (RANS) solver, in order to determine the hull resistance, the propeller thrust, and the propeller inflow. The optimization method as well as the propeller/hull interaction method continue until the propeller thrust and the hull resistance equal each other. The method is applied to design various open, ducted, and contra-rotating propellers for a given underwater vehicle. Several combinations of propeller size and propeller RPM are studied. Additional pressure constraints, such as the minimum pressure constraint and the pressure difference constraint, are imposed for some cases. The effect of propeller diameter and propeller rotational speed on the resulting propeller performance and on the required power are explored, providing proof of concept for the presented method as well as guidance to the propeller designer
Download or read book Proceedings of the 3rd Annual International Conference on Material Machines and Methods for Sustainable Development MMMS2022 written by Banh Tien Long and published by Springer Nature. This book was released on with total page 583 pages. Available in PDF, EPUB and Kindle. Book excerpt:
