Flow Study on a Ducted Azimuth Thruster
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Numerical Study of the Hydrodynamic Characteristics Comparison Between a Ducted Propeller and a Rim-Driven Thruster
applied sciences Article Numerical Study of the Hydrodynamic Characteristics Comparison between a Ducted Propeller and a Rim-Driven Thruster Bao Liu and Maarten Vanierschot * Department of Mechanical Engineering, Group T Leuven Campus, KU Leuven, B-3000 Leuven, Belgium; [email protected] * Correspondence: [email protected] Abstract: The Rim-Driven Thruster (RDT) is an extraordinary innovation in marine propulsion applications. The structure of an RDT resembles a Ducted Propeller (DP), as both contain several propeller blades and a duct shroud. However, unlike the DP, there is no tip clearance in the RDT as the propeller is directly connected to the rim. Instead, a gap clearance exists in the RDT between the rim and the duct. The distinctive difference in structure between the DP and the RDT causes significant discrepancy in the performance and flow features. The present work compares the hydrodynamic performance of a DP and an RDT by means of Computational Fluid Dynamics (CFD). Reynolds-Averaged Navier–Stokes (RANS) equations are solved in combination with an SST k-w turbulence model. Validation and verification of the CFD model is conducted to ensure the numerical accuracy. Steady-state simulations are carried out for a wide range of advance coefficients with the Moving Reference Frame (MRF) approach. The results show that the gap flow in the RDT plays an important role in affecting the performance. Compared to the DP, the RDT produces less thrust on the propeller and duct, and, because of the existence of the rim, the overall efficiency of the RDT is Citation: Liu, B.; Vanierschot, M. Numerical Study of the significantly lower than the one of the ducted propeller. -
GATE RUDDER® PERFORMANCE Noriyuki Sasaki, University of Strathclyde, UK Sadatomo Kuribayashi, Kuribayashi Steam Co. Ltd., Japan
GATE RUDDER® PERFORMANCE Noriyuki Sasaki, University of Strathclyde, UK Sadatomo Kuribayashi, Kuribayashi Steam Co. Ltd., Japan Masahiko Fukazawa, Kamome Propeller Co. Ltd., Japan Mehmet Atlar, University of Strathclyde, UK The world first gate rudder was installed on a 2400 DWT container ship “Shigenobu“ at the end of 2017, and the vessel is showing her extraordinary superior performance for not only trial conditions but also service conditions. Shigenobu has a sistership “Sakura” built in 2016, and the design is exactly the same except the gate rudder system. Two vessels were built by Yamanaka shipyard and have been operated by Imoto line. Both companies are the leader company for the market of coaster shipbuilding and shipping respectively. It was very lucky for the Authors that Imoto line decided to operate two vessels in the same navigation route on the same day. Addition to these operation conditions, Imoto line has swapped the captain and the chief engineer of Sakura for Shigenobu when Shigenbu was delivered. This has provided an opportunity to share the comparative experiences of the vessel crew with both ships as reported in this paper. The paper presents an investigation on the performance of the gate rudder system based on the sea trial data and navigation data which have been collected by the same performance monitoring system “e-navigation” installed on the two vessels. The remarkable difference between two vessels is being investigated using CFD methods at several places such as Istanbul Technical University (ITU) and Kamome Propeller. In addition to the above Shigenobu data, two scaled model test data of Japanese coastal cargo ship are introduced in the paper to explain the scale effect issue of the gate rudder system 1. -
7.5-02-03-02.1, Revi- Benchmark Data Are Collected and Described Sion 01
ITTC – Recommended 7.5-02 -03-02.1 Procedures and Guidelines Page 1 of 10 Testing and Extrapolation Methods Effective Date Revision Propulsion, Propulsor 2008 02 Open Water Test Table of Contents 3.3.6 Temperature ................................. 7 Open Water Tests........................................... 2 3.4 Calibrations ....................................... 7 1. PURPOSE OF PROCEDURE ............... 2 3.4.1 General remarks ........................... 7 2. PARAMETERS: ...................................... 2 3.4.2 Propeller dynamometer: ............... 7 3.4.3 Rate of revolutions ....................... 8 2.1 Data Reduction Equations ............... 2 3.4.4 Speed ............................................ 8 2.2 Definition of Variables ..................... 2 3.4.5 Thermometer ................................ 8 3. PROCEDURE .......................................... 3 3.5 Test Procedure and Data Acquisition ................................................... 8 3.1 Model and Installation ..................... 3 3.6 Data Reduction and Analysis........... 9 3.1.1 Model ........................................... 3 3.7 Documentation .................................. 9 3.1.2 Installation .................................... 3 3.2 Measurement Systems ...................... 5 4. VALIDATION ......................................... 9 3.3 Instrumentation ................................ 6 4.1 Uncertainty Analysis ........................ 9 3.3.1 General remarks ........................... 6 4.2 Benchmark Tests ........................... -
A Comparison of Pumpjets and Propellers for Non-Nuclear Submarine Propulsion
A comparison of pumpjets and propellers for non-nuclear submarine propulsion Aidan Morrison January 2018 Trendlock Consulting Contents 1 Introduction 3 2 Executive Summary 5 3 Speed and Drag - Why very slow is very very (very)2 economical 9 3.1 The physical relationship . .9 3.2 Practical implications for submarines . 10 4 The difference between nuclear and conventional propulsion 12 4.1 Power and Energy . 12 4.2 Xenon poisoning and low power limitations . 12 4.3 Recent Commentary . 14 5 Basics of Ducted Propellers and Pumpjets 16 5.1 Propellers . 16 5.1.1 Pitch . 16 5.1.2 Pitch and the Advance Ratio . 18 5.2 Ducted Propellers . 20 5.2.1 The Accelerating Duct . 21 5.2.2 The Decelerating Duct or Pumpjet . 22 5.2.3 Waterjets . 24 5.3 Pump Types . 25 6 Constraints on the efficiency of pumpjets at low speed 28 6.1 Recent Commentary . 28 6.2 Modern literature and results . 28 6.3 A simple theoretical explanation . 31 6.4 Trade-offs and Limitations on Improvements . 34 6.5 The impact of duct loss on an ideal propeller . 36 6.6 An assessment of scope for improving the efficiency of a pumpjet at low speeds . 41 6.6.1 Increase mass-flow by widening area of intake . 42 6.6.2 Reduce degree of diffusion (i.e. switch to accelerating duct) to reduce negative thrust from duct.................................................. 45 6.6.3 Reduce shroud length to decrease drag on duct . 46 6.6.4 Summary remarks on potential for redesign of pumpjet for low-speed conditions . -
Submarine Pumpjets
UNCLASSIFIED REPORT FOR THE SENATE ECONOMIC REFERENCES COMMITTEE SUBMARINE PROPULSORS DEPARTMENT OF DEFENCE INTRODUCTION 1. At the Senate Economics References Committee (“Committee”) hearing of 7 June 2018, the Department of Defence was requested to provide an evaluation of views of Mr Aiden Morrison on submarine propulsors1, which he has expressed through a number of reports and in testimony to the Committee. The Department welcomes these contributing views and the opportunity to comment on such reports to aid a broader understanding of issues related to defence technology and the development of Australia’s Future Submarine capability. 2. The Department has examined Mr Morrison’s report with the support of experts in Defence Science and Technology, and has consulted with external experts in pumpjet technology. 3. In summary, Mr Morrison’s conclusions are based on analysis which does not fully address essential design parameters and considerations important to evaluating propulsor performance on submarines. Mr Morrison has also used surface ship data in part as evidence, which he has extrapolated to the submarine environment to form his conclusions. 4. In his testimony to the Committee, Mr Morrison stated, ‘The key conclusions that I arrived at were that pump jets have a far lower efficiency than propellers at a low speed of travel in contrast to high speeds, where jets tend to become more efficient.’ 5. The Department maintains the view that this conclusion is incorrect in the case of submerged submarine for the following reasons: a. The efficiency of a propulsor, whether it is a pumpjet or propeller, for a submerged submarine is related to the total submerged resistance and is essentially constant over speed, noting the submerged resistance of a submarine is dependent on the total skin friction and the shape of the submarine. -
Cavitation and Induced Excitation Force of Ice-Class Propeller Blocked by Ice
Journal of Marine Science and Engineering Article Cavitation and Induced Excitation Force of Ice-Class Propeller Blocked by Ice Pei Xu 1, Chao Wang 1 , Liyu Ye 1,*, Chunyu Guo 1, Weipeng Xiong 1 and Shen Wu 2 1 College of Shipbuilding Engineering, Harbin Engineering University, Harbin 150001, China; [email protected] (P.X.); [email protected] (C.W.); [email protected] (C.G.); [email protected] (W.X.) 2 National Key Laboratory on Ship Vibration and Noise, China Ship Scientific Research Center, Wuxi 214082, China; [email protected] * Correspondence: [email protected]; Tel.: +86-18-845-596-576 Abstract: The presence of broken ice in the flow field around a propeller causes severe blade erosion, shafting, and hull vibration. This study investigates the performance of the propeller of a ship sailing in the polar regions under the propeller–ice non-contact condition. To this end, we construct a test platform for the propeller-induced excitation force due to ice blockage in a large circulating water channel. The hydrodynamic load of the propeller, and the cavitation and propeller- induced fluctuating pressure, were measured and observed by varying the cavitation number and ice–propeller axial distance under atmospheric pressure and decompression conditions. The results show that the fluctuation range of the blade load increases with a decrease in cavitation number and ice–propeller axial distance. The decrease in the cavitation number leads to broadband characteristics in the frequency-domain curves of the propeller thrust coefficient and blade-bearing force. Under the Citation: Xu, P.; Wang, C.; Ye, L.; combined effects of ice blockage and proximity, propeller suction, the circumfluence zone around Guo, C.; Xiong, W.; Wu, S. -
Marine Products and Systems
MARINE PRODUCTS AND SYSTEMS kongsberg.com Our technologies, products and systems are continually improving. For the latest information please go to www.km.kongsberg.com All information is subject to change without notice. Content Introduction 03 Ship design 05 Propulsion systems 25 Diesel and gas engines 35 PROPULSORS • Azimuth thrusters 49 • Propellers 61 • Waterjets 67 • Tunnel thrusters 75 • Promas 81 • Podded propulsors 87 Reduction gears 97 STABILISATION AND MANOEUVRING • Stabilisers 101 • Steering gear 109 • Rudders 117 Deck machinery solutions 123 ELECTRICAL POWER AND AUTOMATION SYSTEMS • Electrical power systems 145 • Automation systems 163 Global service and support 171 02 We are determined to provide our customers with innovative and dependable marine systems that ensure optimal operation at sea. By utilising and integrating our technology, experience and competencies within design, deck machinery, propulsion, positioning, detection and automation we aim to give our customers the full picture - shaping the future of the maritime industry. Our industry expertise covers a fleet of more than 30,000 vessels. While we are the largest marine technology specialist organisation in the world, with the most extensive product and knowledge base, our focus continues to be on customers and the environment. Only by listening to you and predicting industry needs can we enable the transformation needed to put safety and sustainability first, while continuing to generate value for all stakeholders. The Full Picture consists of our product portfolios, world class support networks and more than 3500 expert staff located in 34 countries across the globe. We are shaping the maritime future with leading edge operational technology, solutions for big data and digital transformation, new electric and hybrid power systems and truly game-changing developments in remote operations and Maritime Autonomous Surface Ships (MASS). -
Marine Propulsion Or Steering
B63H MARINE PROPULSION OR STEERING ([N: arrangement of propulsion or steering means on amphibious vehicles B60F3/0007;] propulsion of air-cushion vehicles B60V1/14; peculiar to submarines, other than nuclear propulsion, B63G; peculiar to torpedoes F42B19/00 ) Definition statement This subclass/group covers: Propulsive elements directly acting on water, e.g.: • Paddle wheels. • Voith-Schneider propellers. • Propellers and propeller blades. • Endless-track type propulsive elements. • Fishtail-type propulsive elements. • Propeller-blade pitch changing. • Arrangements of propulsive elements directly acting on water. Effecting propulsion by jets, e.g. using reaction principle. • Jet propulsion using ambient water as propulsive medium. • Jet propulsion using steam or gas as propulsive medium. • Arrangements of propulsive elements directly acting on air. Propulsive devices directly acted on by wind, e.g.: • Sails • Magnus-rotors • Arrangements of propulsive devices directly acted on by wind • Wind motors driving water-engaging propulsive elements. Effecting propulsion by use of vessel-mounted driving mechanisms co#operating with anchored chains or the like. Effecting propulsion by muscle power Effecting propulsion of vessels, not otherwise provided for, e.g. 1 • Using energy from ambient water. • By direct engagement of the ground. Outboard propulsion units and Z-drives. Use of propulsion power plant or units on vessels: • Use of e.g. steam, internal combustion, electric or nuclear power plants • Arrangements of power plant control exterior of the engine room • Mounting of propulsion plant or unit • Arrangements of propulsion-unit exhaust uptakes • Apparatus or methods specially adapted for use on marine vessels, for handling power plant or unit liquids, e.g. lubricants, coolants, fuels or the like Transmitting power from propulsion power plant to propulsive elements, e.g. -
Simulation of Unsteady Interaction Forces on a Ducted Propeller with Pre-Swirl Stators
Third International Symposium on Marine Propulsors smp’13, Launceston, Tasmania, Australia, May 2013 Simulation of Unsteady Interaction Forces on a Ducted Propeller with Pre-swirl Stators Zhi-Qiang Rao, Wei Li, Chen-Jun Yang State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University, Shanghai, China ABSTRACT induced by propulsor, the discussion on the frequency The frequency characteristics of unsteady forces arising characteristics is inevitable. from the hydrodynamic interaction between the rotor and The research on this kind of propulsor is relatively less stators for a ducted propeller with pre-swirl stators is than on ordinary propulsors owing to the complicated analyzed theoretically. It is shown that the axial force and flow phenomenon around the propulsor. A potential-based moment fluctuate at frequencies equal to nZRN on panel method for the duct coupled with the lifting surface condition that nZR=kZS, where k and n are both positive method for the rotor and stators were presented by Hughes integers, ZR and ZS are the rotor and stator blade numbers & Kinnas (1991), Wang & Yang (1993), and Wang & Liu respectively, and N is the shaft frequency of the rotor. The (2007). In these papers the steady performance was lateral forces and moments also fluctuate at multiples of predicted. The unsteady thrust and torque were presented the rotor's blade frequency, but on condition that by Wang & Liu (2007), however the frequency and nZR=kZS±1. Therefore, the axial and lateral forces do not amplitude characteristics were not analyzed nor discussed. fluctuate at the same frequency, and in many cases the During the past forty years, computational fluid dynamics lowest fluctuation frequency of the lateral forces are much (CFD) has been developing rapidly and finding more and lower than that of the axial force. -
Ducted Fan Aerodynamics and Modeling, with Applications of Steady and Synthetic Jet Flow Control
Ducted Fan Aerodynamics and Modeling, with Applications of Steady and Synthetic Jet Flow Control Osgar John Ohanian III Dissertation submitted to the faculty of the Virginia Polytechnic Institute and State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy In Mechanical Engineering Daniel J. Inman, Committee Chair Kevin B. Kochersberger Andrew J. Kurdila William H. Mason Sam B. Wilson May 4th, 2011 Blacksburg, VA Keywords: ducted fan, shrouded propeller, synthetic jets, flow control, aerodynamic modeling, non-dimensional, unmanned aerial vehicle, micro air vehicle Copyright 2011, Osgar John Ohanian III Ducted Fan Aerodynamics and Modeling, with Applications of Steady and Synthetic Jet Flow Control Osgar John Ohanian III ABSTRACT Ducted fan vehicles possess a superior ability to maximize payload capacity while minimizing vehicle size. Their ability to both hover and fly at high speed is a key advantage for information-gathering missions, particularly when close proximity to a target is essential. However, the ducted fans aerodynamic characteristics pose difficulties for stable vehicle flight and therefore require complex control algorithms. In particular, they exhibit a large nose-up pitching moment during wind gusts and when transitioning from hover to forward flight. Understanding ducted fan aerodynamic behavior and how it can be altered through flow control techniques are the two prime objectives of this work. This dissertation provides a new paradigm for modeling the ducted fans nonlinear behavior and new methods for changing the duct aerodynamics using active flow control. Steady and piezoelectric synthetic jet blowing are employed in the flow control concepts and are compared. The new aerodynamic model captures the nonlinear characteristics of the force, moment, and power data for a ducted fan, while representing these terms in a set of simple equations. -
Review on Ducted Fans for Compound Rotorcraft
\ Zhang, T. and Barakos, G. N. (2020) Review on ducted fans for compound rotorcraft. Aeronautical Journal, 124, pp. 941-974. (doi: 10.1017/aer.2019.164) The material cannot be used for any other purpose without further permission of the publisher and is for private use only. There may be differences between this version and the published version. You are advised to consult the publisher’s version if you wish to cite from it. http://eprints.gla.ac.uk/206001/ Deposited on 16 December 2019 Enlighten – Research publications by members of the University of Glasgow http://eprints.gla.ac.uk Review on Ducted Fans for Compound Rotorcraft Tao Zhang 1 and George N. Barakos 2 CFD Laboratory, School of Engineering, University of Glasgow, G12 8QQ, Scotland, UK www.gla.ac.uk/cfd Abstract This paper presents a survey of published works on ducted fans for aeronautical ap- plications. Early and recent experiments on full- or model-scale ducted fans are reviewed. Theoretical studies, lower-order simulations and high-fidelity CFD simulations are also summarised. Test matrices of several experimental and numerical studies are compiled and discussed. The paper closes with a summary of challenges for future ducted fan research. Nomenclature A Propeller disk area Ae Duct exit area AoA Duct angle of attack cduct Duct profile chord length Din Duct inner diameter FoM Figure of Merit Ma Mach number Pdf Ducted fan power Pop Open propeller power Re Reynolds number (Re = V∞cduct/ν∞) RPM Revolutions Per Minute Tdf Duct fan thrust 1PhD Candidate - [email protected] -
Thrust Estimation and Control of Marine Propellers in Four- Quadrant Operations
Luca Pivano Thrust Estimation and Control of Marine Propellers in Four- Quadrant Operations Thesis for the degree of philosophiae doctor Trondheim, April 2008 Norwegian University of Science and Technology Faculty of Information Technology, Mathematics, and Electrical Engineering Department of Engineering Cybernetics NTNU Norwegian University of Science and Technology Thesis for the degree of philosophiae doctor Faculty of Information Technology, Mathematics, and Electrical Engineering Department of Engineering Cybernetics ©Luca Pivano ISBN 978-82-471-6258-3 (printed ver.) ISBN 978-82-471-6261-3 (electronic ver.) ISSN 1503-8181 ITK report 2008:3-W Theses at NTNU, 2008:20 Printed by Tapir Uttrykk Summary Speed and position control systems for marine vehicles have been subject to an increased focus with respect to performance and safety. An example is represented by drilling operations performed with semi submersible rigs where the control of position and heading requires high accuracy. Drift- ing from the well position could cause severe damage to equipment and environment. Also, the use of underwater vehicles for deep ocean survey, exploration, bathymetric mapping and reconnaissance missions, has be- come lately more widespread. The employment of such vehicles in complex missions requires high precision and maneuverability. This thesis focuses on thrust estimation and control of marine pro- pellers with particular attention to four-quadrant operations, in which the propeller shaft speed and the propeller in‡ow velocity (advance speed) as- sume values in the whole plane. In the overall control system, propellers play a fundamental role since they are the main force producing devices. The primary objective of the thruster controller is to obtain the desired thrust from the propeller regardless the environmental state.