DOCSLIB.ORG

Ducted Fan Aerodynamics and Modeling, with Applications of Steady and Synthetic Jet Flow Control

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
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. The model attains excellent agreement with current and legacy experimental data using twelve non- dimensional constants. Synthetic jet actuators (SJA) have potential for use in flow control applications in UAVs with limited size, weight, and power budgets. Piezoelectric SJAs for a ducted fan vehicle were developed through two rounds of experimental designs. The final SJA design attained peak jet velocities in the range of 225 ft/sec (69 m/s) for a 0.03 x 0.80 rectangular slot. To reduce the magnitude of the nose-up pitching moment in cross-winds, two flow control concepts were explored: flow separation control at the duct lip, and flow turning at the duct trailing edge using a Coandă surface. Both concepts were experimentally proven to be successful. Synthetic jets and steady jets were capable of modifying the ducted fan flow to reduce pitching moment, but some cases required high values of steady blowing to create significant responses. Triggering leading edge separation on the duct lip was one application where synthetic jets showed comparable performance to steady jets operating at a blowing coefficient an order of magnitude higher. Acknowledgements Trust in the Lord with all your heart, and lean not on your own understanding, in all you ways acknowledge Him, and He shall direct your paths. Proverbs 3:5-6 Delight yourself in the Lord, and He will give you the desires of your heart. Psalm 37:4 I am the vine, you are the branches. He who abides in Me, and I in him, bears much fruit; for without Me you can do nothing. -Jesus speaking in John 15:5 First and foremost, I would like to thank my loving Creator for making me a curious being who loves to explore His creation and for giving me the opportunity to write this dissertation. Without Him, I can do nothing. Next, I would like to thank my supportive and loving wife, Robin, who has made this arduous journey much more pleasant. Her love and helpful spirit have motivated me to achievements beyond my own expectations. To my children, Ansley, Caleb, Jacob, and Charlotte, thank you for brightening my days when I was uncertain whether I would ever finish, and for your patience when Daddy was busy. I hope to pass on to you my life-long love of learning and exploration of Gods creation. I would like to thank my dad, John, for being a role model in godliness, work ethic, integrity, and care for others. I cant imagine what I would be without your loving guidance over the course of my life. I would like to thank my mom, Mary, for her spontaneous nature, love of people, and appreciation for education. Mom, I love you, and I couldnt have done this without you. For my stepmom, Kim, I wish I could have finished this while you were here, but I know you are cheering me on from heaven. I am rejoicing for your freedom from suffering, and look forward to joining you at the celebration banquet table some day. I would like to thank my advisor, Dr. Dan Inman, for accepting this unconventional Ph.D. student, never losing faith that I would finish, and iii encouraging me all along the way. I have learned more from you than you probably realize. I would like to thank my committee, which includes Dr. Kevin Kochersberger, Dr. Bill Mason, Dr. Andrew Kurdila, and the Right Reverend of the STOVL Faithful, Sam Wilson. Your time and service is sincerely appreciated, and your insights and input to my work have been valuable. To all of my colleagues at AVID LLC, I owe great thanks for their encouragement, helpful collaboration, and creative ideas. Specifically I would like to thank Paul Gelhausen for allowing me the opportunity to pursue a PhD while working full time and supporting me along the way. Now I can get back to work. I would also like to thank all the team members on my SBIR project that contributed to the larger research effort in one way or another. From AVID: Etan Karni, for helping in almost every aspect of the project; Kelly Londenberg, for his CFD work; Adam Entsminger, for his design insights; Chris Hickling, for all the CAD work; Brandon Stiltner, for help with simulations; Chris Olien, for help with experiments; Ignacio Guerrero, for help in vehicle sizing and design; Andy Turnbull, for help with fan designs; Dr. Andy Ko for his general insights; Scott Helsing, for his program management input; and Seth Taylor, for his aerodynamic modeling in Phase I. From Virginia Tech: Onur Bilgen, who pioneered MFC morphing control surfaces on our project; and Bill Otjens and Dr. William Devenport for their support at the Virginia Tech Stability Wind Tunnel. From Techsburg, Inc: Jon Fleming, Sarah Tweedie, and Matt Langford for their help fabricating the test model and executing the wind tunnel tests. From Honeywell Labs: Dale Enns and Eric Euteneuer, for their help in simulation and flight control insights. And from the Air Force Research Lab: James Davis, and Chris Perry, the Air Force program managers on my project. I would like to acknowledge and thank the Air Force Research Lab/Munitions Directorate at Eglin AFB and the Air Force Office of Sponsored Research for funding this research. iv Table of Contents ABSTRACT .................................................................................................................................... ii Acknowledgements ........................................................................................................................ iii Table of Contents ............................................................................................................................ v List of Figures ................................................................................................................................ vi List of Tables ................................................................................................................................. ix Chapter 1 Introduction and Motivation ...................................................................................... 1 1.1 Coordinate System ............................................................................................................. 3 1.2 Comparison to Other UAV Configurations ....................................................................... 5 1.3 Research Objectives ......................................................................................................... 11 1.4 Flow Control Concepts .................................................................................................... 12 Chapter 2 Literature Review and Background .......................................................................... 16 2.1 Ducted Fan Aerodynamics ............................................................................................... 16 2.1.1 Fundamental Aerodynamics ..................................................................................... 17 2.1.2 Ducted Fan Aerodynamic Modeling ......................................................................... 19 2.1.3 Ducted Fan Vehicle Design ...................................................................................... 21 2.1.4 Ducted Fan Flight Control ........................................................................................ 23 2.2 Synthetic Jets ................................................................................................................... 25 2.2.1 Synthetic Jet Fluid Mechanics .................................................................................. 26 2.2.2 Synthetic Jet Modeling ............................................................................................. 27 2.2.3 Synthetic Jet Actuator Design ..................................................................................
Load more

Recommended publications
  • Open LMM MS Thesis.Pdf
    The Pennsylvania State University The Graduate School Department of Aerospace Engineering AERODYNAMIC EXPERIMENTS ON A DUCTED FAN IN HOVER AND EDGEWISE FLIGHT A Thesis in Aerospace Engineering by Leighton Montgomery Myers 2009 Leighton Montgomery Myers Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science December 2009 The thesis of Leighton Montgomery Myers was reviewed and approved* by the following: Dennis K. McLaughlin Professor of Aerospace Engineering Thesis Advisor Joseph F. Horn Associate Professor of Aerospace Engineering Michael Krane Research Associate PSU Applied Research Laboratory George A. Lesieutre Professor of Aerospace Engineering Head of the Department of Aerospace Engineering *Signatures are on file in the Graduate School ii ABSTRACT Ducted fans and ducted rotors have been integrated into a wide range of aerospace vehicles, including manned and unmanned systems. Ducted fans offer many potential advantages, the most important of which is an ability to operate safely in confined spaces. There is also the potential for lower environmental noise and increased safety in shipboard operations (due to the shrouded blades). However, ducted lift fans in edgewise forward flight are extremely complicated devices and are not well understood. Future development of air vehicles that use ducted fans for lift (and some portion of forward propulsion) is currently handicapped by some fundamental aerodynamic issues. These issues influence the thrust performance, the unsteadiness leading to vehicle instabilities and control, and aerodynamically generated noise. Less than optimum performance in any of these areas can result in the vehicle using the ducted fan remaining a research idea instead of one in active service.
    [Show full text]
  • Flow Study on a Ducted Azimuth Thruster
    Flow Study on a Ducted Azimuth Thruster VII International Conference on Computational Methods in Marine Engineering MARINE 2017 M. Visonneau, P. Queutey and D. Le Touzé (Eds) FLOW STUDY ON A DUCTED AZIMUTH THRUSTER PATRICK SCHILLER*, KEQI WANG* AND MOUSTAFA ABDEL-MAKSOUD* * Institute for Fluid Dynamics and Ship Theory (M-8), Hamburg University of Technology, Am Schwarzenberg-Campus 4, 21073 Hamburg, Germany e-mail: [email protected], url: http://www.tuhh.de/fds Key words: Computational Methods, Marine Engineering, Ducted Azimuth Thruster Abstract. This paper presents the results of the numerical validation and verification studies on an azimuth thruster. The numerical investigations include a grid study as well as an analysis of the simulation results obtained by different isotropic an anisotropic turbulence models, such as k-omega, SST, SAS-SST, BSL-EARSM and DES. The numerical simulation results of selected flow conditions are compared with experimental data. To investigate scale effects on the open water results numerical computations are carried out for a thruster in full- and model scale and the calculated thrust and torque coefficients are compared with model scale simulations and measurements. 1 INTRODUCTION Azimuth Thrusters may experience considerable high dynamic loads due to operation in extreme off-design conditions. The flow on Azimuth Thrusters is highly unsteady due to large cavitation and separation areas, which may take place at strong oblique flow conditions. These strong oblique flows can be caused by high steering angles of the azimuth thruster, due to high drift angle of the ship or strong ocean currents. This may lead to high continuous changes in the amplitudes of the forces and moments and to flow separation on propeller blades and other components of the propulsion system, such as the shaft, the connecting struts between the nozzle and propeller hub or to the gondola.
    [Show full text]
  • United States Patent (19) 11 Patent Number: 4,996,839 Wilkinson Et Al
    United States Patent (19) 11 Patent Number: 4,996,839 Wilkinson et al. 45 Date of Patent: Mar. 5, 1991 54 TURBOCHARGED COMPOUND CYCLE FOREIGN PATENT DOCUMENTS DUCTED FAN ENGINE SYSTEM 3330315 3/1985 Fed. Rep. of Germany ........ 60/624 75) Inventors: Ronald Wilkinson; Ralph Benway, 916985 9/1946 France .......................... both of Mobile, Ala. 437018 10/1935 United Kingdom .................. 60/612 Primary Examiner-Michael Koczo 73 Assignee: Teledyne Industries, Inc., Los Attorney, Agent, or Firm-Gifford, Groh, Sprinkle, Angeles, Calif. Patmore and Anderson (21) Appl. No.: 329,661 (57) ABSTRACT A turbocharged, compounded cycle ducted fan engine (22 Filed: Mar. 29, 1989 system includes a conventional internal combustion engine drivingly connected to a fan enclosed in a duct. Related U.S. Application Data The fan provides propulsive thrust by accelerating air 63 Divisional Ser. No. 17,825, Feb. 24, 1987, Pat. No. through the duct and out an exhaust nozzle. A turbo 4,815,282. charger is disposed in the duct and receives a portion of the air compressed by the fan. The turbocharger com 51) Int. Cli................................................ F02K 5/02 pressor further pressurizes the air and directs it to the 52 U.S. Cl. ............ ... 60/247; 60/263; internal combustion engine where it is burned and exits 60/269; 60/605 as exhaust gas to drive the turbine. A power turbine also 58) Field of Search ................. 60/598, 605, 606, 612, driven by exhaust gas is also drivingly connected 60/624, 226.1, 247, 263, 269 through the engine to the fan to provide additional power. The size and weight of the turbocharger are (56) References Cited reduced since the compressor's work is partially U.S.
    [Show full text]
  • 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.
    [Show full text]
  • 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.
    [Show full text]
  • Configuration Design and Optimization of Ducted Fan Using Parameter Based Design
    DOI: 10.13009/EUCASS2017-373 7TH EUROPEAN CONFERENCE FOR AERONAUTICS AND SPACE SCIENCES (EUCASS) Configuration Design and Optimization of Ducted Fan Using Parameter Based Design Yun Ki Jung*, Kwon-Su Jeon, Cheol-Kyun Choi, Tyan Maxim, Sangho Kim, and Jae-Woo Lee ** * Konkuk University Seoul, Republic of Korea ** Konkuk University Seoul, Republic of Korea Abstract In this study, ducted fan configuration design and optimization program is developed. With this program, configuration design and optimization of ducted fan which improves hovering performance is performed. First, the configuration parameters that have effects on performance of ducted fan are selected. Based on these parameters, baseline of ducted is constructed by the program. Optimization problem is formulated based on baseline configuration. Ducted Fan Design Code is used to generate design points. With the baseline configuration, optimization is performed. After optimization, optimum configuration is obtained, and 3D modelling of optimized ducted fan is generated automatically by optimum configuration parameters. 1. Introduction Lift fan aircraft is the one of compound aircraft which is combining conventional and vertical take-off & landing (VTOL). Lift fan aircraft has many advantage than conventional type aircraft. First advantage of lift fan is that lift fan aircraft can vertically take-off and land. Second is that ducted fan is adequate to install into wing or fuselage. Third is that runway is not required. Last is that it is faster than existing rotorcraft when it is in cruise state. [1] Chao verifies that the influences of ducted fan’s inlet and exit on its figure of merit and thrust. [2][3] By optimizing configuration of inlet and exit, ducted fan’s performance can be changed.
    [Show full text]
  • Optimization and Analysis of an Elite Electric Propulsion System
    International Journal of Aviation, Aeronautics, and Aerospace Volume 6 Issue 5 Article 5 2019 Optimization and Analysis of an Elite Electric Propulsion System Mehakveer Singh Punjab Engineering College (Deemed to be University)., [email protected] Kapil Yadav [email protected] Satnam Singh [email protected] Vikas Chumber [email protected] Harikrishna Chavhan [email protected] Follow this and additional works at: https://commons.erau.edu/ijaaa Part of the Aeronautical Vehicles Commons, Propulsion and Power Commons, and the Systems Engineering and Multidisciplinary Design Optimization Commons Scholarly Commons Citation Singh, M., Yadav, K., Singh, S., Chumber, V., & Chavhan, H. (2019). Optimization and Analysis of an Elite Electric Propulsion System. International Journal of Aviation, Aeronautics, and Aerospace, 6(5). https://doi.org/10.15394/ijaaa.2019.1419 This Concept Paper is brought to you for free and open access by the Journals at Scholarly Commons. It has been accepted for inclusion in International Journal of Aviation, Aeronautics, and Aerospace by an authorized administrator of Scholarly Commons. For more information, please contact [email protected]. Singh et al.: OPTIMIZATION AND ANALYSIS OF AN ELITE ELECTRIC PROPULSION SYSTEM Introduction This paper is envisioned to serve the general impression of the modern technology of electric-based propulsion, its application, and scope. The aeronautics industries have been challenged to enhance efficiency, reduce noise, emission, and decrease dependency on carbon-based fuel aircraft. The aircraft of the future will be simpler to operate and more capable than today’s combustion engine due to a convergence of technologies, mainly Electric Propulsion (Rezende, Barros, & Perez 2018). An aircraft propulsion technology is mainly depended on the use of petroleum-based internal combustion engines, in the form of either aviation turbine fuel or aviation gasoline.
    [Show full text]
  • 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 ...........................
    [Show full text]
  • 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 .
    [Show full text]
  • 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.
    [Show full text]
  • 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.
    [Show full text]
  • 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).
    [Show full text]