scholarly journals Research on Optimization of Parametric Propeller Based on Anti-Icing Performance and Simulation of Cutting State of Ice Propeller

2021 ◽  
Vol 9 (11) ◽  
pp. 1247
Author(s):  
Yu Lu ◽  
Chunxiao Wu ◽  
Shewen Liu ◽  
Zhuhao Gu ◽  
Wu Shao ◽  
...  
Keyword(s):  
Optimization Design ◽  
International Association ◽  
Equivalent Stress ◽  
Design Procedure ◽  
Optimal Solution ◽  
Open Water ◽  
Hydrodynamic Performance ◽  
Water Efficiency ◽  
Nsga Ii ◽  
Thrust Coefficient

When a ship sails in an ice area, the ice could cause damage to ship hull and the propeller as well as the rudder. In the design process of an ice class propeller, the strength verification of the propeller has always been the focus of the design and research of the ice propeller. Based on the International Association of Classification Societies Unified Requirements for Polar Class (IACS Polar UR), it is required that the maximum torque from the propeller cannot exceed the required value to ensure the safety of the propeller shafting equipment. This paper investigates the hydrodynamic performance of the propeller under the condition of satisfying the propeller’s ice strength. A parametric propeller optimization design procedure was established in which the thrust coefficient and open water efficiency solved by CFD method were selected as the objective function and optimization target, the maximum ice torque was used as the optimization constraint under the condition that the ship’s shafting equipment remains unchanged, the propeller pitch, thickness, and camber at each radial direction were taken as the optimization design variables, and the optimization algorithm of SOBOL and NSGA-II was adopted. The interaction mode of propeller and ice was simulated by the method of explicit dynamics. The equivalent stress and displacement response of the blade during the cutting process of the ice propeller were calculated, monitoring the ice destruction process. The results show that the multi-objective Pareto optimal solution set of thrust coefficient and open water efficiency of the ice class propeller was formed at the design speed while maintain the maximum ice torque not exceeding the original ice torque.

Multi-Objective Optimization Design of Control Devices to Suppress Tall Buildings Vibrations against Earthquake Excitations Using Fuzzy Logic and Genetic Algorithms

2015 ◽  
pp. 787-817
Author(s):  
Saeid Pourzeynali ◽  
Shide Salimi
Keyword(s):  
Genetic Algorithms ◽  
Fuzzy Logic ◽  
Optimization Design ◽  
Base Isolation ◽  
Control Strategies ◽  
Optimal Solution ◽  
Base Shear ◽  
Viscous Dampers ◽  
Nsga Ii ◽  
Isolation Systems

The main objective of this chapter is to find the optimal values of the parameters of the base isolation systems and that of the semi-active viscous dampers using genetic algorithms (GAs) and fuzzy logic in order to simultaneously minimize the buildings' selected responses such as displacement of the top story, base shear, and so on. In this study, performance of base isolation systems, and semi-active viscous dampers are studied separately as different vibration control strategies. In order to simultaneously minimize the objective functions, a fast and elitist non-dominated sorting genetic algorithm (NSGA-II) approach is used to find a set of Pareto-optimal solution. To study the performance of semi-active viscous dampers, the torsional effects exist in the building due to irregularities, and unsymmetrical placement of the dampers is taken into account through 3D modeling of the building.

A 2.5D numerical study on open water hydrodynamic performance of a Voith-Schneider propeller

2019 ◽  
Vol 20 (6) ◽  
pp. 617
Author(s):  
Mohammad Bakhtiari ◽  
Hassan Ghassemi
Keyword(s):  
Numerical Method ◽  
Thrust Force ◽  
Numerical Study ◽  
Open Water ◽  
Hydrodynamic Performance ◽  
Maximum Efficiency ◽  
Water Efficiency ◽  
Blade Thickness ◽  
Unsteady Rans ◽  
Marine Vessels

Marine cycloidal propeller (MCP) is a special type of marine propulsors that provides high maneuverability for marine vessels. In a MCP, the propeller axis of rotation is perpendicular to the direction of thrust force. It consists of a number of lifting blade. Each blade rotates about the propeller axis and simultaneously pitches about its own axis. The magnitude and direction of thrust force can be adjusted by controlling the propeller pitch. Voith-Schneider propeller (VSP) is a low-pitch MCP with pure cycloidal blade motion allowing fast, accurate, and stepless control of thrust magnitude and direction. Generally, low-pitch cycloidal propellers are used in applications with low speed maneuvering requirements, such as tugboats, minesweepers, etc. In this study, a 2.5D numerical method based on unsteady RANS equations with SST k-ω turbulent model was implemented to predict the open water hydrodynamic performance of a VSP for different propeller pitches and blade thicknesses. The numerical method was validated against the experimental data before applying to VSP. The results showed that maximum open water efficiency of a VSP is enhanced by increasing the propeller pitch. Furthermore, the effect of blade thickness on open water efficiency is different at various advance coefficients, so that the maximum efficiency produced by the VSP decreases with increasing blade thickness at different propeller pitches.

Multi-Objective Shape Optimization Design for LNG Cryogenic Helical Corrugated Steel Pipe

2016 ◽  
Author(s):  
Zhixun Yang ◽  
Jun Yan ◽  
Qingzhen Lu ◽  
Jinlong Chen ◽  
Shanghua Wu ◽  
...  
Keyword(s):  
Shape Optimization ◽  
Optimization Design ◽  
Rbf Neural Network ◽  
Optimal Solution ◽  
Steel Pipe ◽  
Structural Deformation ◽  
Design Parameters ◽  
Operation Condition ◽  
Nsga Ii ◽  
Multi Objective

The flexible cryogenic hose has been a favored alternative for offshore liquefied natural gas (LNG) exploitation recently, of which helical corrugated steel pipe is the crucial component with C shaped corrugation. Parametric finite-element models of LNG cryogenic helical corrugated pipe are presented based on 3D shell element in this paper. Taking account of nonlinearity such as cryogenic material and large geometric structural deformation, mechanical behavior characteristics results are obtained under axial tensional, bending and inner pressure loads. Meanwhile, the design parameters are determined for the shape optimization of structures of the flexible cryogenic hose through sectional dimension analysis, and sensitivity analysis is performed with changing geometric parameters. A multi-objective optimization with the object of minimizing stiffness and strength stress is formulated based on operation condition. Full factorial experiment and radial basis function (RBF) neural network are applied to establish the approximated model for the analysis of the structure. The Pareto optimal solution set and value range of parameters are obtained through NSGA-II GA algorithm under manufacturing and stiffness constraints. It provides a feasible optimal approach for the structural design of LNG cryogenic corrugated hose.

Multi-Objective Optimization Design of Control Devices to Suppress Tall Buildings Vibrations against Earthquake Excitations Using Fuzzy Logic and Genetic Algorithms

2013 ◽  
pp. 180-215
Author(s):  
Saeid Pourzeynali ◽  
Shide Salimi
Keyword(s):  
Genetic Algorithms ◽  
Fuzzy Logic ◽  
Optimization Design ◽  
Base Isolation ◽  
Control Strategies ◽  
Optimal Solution ◽  
Base Shear ◽  
Viscous Dampers ◽  
Nsga Ii ◽  
Isolation Systems

The main objective of this chapter is to find the optimal values of the parameters of the base isolation systems and that of the semi-active viscous dampers using genetic algorithms (GAs) and fuzzy logic in order to simultaneously minimize the buildings’ selected responses such as displacement of the top story, base shear, and so on. In this study, performance of base isolation systems, and semi-active viscous dampers are studied separately as different vibration control strategies. In order to simultaneously minimize the objective functions, a fast and elitist non-dominated sorting genetic algorithm (NSGA-II) approach is used to find a set of Pareto-optimal solution. To study the performance of semi-active viscous dampers, the torsional effects exist in the building due to irregularities, and unsymmetrical placement of the dampers is taken into account through 3D modeling of the building.

ANALISA ENGINE PROPELLER MATCHING (EPM) PADA KAPAL RESCUE BOAT KARENA PERUBAHAN TAHAP POWERING PROCESS

2020 ◽  
Vol 21 (1) ◽  
pp. 49-55
Author(s):  
Muhammad Sawal Baital ◽  
Ari Bawono Putranto ◽  
Bambang Sri Waluyo
Keyword(s):  
Theoretical Approach ◽  
Open Water ◽  
Data Series ◽  
Water Efficiency ◽  
Thrust Coefficient ◽  
Process Stage ◽  
Propeller Design ◽  
Main Engine ◽  
Propeller Thrust ◽  
Fixed Pitch

This study is to investigate compatibility between installed main engine in ship with propeller design using theoretical approach and data series. A triple screw rescue boat conducted hard chain hull was used for study and analyze the effect of the changes in powering process stage by observing the result of open water efficiency based on Wageningen Data Series with cavitation analysis has been neglected. The study is considered using intersection between propeller thrust with thrust coefficient and open water efficiency on Wageningen B-Series for fixed pitch propeller. The result indicated that propeller characteristic B5-76 with 41% of efficiency  has compatibility with specification of installed main engine.

Structural Design of S-Bend Box for ITER Feeder Based on Optimization Technique of ANSYS

2010 ◽  
Author(s):  
Biao Dong ◽  
Kai-song Wang ◽  
Yun-tao Song
Keyword(s):  
Optimization Design ◽  
Theoretical Calculations ◽  
Structural Parameters ◽  
Optimization Technique ◽  
Equivalent Stress ◽  
Optimal Solution ◽  
Parametric Modeling ◽  
State Variables ◽  
Practical Applications ◽  
Technical Parameters

On the premise that ensuring the reliability of structural strength, and in order to get the optimal structural parameters and the number of reinforcement rib of the ITER feeder S-bend box (SBB), so that its stress distribution is more uniform and reasonable under the critical pressure load, and the cost of materials is relatively smaller, this article, through theoretical calculations and inferences on the basis of the parametric modeling and static analysis and checking of SBB, setting up different reinforcement rib numbers, optimizes through the ANSYS optimization design module, with the maximum stress as the objection function, with and reasonable quality and displacement as state variables, with the size of wall thickness and the space of reinforcement rib as design variables. And it regulates true stress at stress concentration through submodeling of ANSYS and local solid modeling. The results of optimization analysis show that: SBB reached the optimal solution when the reinforcement rib number N of SBB takes 3, the maximum equivalent stress is 117 Mpa and the weight is 6417Kg. Finally, SBB structural parameters, which obtained through optimization design, are rounded according to GB. These meet the design requirements, correspond to the practical applications and provide technical parameters and basis for the future development of SBB.

scholarly journals Multi-objective optimization design of spur gear based on NSGA-II and decision making

2019 ◽  
Vol 11 (3) ◽  
pp. 168781401882493 ◽  
Author(s):  
Qizhi Yao
Keyword(s):  
Decision Maker ◽  
Optimization Design ◽  
Optimal Solution ◽  
Spur Gear ◽  
Optimal Solutions ◽  
Multi Objective Optimization ◽  
Nsga Ii ◽  
Multi Objective ◽  
Deviation Index ◽  
Decision Variables

Optimization design of spur gear is a complicated work because the performance characteristics depend on different types of decision variables and objectives. Traditional single-objective optimization design of the spur gear always results in poor outcomes relative to other objectives due to objectives’ competition with each other. Therefore, this study works on the spur gear design based on the multi-objective optimization model of elitist non-dominated sorting genetic algorithm (NSGA-II). In the model, gear module, teeth number, and transmission ratio are decision variables, while center distance, bearing capacity coefficient, and meshing efficiency are objectives. Final optimal solutions are picked out from Pareto frontier calculated from NSGA-II using the decision makers of Shannon Entropy, linear programming technique for multidimensional analysis of preference (LINMAP), and technique of order preference by similarity to an ideal solution (TOPSIS). Meanwhile, a deviation index is used to evaluate the reasonable status of the optimal solutions. From triple-objective and dual-objective optimization results, it is found that the optimal solution selected from LINMAP decision maker shows a relatively small deviation index. It indicates that LINMAP decision maker may yield better optimal solution. This study could provide some beneficial information for spur design.

Multi-objective optimization design for a magnetorheological damper

2021 ◽  
pp. 1045389X2110069
Author(s):  
Min Jiang ◽  
Xiaoting Rui ◽  
Fufeng Yang ◽  
Wei Zhu ◽  
Yanni Zhang
Keyword(s):  
Optimization Design ◽  
Magnetic Circuit ◽  
Dynamic Range ◽  
Structural Parameters ◽  
Optimal Solution ◽  
Performance Testing ◽  
Mr Damper ◽  
Magnetorheological Damper ◽  
Damping Capacity ◽  
Nsga Ii

As one of the most important components in the semi-active damping system, the performance of MR damper directly determines the damping capacity of the damping system. In order to make the damping system has excellent damping effect, it is necessary to optimize the working performance of the MR damper. Therefore, Non-Dominated Sorting Genetic Algorithm version II (NSGA-II) was applied to optimize the structure of MR dampers in this paper. Firstly, the structural scheme of MR damper was proposed. Secondly, the design principle of MR damper was described, and the magnetic circuit material and MR fluid were selected. Thirdly, taking the maximum dynamic range and the minimum number of turns of electromagnetic coil as the optimization objective, the structure of MR damper was optimized by NSGA-II. The structural parameters of MR damper were determined in the Pareto optimal solution set based on the principle of minimum mass. Finally, through the magnetic simulation and the performance testing of the MR damper, it was verified that the MR damper has reasonable magnetic circuit and excellent performance. And the design results meet the requirements. The proposed optimization method can provide a theoretical basis for the optimal design of related damping devices.

The Effect of Cupping on Four-Quadrant Propeller Performance

2009 ◽  
Author(s):  
Jonathan H. Dowsett ◽  
Phillip S. Duerr ◽  
Jacques B. Hadler ◽  
Robin S. Rose
Keyword(s):  
Test Data ◽  
Open Water ◽  
Performance Characteristics ◽  
Hydrodynamic Performance ◽  
Shaft Speed ◽  
Water Efficiency ◽  
Performance Predictions ◽  
Matching Pair ◽  
Four Quadrant ◽  
Propeller Performance

The Webb Hydroflite Propeller Series (WHPS) consists of four matching pairs of three-bladed ten-inch-diameter pleasure craft propellers with P/D ratios varying from 0.6 to 1.2. Recently, one propeller from each matching pair was modified with a uniform trailing edge cup. Cupping is a widely employed and inexpensive aftermarket alternative to repitching a propeller that is not performing in a given application. The hydrodynamic performance characteristics of each modified propeller were determined by open-water and four-quadrant model tests prior to and after cupping. Performance comparisons were made for each pair of propellers tested to determine the level of manufacturing consistency as well as the effects of cupping. Test data for peak open-water efficiency and four-quadrant performance were compared to B-Series propeller data to determine whether the B-Series can be used confidently for performance predictions. It was found that the addition of the cup could be modeled as an increase in effective pitch. For a given KT/J2 operating curve, the cupped propeller operates at a higher advance coefficient than the original propeller when running ahead. The increase in advance coefficient leads to lower shaft speed at a given thrust. When running astern, there is little change in the KT curve for the cupped propeller and therefore negligible change in advance coefficient but there is a large increase in the required torque at a given shaft speed.

Numerical Analysis of Hydrodynamic Performance of FX-83-W Hydrofoil Current Turbine

2017 ◽  
Author(s):  
Yuchen Shang ◽  
Nikolaos I. Xiros
Keyword(s):  
Numerical Simulation ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Open Water ◽  
Hydrodynamic Performance ◽  
Ocean Current ◽  
Thrust Coefficient ◽  
Cfd Method ◽  
Three Dimensional Coordinate ◽  
Current Turbine

Ocean current flow characteristics are relatively stable and predictable, current turbine absorbs the energy of the ocean currents by the blades with a relative stable and lower angular velocity which indicates the capacity of current turbine greater than the onshore wind turbine. In this paper, the CFD method is utilized to calculate and analyze the working principle of FX-83-W current turbine. The three-dimensional coordinate of FX-83-W Hydrofoil blade surface have been calculated by MATLAB code, and 3D model has been established in Gambit. The basic control equations of CFD and its numerical solution are described, Reynolds Averaged N-S equations is used, and the realizable k-e turbulence model is introduced to solve the Reynolds stress in the RANS equation. The numerical algorithm is the finite volume method (FVM), and the numerical simulation of CFD is used to study the open water performance, leading to thrust coefficient KT and torque coefficient KQ of FX-83-W Hydrofoil. The hydrodynamic thrust and hydrodynamic power of the ocean current turbine under different sea conditions have been obtained by numerical simulation.

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