Numerical Study on the Performance Analysis and Vibration Characteristics of Flexible Marine Propeller

2020 ◽  
Author(s):  
Kumar S. Ashok ◽  
Subramanian V. Anantha ◽  
R. Vijayakumar
Keyword(s):  
Performance Analysis ◽  
Numerical Study ◽  
Open Water ◽  
Simulation Method ◽  
Mode Shapes ◽  
Thrust Coefficient ◽  
Fluid Structure ◽  
Marine Propellers ◽  
Water Characteristics ◽  
Wet Condition

Abstract This paper addresses the hydro-elastic performance of two composite marine propellers at operating condition and compares the results with conventional materials. The study involves three stages namely, design and development of a B series propeller, hydrodynamic and structural performance analysis in uniform flow and free vibration test both in dry and wet condition. In order to perform the hydro-elastic based fluid structure interaction (FSI), Co-Simulation method was adopted to couple Reynolds Averaged Navier-Strokes Equation (RANSE) based Computational Fluid Dynamics (CFD) solver and finite element method (FEM) solvers. The open water characteristics such as thrust coefficient (KT), torque coefficient (KQ), and open water efficiency (ηO) were analyzed as a function of advance velocity (J) of the propeller. A detailed study of the various blade materials by varying mechanical properties are presented. The results obtained show the variation of stress and deflection on the blade, along with the influence of the blade deformation on the performance of propeller. The vibration behaviour of the propellers were also analysed by Block-Lanczos method in FEM solver to obtain the natural frequencies and the mode shapes using Acoustic Fluid-Structure Coupling method for both dry and wet condition. Results showed that composite propeller have better hydro-dynamic property and lower vibration than metal propeller.

scholarly journals A Comparison of Physical and Numerical Modeling of Homogenous Isotropic Propeller Blades

2020 ◽  
Vol 8 (1) ◽  
pp. 21 ◽  
Author(s):  
Luca Savio ◽  
Lucia Sileo ◽  
Sigmund Kyrre Ås
Keyword(s):  
Numerical Modeling ◽  
Open Water ◽  
Computational Approach ◽  
Experimental Setup ◽  
Fluid Structure ◽  
Towing Tank ◽  
Design Procedures ◽  
Structure Interaction ◽  
Marine Propellers ◽  
Propeller Blades

Results of the fluid-structure co-simulations that were carried out as part of the FleksProp project are presented. The FleksProp project aims to establish better design procedures that take into account the hydroelastic behavior of marine propellers and thrusters. Part of the project is devoted to establishing good validation cases for fluid-structure interaction (FSI) simulations. More specifically, this paper describes the comparison of the numerical computations carried out on three propeller designs that were produced in both a metal and resin variant. The metal version could practically be considered rigid in model scale, while the resin variant would show measurable deformations. Both variants were then tested in open water condition at SINTEF Ocean’s towing tank. The tests were carried out at different propeller rotational speeds, advance coefficients, and pitch settings. The computations were carried out using the commercial software STAR-CCM+ and Abaqus. This paper describes briefly the experimental setup and focuses on the numerical setup and the discussion of the results. The simulations agreed well with the experiments; hence, the computational approach has been validated.

Research on the Improved Body-Force Method Based on Viscous Flow

2019 ◽  
Author(s):  
Zhiheng Li ◽  
Jiawei Yu ◽  
Dakui Feng ◽  
Kaijun Jiang ◽  
Yujie Zhou
Keyword(s):  
Drag Coefficient ◽  
Viscous Flow ◽  
Body Force ◽  
Lift Coefficient ◽  
Open Water ◽  
Viscous Effects ◽  
Thrust Coefficient ◽  
Force Method ◽  
Water Characteristics ◽  
Body Force Method

Abstract The virtual propeller model can achieve the rapid numerical prediction of the ship self-propulsion performance through viscous flow, which used the improved body-force method. The two-dimensional lift coefficient CL and the drag coefficient CD are very important parameters in this method, which are generally obtained by the potential flow methods and cannot incorporate viscous effects. This study will perform a fully nonlinear unsteady RANS (Reynolds Average Navier-Stokes) simulation to get the KP505 open-water characteristics and then divide its blade into several parts to get the lift coefficient CL and the drag coefficient CD on each one. Then fitting by multivariate regression method, the relationship between CL, CD and propeller parameters is obtained. The Unsteady Blade Element Theory (UBET) is coupled with RANS in house CFD code HUST-Ship (Hydrodynamic Unsteady Simulation Technology for Ship) to calculate the flow around the propeller. RANS equations are solved by the finite difference method and PISO arithmetic. have been made using structured grid with overset technology. The results show that comparing with the EFD data, the maximum differences of the result of the improved body-force method are 4.32% and 2.7% for the thrust coefficient and the torque coefficient respectively near the propeller operating point.

Fluid-Structure Interaction Analysis of Flexible Marine Propellers

2012 ◽  
Vol 226-228 ◽  
pp. 479-482 ◽  
Author(s):  
Hai Tao Sun ◽  
Ying Xiong
Keyword(s):  
Interaction Analysis ◽  
Fluid Structure Interaction ◽  
Simulation Method ◽  
Solution Procedure ◽  
Boundary Element Methods ◽  
Normal Surface ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Marine Propellers ◽  
System User

The present paper focuses on the fluid-structure interaction of flexible marine propellers. The aim is to develop a simulation method to predict the hydro-elastic performance. To compare with the experimental results, the geometry of propeller DTMB4119 is used. The solution procedure first computes the hydrodynamic pressures due to rigid-blade rotation via the BEM (Boundary Element Methods, BEM). The hydrodynamic pressures are then applied as external normal surface traction for the FEM (Finite Element Methods, FEM) solid model to obtain the deformed geometry. The commercial FEM code is then used to solve the equation of motion in the rotating blade-fixed coordinate system. User-defined subroutines are developed to generate FEM models using 8-node linear solid volumetric elements. Iterations are implemented between BEM and FEM solvers until the solution converges. This study shows that the simulation method developed in this paper is reasonable.

scholarly journals A Numerical Investigation of a Winglet-Propeller using an LES Model

2019 ◽  
Vol 7 (10) ◽  
pp. 333 ◽  
Author(s):  
Zhu ◽  
Gao
Keyword(s):  
Volume Fraction ◽  
Mesh Size ◽  
Open Water ◽  
Tip Vortex ◽  
Vortex Wake ◽  
Time Step ◽  
Thrust Coefficient ◽  
Eddy Simulation ◽  
Water Characteristics ◽  
Les Model

The generation of tip vortex cavitation (TVC) is a common phenomenon in marine propellers. Therefore, it is important to find a way for the effective suppression of TVC. Based on the enlightenment of bionics, a propeller with winglets was numerically investigated by using a large eddy simulation (LES) model and the commercial software STAR-CCM+. Various variables, such as mesh size, number of prism layers, vapor properties and time step, were analyzed using the benchmark MAU5-80 propeller. The open water characteristics calculated for the benchmark propeller were compared with experimental data. The meshes in the region of the tip vortex wake were refined. The power spectral density (PSD) of the thrust coefficient and axial velocity were investigated. The comparison of TVC between the benchmark propeller and the propeller with winglets was studied with the Q-criterion, helicity and volume fraction of the vapor. The strength of the tip vortex wake is weakened by winglets; therefore, the presence of winglets leads to a reduction in vapor volume, which in turn alleviates TVC.

scholarly journals Hydro-elastic analysis of carbon composite marine propeller using co-simulation technique

2019 ◽  
Author(s):  
A Kumar ◽  
V A Subramanian ◽  
R Vijayakumar
Keyword(s):  
Performance Analysis ◽  
Sea Water ◽  
Fibre Composite ◽  
Open Water ◽  
Simulation Technique ◽  
Hydrodynamic Performance ◽  
Marine Propeller ◽  
Carbon Fibre Composite ◽  
Navier Stokes Equation ◽  
Thrust Coefficient

Carbon fibre composite has extremely high strength, low density and no corrosion in sea water. These characteristics make it a favourable alternative for consideration as material for marine screw propellers. The obvious advantages are lightweight propeller, resistance to corrosion, and possibly favourable fatigue characteristics. As against this, the relatively higher flexibility of material needs investigation since change of geometry due to load on the blades can affect the hydrodynamic performance. These materials are reduced stiffness and anisotropic in nature, and therefore hydro-elastic based performance analysis is required to understand their performance in operating condition. The current study focuses on numerical investigation for the hydro-elastic based performance analysis of a composite marine propeller in open water condition. The procedure involves the coupling of  Reynolds-Averaged Navier-Stokes Equation (RANSE) based Computational Fluid Dynamics (CFD) solver with the Finite Element Method (FEM) solver using Co-Simulation technique. The open water characteristics including thrust coefficient (KT), torque coefficient (KQ), and open water efficiency (ηo ) analyzed as a function of the advance ratio (J). This paper presents a comparison of the hydrodynamic performance between the composite propeller and a conventional steel propeller taking into account the structural response under loading. The results for the composite propeller show improved thrust value in comparison with the conventional metallic propeller.

Numerical study of the aerodynamic and power characteristics of the cycloidal rotor, under incoming flow

2019 ◽  
pp. 25-34
Author(s):  
Александр Анатольевич Дектерев ◽  
Артем Александрович Дектерев ◽  
Юрий Николаевич Горюнов
Keyword(s):  
Flow Velocity ◽  
Numerical Study ◽  
Lift Coefficient ◽  
Simulation Method ◽  
Aerodynamic Characteristics ◽  
Incoming Flow ◽  
Ansys Fluent ◽  
Energy Characteristics ◽  
Power Characteristics ◽  
Calculation Results

Исследование направлено на разработку и апробацию методики численного моделирования аэродинамических и энергетических характеристик циклоидального ротора. За основу взята конфигурация ротора IAT21 L3. Для нее с использованием CFD-пакета ANSYS Fluent построена математическая модель и выполнен расчет. Проанализировано влияние скорости набегающего потока воздуха на движущийся ротор. Математическая модель и полученные результаты исследования могут быть использованы при создании летательных аппаратов с движителями роторного типа. This article addresses the study of the aerodynamic and energy characteristics of a cycloidal rotor subject to the influence of the incoming flow. Cycloidal rotor is one of the perspective devices that provide movement of aircrafts. Despite the fact that the concept of a cycloidal rotor arose in the early twentieth century, the model of a full-scale aircraft has not been yet realized. Foreign scientists have developed models of aircraft ranging in weight from 0.06 to 100 kg. The method of numerical calculation of the cycloidal rotor from the article [1] is considered and realized in this study. The purpose of study was the development and testing of a numerical simulation method for the cycloidal rotor and study aerodynamic and energy characteristics of the rotor in the hovering mode and under the influence of the oncoming flow. The aerodynamic and energy characteristics of the cycloidal rotor, rotating at a speed of 1000 rpm with incoming flow on it with velocities of 20-80 km/h, were calculated. The calculation results showed a directly proportional increase of thrust with an increase of the incoming on the rotor flow velocity, but the power consumed by the rotor was also increased. Increase of the incoming flow velocity leads to the proportional increasing of the lift coefficient and the coefficient of drag. Up to a speed of 80 km/h, an increase in thrust and power is observed; at higher speeds, there is a predominance of nonstationary effects and difficulties in estimating the aerodynamic characteristics of the rotor. In the future, it is planned to consider the 3D formulation of the problem combined with possibility of the flow coming from other sides.

Numerical Study for Global Detection of Cracks Embedded in Beams

1999 ◽  
Author(s):  
S. A. Lipsey ◽  
Y. W. Kwon
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Natural Frequency ◽  
Mode Shape ◽  
Numerical Study ◽  
Element Model ◽  
Mode Shapes ◽  
Linear Effect ◽  
Modes Of Vibration ◽  
Damage Simulation

Abstract Damage reduces the flexural stiffness of a structure, thereby altering its dynamic response, specifically the natural frequency, damping values, and the mode shapes associated with each natural frequency. Considerable effort has been put into obtaining a correlation between the changes in these parameters and the location and amount of the damage in beam structures. Most numerical research employed elements with reduced beam dimensions or material properties such as modulus of elasticity to simulate damage in the beam. This approach to damage simulation neglects the non-linear effect that a crack has on the different modes of vibration and their corresponding natural frequencies. In this paper, finite element modeling techniques are utilized to directly represent an embedded crack. The results of the dynamic analysis are then compared to the results of the dynamic analysis of the reduced modulus finite element model. Different modal parameters including both mode shape displacement and mode shape curvature are investigated to determine the most sensitive indicator of damage and its location.

Fluid-structure interaction computational analysis and experiments of tsunami bore forces on coastal bridges

2021 ◽  
Vol 31 (5) ◽  
pp. 1373-1395
Author(s):  
Iman Mazinani ◽  
Mohammad Mohsen Sarafraz ◽  
Zubaidah Ismail ◽  
Ahmad Mustafa Hashim ◽  
Mohammad Reza Safaei ◽  
...  
Keyword(s):  
Tsunami Wave ◽  
Numerical Study ◽  
Fluid Structure Interaction ◽  
Indian Ocean Tsunami ◽  
Fluid Structure ◽  
Content Type ◽  
Coastal Bridges ◽  
Structure Interaction ◽  
Wave Flume ◽  
Wave Heights

Purpose Two disastrous Tsunamis, one on the west coast of Sumatra Island, Indonesia, in 2004 and another in North East Japan in 2011, had seriously destroyed a large number of bridges. Thus, experimental tests in a wave flume and a fluid structure interaction (FSI) analysis were constructed to gain insight into tsunami bore force on coastal bridges. Design/methodology/approach Various wave heights and shallow water were used in the experiments and computational process. A 1:40 scaled concrete bridge model was placed in mild beach profile similar to a 24 × 1.5 × 2 m wave flume for the experimental investigation. An Arbitrary Lagrange Euler formulation for the propagation of tsunami solitary and bore waves by an FSI package of LS-DYNA on high-performance computing system was used to evaluate the experimental results. Findings The excellent agreement between experiments and computational simulation is shown in results. The results showed that the fully coupled FSI models could capture the tsunami wave force accurately for all ranges of wave heights and shallow depths. The effects of the overturning moment, horizontal, uplift and impact forces on a pier and deck of the bridge were evaluated in this research. Originality/value Photos and videos captured during the Indian Ocean tsunami in 2004 and the 2011 Japan tsunami showed solitary tsunami waves breaking offshore, along with an extremely turbulent tsunami-induced bore propagating toward shore with significantly higher velocity. Consequently, the outcomes of this current experimental and numerical study are highly relevant to the evaluation of tsunami bore forces on the coastal, over sea or river bridges. These experiments assessed tsunami wave forces on deck pier showing the complete response of the coastal bridge over water.

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