scholarly journals Numerical Analysis of Blade Stress of Marine Propellers

2020 ◽  
Vol 19 (3) ◽  
pp. 436-443
Author(s):  
Kai Yu ◽  
Peikai Yan ◽  
Jian Hu
Keyword(s):  
Axial Strain ◽  
Equivalent Stress ◽  
Open Water ◽  
Object A ◽  
Marine Propellers ◽  
Maximum Equivalent Stress ◽  
Tip Position ◽  
Stress And Deformation ◽  
Open Water Performance ◽  
Set Up

Abstract In this study, a series of numerical calculations are carried out in ANSYS Workbench based on the unidirectional fluid–solid coupling theory. Using the DTMB 4119 propeller as the research object, a numerical simulation is set up to analyze the open water performance of the propeller, and the equivalent stress distribution of the propeller acting in the flow field and the axial strain of the blade are analyzed. The results show that FLUENT calculations can provide accurate and reliable calculations of the hydrodynamic load for the propeller structure. The maximum equivalent stress was observed in the blade near the hub, and the tip position of the blade had the largest stress. With the increase in speed, the stress and deformation showed a decreasing trend.

A study on the effect of the rake angle on the performance of marine propellers

2011 ◽  
Vol 226 (4) ◽  
pp. 940-955 ◽  
Author(s):  
A N Hayati ◽  
S M Hashemi ◽  
M Shams
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Design Process ◽  
Flow Characteristics ◽  
Open Water ◽  
Rake Angle ◽  
Marine Propellers ◽  
Propeller Design ◽  
Open Water Performance ◽  
Dynamics Method

In this study, the open water performance of three propellers with diverse rake angles was investigated by computational fluid dynamics method. The objective of this study was to find out the influence of the rake angle on the performance of conventional screw propellers. For this purpose, first, the obtained results for three B-series propellers were validated against the empirical results and then by modifying the rake angle, different models were investigated by the same method. Flow characteristics were examined for the models and the evolvement of vortices on different planes around the propeller were compared. The results suggest that in case of conventional screw propellers with linear rake distribution, while the effect of the rake angle on the propeller efficiency is not significant, the augmentation of this parameter improves the propeller thrust, especially at high propeller loads, but at the same time, the required torque increases, which is not desirable for the propeller design process.

A 3D Computation of Fluid-Structure Interaction in a Cyclone Separator

2014 ◽  
Vol 540 ◽  
pp. 106-109
Author(s):  
Pan Zhang ◽  
Bei Wang ◽  
Zhi Peng Guo ◽  
Ya Nan Shen
Keyword(s):  
Equivalent Stress ◽  
Fluid Structure Interaction ◽  
Cyclone Separator ◽  
The Finite Element Method ◽  
Gas Velocity ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Maximum Equivalent Stress ◽  
Stress And Deformation ◽  
Volume Method

This work presents a 3D computation of fluid-structure interaction in a cyclone separator. The finite volume method was used to simulate the flow field in the cyclone separator. The fluid-structure interaction was conducted by transferring the computational pressure distribution to the corresponding surface of the cyclone shell. The stress and deformation distribution in the cyclone shell was computed by the finite element method. Results obtained show that the maximum equivalent stress and deformation is linearly increases with the increases of the inlet gas velocity.

Open water performance of B-Series marine propellers in tandem configurations

2021 ◽  
Vol 242 ◽  
pp. 110158
Author(s):  
Sachin Amrut Chavan ◽  
Anirban Bhattacharyya ◽  
Om Prakash Sha
Keyword(s):  
Open Water ◽  
Marine Propellers ◽  
Open Water Performance

Application Study of Cartesian Grid in Numerical Prediction of a Marine Propeller

2016 ◽  
Author(s):  
Lang Gu ◽  
Chao Wang ◽  
Jian Hu
Keyword(s):  
Performance Prediction ◽  
Vortex Structure ◽  
Open Water ◽  
Cartesian Grid ◽  
Marine Propellers ◽  
Cavitation Performance ◽  
Vortex Merging ◽  
Flow Field Characteristics ◽  
Open Water Performance ◽  
Thrust And Torque

Cartesian grid was used in open water performance prediction, cavitation performance prediction and flow field characteristics of a propeller to research the applicability of the Cartesian grid in the numerical simulations of marine propellers. The comparisons of calculated results with the previous research and experimental results verify the accuracy of calculations with the grid on the prediction of thrust and torque coefficient and the simulation of cavitation distribution, wake velocity distribution and the vortex structure trajectory. Meanwhile the propulsive performances of Cartesian grid are better than other types of grid with the similar number of nodes. And the turning point of crash performance under cavitation condition and the phenomenon of vortex merging with neighboring vortex structure are excellent agreement with experiments and references.

Burr Minimization in Shaping of Aluminium Alloy-Through Experimental and Stress Analysis Approach

2011 ◽  
Vol 117-119 ◽  
pp. 1602-1605 ◽  
Author(s):  
Atanu Das ◽  
Partha Pratim Saha ◽  
Santanu Das
Keyword(s):  
Shear Stress ◽  
Aluminum Alloy ◽  
Aluminium Alloy ◽  
Equivalent Stress ◽  
Burr Formation ◽  
Angle Distribution ◽  
Great Problem ◽  
Maximum Equivalent Stress ◽  
Stress And Deformation ◽  
Exit Edge

Shaping Burrs are produced at the edge of a workpiece when a cutter exits it. It causes difficulties in manufacturing and assembly stages. Several attempts were made to minimize burr to suppress deburring to improve productivity. Deburring of the surface in shaping operation in railways industry and other industries is a great problem. An investigation on burr formation at the exit edge of aluminum alloy (4600-M) flats in shaping operation is done in this work under dry environment. It is found out that burr is negligible at 150 exit edge bevel angle. Distribution of shear stress is analyzed using FEM to validate the experimental results. It is found that maximum equivalent stress and deformation at different points on the 150 exit edge bevel angle become minimum justifying the experimental observation. Hence, an exit edge bevel of 150 may be adopted to have minimum burr formation.

Stress Analysis of Side Plates on the Logging Truck’s Cable Reel

2011 ◽  
Vol 339 ◽  
pp. 557-560
Author(s):  
Xiu Liu ◽  
Guang Qing Zhang ◽  
Qun Li Wang ◽  
Zheng Wang
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Working Conditions ◽  
Equivalent Stress ◽  
Element Model ◽  
Three Dimension ◽  
Side Plate ◽  
Maximum Equivalent Stress ◽  
Set Up ◽  
Steel Cables

In order to investigate stress distribution of side plates on the logging truck’s cable reel, and find the cause of side plates cracking, an elastic-plastic finite element model of three-dimension is set up. Based on a series of computations, the distributions of displacement and equivalent stress under the working conditions are analyzed, as well as the influence of the number of side plate floors on stress distribution. The results indicate the maximum equivalent stress is on the outside connection between side plate and cable reel, and the floors take the most part loads from steel cables. When the number of floors is greater than 11, increasing the floor number will not decrease the maximum equivalent stress obviously. The conclusion provides useful method and foundation for resolving floor cracking on logging trucks.

scholarly journals Finite Element Modeling of Residual Stress at Joint Interface of Titanium Alloy and 17-4PH Stainless Steel

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 629
Author(s):  
Nana Kwabena Adomako ◽  
Sung Hoon Kim ◽  
Ji Hong Yoon ◽  
Se-Hwan Lee ◽  
Jeoung Han Kim
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stainless Steel ◽  
Finite Element Modeling ◽  
Equivalent Stress ◽  
Stress Gradient ◽  
Joint Interface ◽  
Element Modeling ◽  
Actual Experiment ◽  
Maximum Equivalent Stress

Residual stress is a crucial element in determining the integrity of parts and lifetime of additively manufactured structures. In stainless steel and Ti-6Al-4V fabricated joints, residual stress causes cracking and delamination of the brittle intermetallic joint interface. Knowledge of the degree of residual stress at the joint interface is, therefore, important; however, the available information is limited owing to the joint’s brittle nature and its high failure susceptibility. In this study, the residual stress distribution during the deposition of 17-4PH stainless steel on Ti-6Al-4V alloy was predicted using Simufact additive software based on the finite element modeling technique. A sharp stress gradient was revealed at the joint interface, with compressive stress on the Ti-6Al-4V side and tensile stress on the 17-4PH side. This distribution is attributed to the large difference in the coefficients of thermal expansion of the two metals. The 17-4PH side exhibited maximum equivalent stress of 500 MPa, which was twice that of the Ti-6Al-4V side (240 MPa). This showed good correlation with the thermal residual stress calculations of the alloys. The thermal history predicted via simulation at the joint interface was within the temperature range of 368–477 °C and was highly congruent with that obtained in the actual experiment, approximately 300–450 °C. In the actual experiment, joint delamination occurred, ascribable to the residual stress accumulation and multiple additive manufacturing (AM) thermal cycles on the brittle FeTi and Fe2Ti intermetallic joint interface. The build deflected to the side at an angle of 0.708° after the simulation. This study could serve as a valid reference for engineers to understand the residual stress development in 17-4PH and Ti-6Al-4V joints fabricated with AM.

Optimization of RANS Solver Simulation Setup for Propeller Open Water Performance Prediction

2015 ◽  
Author(s):  
Mohammed Islam ◽  
Fatima Jahra ◽  
Michael Doucet
Keyword(s):  
Domain Size ◽  
Open Water ◽  
Fractional Factorial ◽  
Navier Stokes ◽  
Calm Water ◽  
Simulation Results ◽  
Open Water Performance ◽  
Thrust And Torque ◽  
Simulation Time ◽  
Fixed Pitch

Mesh and domain optimization strategies for a RANS solver to accurately estimate the open water propulsive characteristics of fixed pitch propellers are proposed based on examining the effect of different mesh and computation domain parameters. The optimized mesh and domain size parameters were selected using Design of Experiments (DoE) methods enabling simulations to be carried out in a limited memory environment, and in a timely manner; without compromising the accuracy of results. A Reynolds-Averaged Navier Stokes solver is used to predict the propulsive performance of a fixed pitch propeller. The predicted thrust and torque for the propeller were compared to the corresponding measurements. A total of six meshing parameters were selected that could affect the computational results of propeller open water performance. A two-level fractional factorial design was used to screen out parameters that do not significantly contribute to explaining the dependent parameters: namely simulation time, propeller thrust and propeller torque. A total of 32 simulations were carried out only to find out that the selected six meshing parameters were significant in defining the response parameters. Optimum values of each of the input parameters were obtained for the DOE technique and additional simulations were run with those parameters. The simulation results were validated using open water experimental results of the same propeller. It was found that with the optimized meshing arrangement, the propeller opens simulation time was reduced by at least a factor of 6 as compared to the generally popular meshing arrangement. Also, the accuracy of propulsive characteristics was improved by up to 50% as compared to published simulation results. The methodologies presented in this paper can be similarly applied to other simulations such as calm water ship resistance, ship propulsion to systematically derive the optimized meshing arrangement for simulations with minimal simulation time and maximum accuracy. This investigation was carried out using STAR-CCM+, a commercial CFD package; however the findings can be applied to any RANS solver.

scholarly journals Numerical Simulation and Experimental Study on Axial Stiffness and Stress Deformation of the Braided Corrugated Hose

2021 ◽  
Vol 11 (10) ◽  
pp. 4709
Author(s):  
Dacheng Huang ◽  
Jianrun Zhang
Keyword(s):  
Numerical Simulation ◽  
Geometric Model ◽  
Equivalent Stress ◽  
Element Model ◽  
Maximum Error ◽  
Structural Features ◽  
Axial Stiffness ◽  
Frictional Stress ◽  
Maximum Equivalent Stress ◽  
Simulation Results

To explore the mechanical properties of the braided corrugated hose, the space curve parametric equation of the braided tube is deduced, specific to the structural features of the braided tube. On this basis, the equivalent braided tube model is proposed based on the same axial stiffness in order to improve the calculational efficiency. The geometric model and the Finite Element Model of the DN25 braided corrugated hose is established. The numerical simulation results are analyzed, and the distribution of the equivalent stress and frictional stress is discussed. The maximum equivalent stress of the braided corrugated hose occurs at the braided tube, with the value of 903MPa. The maximum equivalent stress of the bellows occurs at the area in contact with the braided tube, with the value of 314MPa. The maximum frictional stress between the bellows and the braided tube is 88.46MPa. The tensile experiment of the DN25 braided corrugated hose is performed. The simulation results are in good agreement with test data, with a maximum error of 9.4%, verifying the rationality of the model. The study is helpful to the research of the axial stiffness of the braided corrugated hose and provides the base for wear and life studies on the braided corrugated hose.

Model Tests in Brash Ice Channels

2005 ◽  
Author(s):  
Jens-Holger Hellmann ◽  
Karl-Heinz Rupp ◽  
Walter L. Kuehnlein
Keyword(s):  
Perforated Plate ◽  
Ice Sheet ◽  
Open Water ◽  
Model Tests ◽  
Ice Thickness ◽  
Special Device ◽  
Level Ice ◽  
Set Up ◽  
Parental Level ◽  
Oil Tankers

According to the present Finnish-Swedish Ice Class Rules (FSICR) the formulas for the required main engine power for tankers led to much bigger main engines than it is needed for the demanded open water speed. Therefore model tests may be performed in order to verify the vessel’s capability to sail with less required power in brash ice channels compared to the calculations. Several model test runs have been performed in order to study the performance of crude oil tankers sailing in brash ice. The tests were performed as towed propulsion tests and the brash ice channel was prepared according to the guidelines set up by the Finnish Maritime Administration (FMA). The channel width was 2 times the beam of the tanker. The model tests were carried out at a speed of 5 knots. For the tests a parental level ice sheet of adequate thickness is prepared according to HSVA’s standard model ice preparation procedure. After a predefined level ice thickness has been reached, the air temperature in the ice tank will be raised. An ice channel with straight edges will be cut into the ice sheet by means of two ice knives. The ice stripe between the two cuts will be manually broken up into relatively small ice pieces using a special ice chisel and if required the brash ice material will be compacted. Typically the brash ice thickness will be measured prior the tests at 9 positions across the channel and every two meter over the entire length of the brash ice channel with a special device, which consists of a measuring rule with a perforated plate mounted under a right angle at the lower end of the rule. As a result of the tests it could be demonstrated that tankers with a capacity of more than 50 000 tons require 50% and even less power compared to calculations using the present FSICR formulas.

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