Cavitation Performance of Low Speed Ice-Classed Propeller

2020 ◽  
Author(s):  
Churui Wan ◽  
Zhenghao Liu
Keyword(s):  
Vortex Tube ◽  
Open Water ◽  
Blocking Effect ◽  
Cavitation Flow ◽  
Mixture Flow ◽  
Low Speed ◽  
Cavitation Performance ◽  
Cavitation Tunnel ◽  
Open Water Performance ◽  
Tube Structure

Abstract In the ice breaking condition, on account of the low speed and heavy propeller load, the ship resistance is large, which will aggravate the propeller cavitation and the propeller-induced pressure. In this paper, the cavitation performance of the ice-classed propeller is analyzed by numerical simulation and model experiment. Commercial CFD software was used for the numerical simulations, in which the cavitation flow is solved by Schneer & Sauer cavitaiton model based on a single-fluid multiphase mixture flow approach. Model tests to measure cavitation flow on an ice-classed propeller were carried out in SSSRI K15 Cavitation Tunnel. The size of the test section of SSSRI K15 Cavitation Tunnel is 600mm*600mm. The propeller performances in uniform flow over a range of advance coefficients were carried out in open water test in a towing tank. The diameter (D) of the model propeller was 248mm in this research. Firstly, the open water performance of propeller is numerically studied. Near the design conditions, the numerical results are almost consistent with the test results, with an error of less than 1%. In the case of ice breaking, the blocking effect of ice in front of a propeller is studied. The experiment results show that with the ice block close to the propeller, one or more vortex tube structures are generated between the propeller blade and the ship bottom while the vortex cavitation occurs. Such phenomenon is also found between the propeller and the ice block. When the blocking effect is significant, the stable vortex tube structure will appear and significantly change the cavity shape near the blade. When the distance between the ice and the blade disc exceeds 0.72D, the vortex tube structure will disappear.

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.

Influence of Finite Tip Clearance on the Tip Flow Characteristics of Ducted Propeller

2014 ◽  
Vol 889-890 ◽  
pp. 374-379
Author(s):  
Hao Liang Ni ◽  
Jun Wei Zhou ◽  
Da Zheng Wang
Keyword(s):  
Flow Characteristics ◽  
Open Water ◽  
Tip Clearance ◽  
Blade Surface ◽  
Tip Leakage ◽  
Cavitation Performance ◽  
Ducted Propeller ◽  
Torque Coefficient ◽  
Open Water Performance ◽  
Thrust And Torque

The influence of finite tip clearances on the tip flow characteristics, as well as pressure distribution on blade surface near the tip and open water performance of ducted propeller 19A/Ka4-55 model is studied in this paper. It is discovered that tip leakage vortex (TLV for short) disappears when clearance size reduces to a certain extent (0.08% of the propeller radius in this model). The decreasing of tip clearance size also leads to increasing efficiency and better cavitation performance. Besides, variation of thrust and torque coefficient with clearance size show stepped shape instead of linear.

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.

Open water performance comparison between hub-type and hubless rim driven thrusters based on CFD method

2015 ◽  
Vol 103 ◽  
pp. 55-63 ◽  
Author(s):  
Bao-wei Song ◽  
You-jiang Wang ◽  
Wen-long Tian
Keyword(s):  
Open Water ◽  
Performance Comparison ◽  
Open Water Performance ◽  
Cfd Method

An Investigation Into the Effect of Biofouling on Full-Scale Propeller Performance Using CFD

2019 ◽  
Author(s):  
Soonseok Song ◽  
Yigit Kemal Demirel ◽  
Mehmet Atlar
Keyword(s):  
Open Water ◽  
Full Scale ◽  
Roughness Effect ◽  
Thrust Coefficient ◽  
Propulsion Performance ◽  
Negative Effect ◽  
Precise Prediction ◽  
Torque Coefficient ◽  
Open Water Performance ◽  
Propeller Performance

Abstract The negative effect of biofouling on ship resistance has been investigated since the early days of naval architecture. However, for more precise prediction of fuel consumption of ships, understanding the effect of biofouling on ship propulsion performance is also important. In this study, CFD simulations for the full-scale performance of KP505 propeller in open water, including the presence of marine biofouling, were conducted. To predict the effect of barnacle fouling on the propeller performance, experimentally obtained roughness functions of barnacle fouling were employed in the wall-function of the CFD software. The roughness effect of barnacles of varying sizes and coverages on the propeller open water performance was predicted for advance coefficients ranging from 0.2 to 0.8. From the simulations, drastic effects of barnacle fouling on the propeller open water performance were found. The result suggests that the thrust coefficient decreases while the torque coefficient increases with increasing level of surface fouling, which leads to a reduction of the open water efficiency of the propeller. Further investigations into the roughness effect on the pressure and velocity field, surface pressure and wall shear stress, and propeller vortices were examined.

scholarly journals Manoeuvring forces on azimuthing podded propulsor model

2007 ◽  
Vol 14 (2) ◽  
pp. 3-8 ◽  
Author(s):  
Maciej Reichel
Keyword(s):  
Deflection Angle ◽  
Open Water ◽  
Ship Design ◽  
Experimental Results ◽  
Research Centre ◽  
Test Program ◽  
Towing Tank ◽  
Carrier Model ◽  
Podded Propulsor ◽  
Cavitation Tunnel

Manoeuvring forces on azimuthing podded propulsor model This paper presents the preliminary part of comprehensive manoeuvring open-water tests of a gas carrier model. The paper focuses on open water experiments with an azimuthing podded propulsor. The test program was carried out in the cavitation tunnel and the large towing tank of Ship Hydromechanics Division, Ship Design and Research Centre, Gdańsk. The pod was tested as a pushing unit with a 161.3 mm diameter propeller. Steering forces were measured in the range of advance coefficient from 0.0 to 0.8 combined with the range of deflection angles from -45° up to +45°. Measurements on the pod without propeller were also performed. The experiment results are presented in the form of non-dimensional coefficients in function of advance coefficient and deflection angle. Analysis of the experimental results and the conclusions are presented.

Double Acting Tanker: Experiences from Model Tests and Sea Trials

2005 ◽  
Vol 219 (3) ◽  
pp. 109-119 ◽  
Author(s):  
P Trägärdh ◽  
P Lindell ◽  
N Sasaki
Keyword(s):  
Model Test ◽  
Oil And Gas ◽  
Single Point ◽  
Open Water ◽  
Model Tests ◽  
Water Model ◽  
Research Centre ◽  
Sea Trial ◽  
Cavitation Performance ◽  
Ice Conditions

The acronym DAT stands for double acting tanker, a concept where the ship is designed to run astern in heavy ice conditions while remaining hydrodynamically efficient for ahead propulsion in open water conditions. Two large aframax DATs - 106.000 dwt (deadweight tons) each - have been delivered by Sumitomo Heavy Industries to Fortum Oil and Gas OY. They are the first crude carriers built according to the DAT principle and also the first using pod propulsion from the beginning (Fig. 1). They will also be the world's largest crude carriers with ice class 1A super and are primarily intended for year-round transportation of North Sea crude to Fortum's refineries in the Gulf of Finland. The ships were appointed ‘ship of the year’ in Japan in 2003. SSPA was contracted by Sumitomo Heavy Industries to perform model tests. A comprehensive open water model test programme was used to investigate aspects of resistance and propulsion, manoeuvring, and cavitation performance. As the ship is designed to operate both in ahead and astern conditions for prolonged periods of time, most tests were performed both ahead and astern. Also, a simulation study of dynamic positioning at buoy or floating production, storage offshore (FPSO) loading was made by SSPA. Comprehensive tests of the ship's performance in ice were performed in the ice tank at MARC (Masa-Yards Artic Research Centre). The eight-month model testing and development campaign resulted in a ship with excellent propulsion and manoeuvring performance, especially with regard to the high ice class. Sea trials carried out with ship in August 2002 confirmed the results of the model test. Interesting experiences of the model test campaign and comparison between model test and sea trial results are presented, as well as some examples of single-point mooring simulations.

The Rotating Cavitation Performance of a Centrifugal Pump with a Splitter-Bladed Inducer under Different Rotational Speed

2015 ◽  
Vol 32 (3) ◽  
Author(s):  
XiaoMei Guo ◽  
ZuChao Zhu ◽  
BaoLing Cui ◽  
Yi Li
Keyword(s):  
Centrifugal Pump ◽  
Rotational Speed ◽  
High Speed ◽  
Internal Flow ◽  
Centrifugal Pumps ◽  
Cavitation Flow ◽  
Operation Condition ◽  
Cavitation Performance ◽  
Cavitation Behavior ◽  
Suction Performance

AbstractDesigning inducer is one of the effective ways to improve the suction performance of high-speed centrifugal pumps. The operation condition including rotational speeds can affect the internal flow and external performance of high-speed centrifugal pumps with an inducer. In order to clarify the rotating cavitation performance of a centrifugal pump with a splitter-bladed inducer under different rotational speed, a centrifugal pump with a splitter-bladed inducer is investigated in the work. By using Rayleigh–Plesset equations and Mixture model, the cavitation flow of centrifugal pump is numerically simulated, as well as the external performance experimental test is carried out. It is found that the cavitation area increases with the rotational speeds. The location of the passage where cavitation is easy to appear is explored. Asymmetric cavitation behavior is observed. That, the trail of the inducer is easy to take cavitation when the rotational speed is increased to a degree, is also observed. The trend of

Sign in / Sign up

Export Citation Format

Share Document