Hydrodynamic Performance and Cavitation of an Open Propeller in a Simulated Ice-Blocked Flow

1994 ◽  
Vol 116 (3) ◽  
pp. 185-189 ◽  
Author(s):  
D. Walker ◽  
N. Bose ◽  
H. Yamaguchi
Keyword(s):  
Uniform Flow ◽  
Full Scale ◽  
Hydrodynamic Performance ◽  
Mean Values ◽  
Cavitation Tunnel ◽  
Propeller Performance ◽  
Thrust And Torque

Experiments were done on a 200-mm-dia open propeller behind a simulated ice blockage in a cavitation tunnel. The propeller performance in uniform flow and blocked flow is contrasted over a range of advance coefficients and at different cavitation numbers. Mean thrust and torque coefficients are presented. The types of cavitation, and its intermittent nature over a cycle of operation, are reported. The experiments indicate the likelihood of cavitation at full scale for blocked conditions and illustrate the effects of cavitation on mean values of thrust and torque.

Numerical investigation of the rake angle effect on the hydrodynamic performance of propeller in a uniform and nonuniform flow

2019 ◽  
Vol 233 (18) ◽  
pp. 6326-6338
Author(s):  
Hasan Sajedi ◽  
Miralam Mahdi
Keyword(s):  
Open Water ◽  
Rake Angle ◽  
Uniform Flow ◽  
Wake Flow ◽  
Hydrodynamic Performance ◽  
Experimental Result ◽  
Nonuniform Flow ◽  
Solution Scheme ◽  
Propeller Performance ◽  
Thrust And Torque

Marine propeller always operates in the wake of a vehicle (ship, torpedo, submarine) but (due to the high computational cost of simulating vehicle and propeller simultaneously) to investigate the propeller geometric parameters, simulations are usually performed in open-water conditions. In this article, using the computational fluid dynamics method with the control volume approach, the effect of the rake angle on the propeller performance and formation of cavitation in the uniform flow (open water) and the nonuniform flow (wake flow) was investigated. In the nonuniform condition, the array of plates was used to simulate wake at upstream propeller. For uniform flow, steady solution scheme was adopted and for nonuniform flow unsteady solution scheme was adopted, and a moving mesh zone was generated around the propeller. To simulate cavitation a multiphase mixture flow, the Reynolds-averaged Navier–Stokes method was used and modeled by Schnerr Sauer's cavitation model. First, the E779a propeller model for numerical validation in the uniform flow and nonuniform flow was investigated. Numerical results were compared with the experimental result, and there was a good agreement between volume of the cavity, thrust, and torque coefficients. To study the effect of rake angle on the performance of B-series propellers, four models with different rake angles were modeled, and simulation was investigated behind the wake. The results of thrust, torque coefficients, and cavitation volume according to the flow parameters and cavitation number were presented as graphs. The results reveals that in the uniform flow, the rake angle has no significant effect on the propeller performance, but behind the wake flow, increase of rake causes to reduce the force applied to the propeller blades, cavitation volume, and pressure fluctuations on the propeller.

scholarly journals Numerical Investigation of the Hydrodynamic Performance of the Propeller Behind the Ship with and Without Wed

2020 ◽  
Vol 27 (4) ◽  
pp. 50-59
Author(s):  
Alireza Nadery ◽  
Hassan Ghassemi
Keyword(s):  
Pressure Pulse ◽  
Wake Flow ◽  
Hydrodynamic Performance ◽  
Analysis Software ◽  
Experiment Method ◽  
The Face ◽  
Computational Fluid Dynamics Cfd ◽  
Propeller Performance ◽  
Thrust And Torque ◽  
Face Side

AbstractThe presented paper numerically carries out the investigation of the hydrodynamic performance of the propeller behind the ship with and without wake equalizing duct (WED). It is mounted in front of the propeller in order to equalize the ship’s wake flow and improve the propeller performance. The computational fluid dynamics (CFD) analysis software STAR-CCM solver was adopted to simulate the KP505 propeller behind the KRISO container ship (KCS) using overlapping grid technology and user-defined functions. To obtain the effect of a –duct on propeller performance, the ship bare hull case, the with-propeller case, and the with-propeller-and-duct case are also computed. Together, these computations provide for a –complete CFD comparison of the duct effects. Also, the Taguchi design of the experiment method is applied to investigate three parameters (angle of attack, trailing edge radius, and chord length) of the duct. Finally, the main dimensions are obtained, and the thrust and torque coefficients are presented and discussed for one blade and whole blades during one cycle. Based on the numerical results, it is indicated that good design increases efficiency by 1.67%, and a –bad design may reduce efficiency by 3.25%. Also, the effect of the WED caused to decrease the pressure pulse by 35.9% in the face side of the propeller blade.

scholarly journals Numerical Analysis of Full-Scale Ship Self-Propulsion Performance with Direct Comparison to Statistical Sea Trail Results

2020 ◽  
Vol 8 (1) ◽  
pp. 24 ◽  
Author(s):  
Wenyu Sun ◽  
Qiong Hu ◽  
Shiliang Hu ◽  
Jia Su ◽  
Jie Xu ◽  
...  
Keyword(s):  
Free Surface ◽  
Numerical Simulations ◽  
Scale Effect ◽  
Full Scale ◽  
Hydrodynamic Performance ◽  
Local Flow ◽  
Model Scale ◽  
Propulsion Performance ◽  
The Difference ◽  
Thrust And Torque

Accurate prediction of the self-propulsion performance is one of the most important factors for the energy-efficient design of a ship. In general, the hydrodynamic performance of a full-scale ship could be achieved by model-scale simulation or towing tank tests with extrapolations. With the development of CFD methods and computing power, directly predict ship performance with full-scale CFD is an important approach. In this article, a numerical study on the full-scale self-propulsion performance with propeller operating behind ship at model- and full-scale is presented. The study includes numerical simulations using the RANS method with a double-model and VOF (Volume-of-Fluid) model respectively and scale effect analysis based on overall performance, local flow fields and detailed vortex identification. The verification study on grid convergence is also performed for full-scale simulation with global and local mesh refinements. A series of sea trail tests were performed to collect reliable data for the validation of CFD predictions. The analysis of scale effect on hull-propeller interaction shows that the difference of hull boundary layer and flow separation is the main source of scale effect on ship wake. The results of the fluctuations of propeller thrust and torque along with circulation distribution and local flow field show that the propeller’s loading is significantly higher for model-scale ship. It is suggested that the difference of vortex evolution and interaction is more pronounced and has larger effects on the ship’s powering performance at model-scale than full-scale according to the simulation results. From the study on self-propulsion prediction, it could be concluded that the simplification on free surface treatment does not only affect the wave-making resistance for bare hull but also the propeller performance and propeller induced ship resistance which can be produced up to 5% uncertainty to the power prediction. Roughness is another important factor in full-scale simulation because it has up to an approximately 7% effect on the delivery power. As a result of the validation study, the numerical simulations of full-scale ship self-propulsion shows good agreement with the sea trail data especially for cases that have considered both roughness and free surface effects. This result will largely enhance our confidence to apply full-scale simulation in the prediction of ship’s self-propulsion performance in the future ship designs.

scholarly journals Numerical Analysis of Full-scale Ship Self-Propulsion Performance with direct Comparison to Statistical Sea Trail Results

2019 ◽  
Author(s):  
Wenyu Sun ◽  
Qiong Hu ◽  
Shiliang Hu ◽  
Jia Su ◽  
Jie Xu ◽  
...  
Keyword(s):  
Free Surface ◽  
Numerical Simulations ◽  
Scale Effect ◽  
Full Scale ◽  
Hydrodynamic Performance ◽  
Local Flow ◽  
Model Scale ◽  
Propulsion Performance ◽  
The Difference ◽  
Thrust And Torque

Accurate prediction of the self-propulsion performance is one of the most important factors for energy-efficient design of a ship. In general, the hydrodynamic performance of a full-scale ship could be achieved by model-scale simulation or towing tank test with extrapolations. With the development of CFD methods and computing power, directly predict ship performance with full-scale CFD is an important approach. In this article, a numerical study on the full-scale self-propulsion performance with propeller operating behind ship at model- and full-scale is presented. The study includes numerical simulations using RANS method with double-model and VOF model respectively and scale effect analysis based on overall performance, local flow fields and detailed vortex identification. Verification study on grid convergence is also performed for full-scale simulation with global and local mesh refinements. And a series of sea trail tests were performed to collect reliable data for the validation of CFD predictions. The analysis of scale effect on hull-propeller interaction shows that the difference on hull boundary layer and flow separation is the main source of scale effect on ship wake. And the results of the fluctuations of propeller thrust and torque along with circulation distribution and local flow field show that propeller’s loading is significantly higher for model-scale ship. It is suggested that the difference on vortex evolution and interaction is more pronounced and have larger effects on ship’s powering performance at model-scale than full-scale according to the simulation results. From the study on self-propulsion prediction, it could be concluded that the simplification on free surface treatment does not only affect the wave-making resistance for bare hull but also the propeller performance and propeller induced ship resistance which can produced up to 5% uncertainty to the power prediction. Roughness is another important factor in full-scale simulation because it has up to approximately 7% effect on the delivery power. As a result of validation study, the numerical simulations of full-scale ship self-propulsion shows good agreement with the sea trail data especially for cases that have considered both roughness and free surface effects. This result will largely enhance our confidence to apply full-scale simulation in the prediction of ship’s self-propulsion performance in the future ship designs.

scholarly journals Experimental research on marine podded propulsors

1970 ◽  
Vol 4 (2) ◽  
pp. 57-71 ◽  
Author(s):  
Mohammed F Islam ◽  
Brian Veitch ◽  
Pengfei Liu
Keyword(s):  
Open Water ◽  
Hydrodynamic Performance ◽  
Prediction Methods ◽  
Taper Angle ◽  
Propulsive Performance ◽  
Water Conditions ◽  
Cavitation Tunnel ◽  
Experimental Side ◽  
Marine Engineering ◽  
Thrust And Torque

This paper describes a research program on podded propulsors that combines parallel developments in numerical prediction methods and experimental evaluation. Amongst the hydrodynamic issues that have been identified and addressed are questions regarding the effects of hub taper angle, pod-strut configurations, static azimuthing conditions, pod-strut interactions, gap pressure, pod gap and pod-strut geometry on podded propulsors' performance. On the experimental side, a pod dynamometer system consisting of a six-component global dynamometer and a three-component pod dynamometer were designed, manufactured and used to perform measurements on propeller thrust and torque and unit forces and moments in the three orthogonal directions in pusher and puller configurations in open water conditions. Four propellers with the same blade sections but different hub taper angles were designed and used to fit with eighteen pod-strut shells. Among the shells, two pod-strut models were based on the average dimensions of commercial pods and used to study the hub angle, pod configuration, pod gap, gap pressure and azimuthing conditions effect on propulsive performance. The other sixteen pods were designed and manufactured to study the effect of five geometric parameters on hydrodynamic performance using a design of experiments technique. In another study, an experimental method was implemented in a cavitation tunnel to evaluate the wake/strut interaction of a podded propeller model. All of the measurements showed consistency.DOI: http://dx.doi.org/10.3329/jname.v4i2.989 Journal of Naval Architecture and Marine Engineering Vol.4(2) 2007 p 57-71

Experimental Performance of a Trochoidal Propeller with High-Aspect-Ratio Blades

1989 ◽  
Vol 26 (03) ◽  
pp. 192-201 ◽  
Author(s):  
Neil Bose ◽  
Peter S. K. Lai
Keyword(s):  
Aspect Ratio ◽  
High Efficiency ◽  
Open Water ◽  
Finite Amplitude ◽  
Dynamic Stall ◽  
Frictional Drag ◽  
Overall Performance ◽  
Small Ship ◽  
Propeller Performance ◽  
Thrust And Torque

Open-water experiments were done on a model of a cycloidal-type propeller with a trochoidal blade motion. This propeller had three blades with an aspect ratio of 10. These experiments included the measurement of thrust and torque of the propeller over a range of advance ratios. Tests were done for forward and reverse operation, and at zero speed (the bollard pull condition). Results from these tests are presented and compared with: a multiple stream-tube theoretical prediction of the performance of the propeller; and a prediction of the performance of a single blade of the propeller, oscillating in heave and pitch, using unsteady small-amplitude hydrofoil theory with corrections for finite amplitude motion, finite span, and frictional drag. At present, neither of these theories gives a completely accurate prediction of propeller performance over the whole range of advance ratios, but a combination of these approaches, with an allowance for dynamic stall of the blades, should lead to a reliable simple theory for overall performance prediction. Application of a propeller of this type to a small ship is discussed. The aim of the design is to produce a lightly loaded propeller with a high efficiency of propulsion.

A study on the efficient numerical analysis for the prediction of full-scale propeller performance using CFD

2021 ◽  
Vol 240 ◽  
pp. 109931
Author(s):  
Kwan-Woo Kim ◽  
Kwang-Jun Paik ◽  
Ju-Han Lee ◽  
Soon-Seok Song ◽  
Mehmet Atlar ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Full Scale ◽  
Propeller Performance

scholarly journals Numerical Analysis on the Effect of Artificial Ventilated Pipe Diameter on Hydrodynamic Performance of a Surface-Piercing Propeller

2019 ◽  
Vol 7 (8) ◽  
pp. 240
Author(s):  
Gao ◽  
Yang ◽  
Li ◽  
Dong
Keyword(s):  
High Speed ◽  
Water Immersion ◽  
Active Role ◽  
Numerical Results ◽  
Hydrodynamic Performance ◽  
Pipe Diameter ◽  
Pressure Area ◽  
Cfd Method ◽  
Thrust And Torque ◽  
Surface Piercing Propeller

Under the condition of large water immersion, surface-piercing propellers are inclined to be heavy loaded. In order to improve the hydrodynamic performance of the surface-piercing propeller, the installation of a vent pipe in front of a propeller disc is more widely used in the propulsion device of high speed planning crafts. Based on computational fluid dynamics (CFD) method, this paper studied the influence of diverse vent pipe diameters on hydrodynamic performance of the surface-piercing propeller under full water immersion conditions. The numerical results show that, with the increase of vent pipe diameters, the thrust and torque of the surface-piercing propeller decrease after ventilation, and the efficiency of the propeller increases rapidly; the low pressure area near the back root of the blade becomes smaller and smaller gradually; and the peak of periodic vibration of thrust and torque can be effectively reduced. The numerical results demonstrate that the installation of artificial vent pipe effectively improves the hydrodynamic performance of surface piercing propeller in the field of high speed crafts, and the increase of artificial vent pipe diameter plays an active role in the propulsion efficiency of the surface-piercing propeller.

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 Cavitation on Model- and Full-Scale Marine Propellers: Steady And Transient Viscous Flow Simulations At Different Reynolds Numbers

2020 ◽  
Vol 8 (2) ◽  
pp. 141 ◽  
Author(s):  
Ville Viitanen ◽  
Timo Siikonen ◽  
Antonio Sánchez-Caja
Keyword(s):  
Reynolds Number ◽  
Numerical Simulations ◽  
Full Scale ◽  
Tip Vortex ◽  
Wake Flow ◽  
Time Step ◽  
Two Phase ◽  
Marine Propellers ◽  
Model Scale ◽  
Propeller Performance

In this paper, we conducted numerical simulations to investigate single and two-phase flows around marine propellers in open-water conditions at different Reynolds number regimes. The simulations were carried out using a homogeneous compressible two-phase flow model with RANS and hybrid RANS/LES turbulence modeling approaches. Transition was accounted for in the model-scale simulations by employing an LCTM transition model. In model scale, also an anisotropic RANS model was utilized. We investigated two types of marine propellers: a conventional and a tip-loaded one. We compared the results of the simulations to experimental results in terms of global propeller performance and cavitation observations. The propeller cavitation, near-blade flow phenomena, and propeller wake flow characteristics were investigated in model- and full-scale conditions. A grid and time step sensitivity studies were carried out with respect to the propeller performance and cavitation characteristics. The model-scale propeller performance and the cavitation patterns were captured well with the numerical simulations, with little difference between the utilized turbulence models. The global propeller performance and the cavitation patterns were similar between the model- and full-scale simulations. A tendency of increased cavitation extent was observed as the Reynolds number increases. At the same time, greater dissipation of the cavitating tip vortex was noted in the full-scale conditions.

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