Blockage effect influence on model-scale marine propeller performance and cavitation pattern

2022 ◽  
Vol 120 ◽  
pp. 103019
Author(s):  
Eduardo Tadashi Katsuno ◽  
João Lucas Dozzi Dantas
Keyword(s):  
Marine Propeller ◽  
Model Scale ◽  
Propeller Performance ◽  
Blockage Effect

scholarly journals On the Calculation of Propulsive Characteristics of a Bulk-Carrier Moving in Head Seas

2020 ◽  
Vol 8 (10) ◽  
pp. 786
Author(s):  
S. Polyzos ◽  
G. Tzabiras
Keyword(s):  
Navier Stokes ◽  
Bulk Carrier ◽  
Time Step ◽  
Towing Tank ◽  
Model Scale ◽  
Time Period ◽  
Unsteady Rans ◽  
Computational Fluid Dynamics Cfd ◽  
The Time Domain ◽  
Propeller Performance

The present work describes a simplified Computational Fluid Dynamics (CFD) approach in order to calculate the propulsive performance of a ship moving at steady forward speed in head seas. The proposed method combines experimental data concerning the added resistance at model scale with full scale Reynolds Averages Navier–Stokes (RANS) computations, using an in-house solver. In order to simulate the propeller performance, the actuator disk concept is employed. The propeller thrust is calculated in the time domain, assuming that the total resistance of the ship is the sum of the still water resistance and the added component derived by the towing tank data. The unsteady RANS equations are solved until self-propulsion is achieved at a given time step. Then, the computed values of both the flow rate through the propeller and the thrust are stored and, after the end of the examined time period, they are processed for calculating the variation of Shaft Horsepower (SHP) and RPM of the ship’s engine. The method is applied for a bulk carrier which has been tested in model scale at the towing tank of the Laboratory for Ship and Marine Hydrodynamics (LSMH) of the National Technical University of Athens (NTUA).

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.

scholarly journals Effects of Marine Propeller Performance and Parameters Using CFD Method

2014 ◽  
Vol 14 (22) ◽  
pp. 3083-3088 ◽  
Author(s):  
Kiam Beng Yeo ◽  
Rosalam Sabatly ◽  
Wen Yee Hau ◽  
Cheah Meng Ong
Keyword(s):  
Marine Propeller ◽  
Cfd Method ◽  
Propeller Performance

scholarly journals Effect of the blade number on the marine propeller performance

2019 ◽  
Vol 213 ◽  
pp. 02007
Author(s):  
Fatima Bouregba ◽  
Mustapha Belkadi ◽  
Mohammed Aounallah ◽  
Lahouari Adjlout
Keyword(s):  
Open Water ◽  
Stationary Flow ◽  
Computational Domain ◽  
Marine Propeller ◽  
Ansys Fluent ◽  
Marine Propellers ◽  
Blade Number ◽  
Tetrahedral Cells ◽  
Propeller Performance ◽  
Good Agreement

This paper deals with numerical simulation of stationary flow around a marine propeller. The aim is to reproduce the hydrodynamic turbulent flow around the Wageningen B serie propellers in open water using the ANSYS FLUENT code and the RANS approach. The computational domain consists of an inter-blade channel with periodic boundaries, meshed with tetrahedral cells. The turbulence is modeled with the k-ω. The obtained results provide good agreement with the available experimental data and show that the blades number affects considerably the marine propellers performances. It is interesting to notice that the six blades propeller is the best adapted one for the open water flows.

Numerical Computation of Tip Vortex Flow Generated by a Marine Propeller

1999 ◽  
Vol 121 (3) ◽  
pp. 638-645 ◽  
Author(s):  
Chao-Tsung Hsiao ◽  
Laura L. Pauley
Keyword(s):  
Cross Section ◽  
Vortex Flow ◽  
Tip Vortex ◽  
Navier Stokes ◽  
Marine Propeller ◽  
Mean Velocity ◽  
Cavitation Inception ◽  
Section Design ◽  
The Mean ◽  
Propeller Performance

The uniform flow past a rotating marine propeller was studied using incompressible Reynolds-averaged Navier-Stokes computations with the Baldwin-Barth turbulence model. Extensive comparison with the experimental data was made to validate the numerical results. The general characteristics of the propeller flow were well predicted. The current numerical method, however, produced an overly diffusive and dissipative tip vortex core. Modification of the Baldwin-Barth model to better predict the Reynolds stress measurements also improved the prediction of the mean velocity field. A modified tip geometry was also tested to show that an appropriate cross section design can delay cavitation inception in the tip vortex without reducing the propeller performance.

Analysis of Hydrophobic Painting in Model-Scale Marine Propeller

2018 ◽  
Author(s):  
Eduardo Tadashi Katsuno ◽  
Joao Lucas Dozzi Dantas ◽  
Emilio Carlos Nelli Silva
Keyword(s):  
Superhydrophobic Surface ◽  
Slip Length ◽  
Three Dimensional ◽  
Efficiency Gain ◽  
Suction Pressure ◽  
Two Dimensional ◽  
Marine Propeller ◽  
Model Scale ◽  
Drag Ratio ◽  
Lift To Drag Ratio

This paper aims to perform a numerical analysis of application effects of a superhydrophobic paint by completely coating the blades of a model-scale marine propeller in order to make it a superhydrophobic surface (SHS). First, a two-dimensional study was conducted. Two foils were analyzed for several hydrophobic conditions, varying the slip length. Pressure and skin friction distributions were shown. There is an increase of lift-to-drag ratio with hydrophobicity, but followed by an increase in suction pressure. In three-dimensional case, a propeller was simulated for several hydrophobic conditions, comparing thrust, torque and efficiency coefficients and pressure and friction distribution. Results with propeller showed that an increase in slip length is not always followed by an increase in efficiency, with an apparent efficiency gain limit. For the imposed simulation conditions, from the limit of gain, efficiency no longer increases with hydrophobicity, but its area of low pressure continues to grow.

Numerical Analysis of Hydrodynamic Propeller Performance of LNG Carrier in Open Water

2014 ◽  
Vol 66 (2) ◽  
Author(s):  
M. Nakisa ◽  
A. Maimun ◽  
Yasser M. Ahmed ◽  
Jaswar Jaswar ◽  
A. Priyanto ◽  
...  
Keyword(s):  
Open Water ◽  
Hydrodynamic Performance ◽  
Marine Propeller ◽  
Turbulent Model ◽  
Propeller Blade ◽  
Hydrodynamic Parameters ◽  
Laboratory Facilities ◽  
Mesh Density ◽  
Propeller Performance ◽  
Marine Laboratory

Marine propeller blade geometries, especially LNG carriers, are very complicated and determining the hydrodynamic performance of these propellers using experimental work is very expensive, time consuming and has many difficulties in calibration of marine laboratory facilities. This paper presents the assessment on the effect of turbulent model and mesh density on propeller hydrodynamic parameters. Besides that, this paper focuses on the LNG carrier Tanaga class propeller hydrodynamic performance coefficients such as Kt, Kq and η, with respect to the different advance coefficient (j). Finally, the results from numerical simulation that were calculated based on RANS (Reynolds Averaged Navier Stocks) equations, were compared with existing experimental results, followed by analysis and discussion sections. As a result the maximum hydrodynamic propeller efficiency occurred when j=0.84.

scholarly journals Wageningen-B Marine Propeller Performance Characterization Through CFD

2014 ◽  
Vol 14 (11) ◽  
pp. 1215-1219
Author(s):  
Kiam Beng Yeo ◽  
Wai Heng Choong ◽  
Wen Yee Hau
Keyword(s):  
Marine Propeller ◽  
Performance Characterization ◽  
Propeller Performance
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