CFD Simulation of Propeller and Tunnel Thruster Performance

2014 ◽  
Author(s):  
Ping Lu ◽  
Sue Wang
Keyword(s):  
Flow Field ◽  
Cfd Simulation ◽  
Open Water ◽  
Ship Hull ◽  
Hydrodynamic Performance ◽  
Navier Stokes ◽  
Computational Domain ◽  
Flow Features ◽  
Computational Fluid Dynamics Cfd ◽  
Drag And Lift

In the present study, the hydrodynamic performance of a typical North Sea dynamic positioning (DP) shuttle tanker consisting of two main propellers, two rudders, and two bow tunnel thrusters is investigated by solving Reynolds-averaged Navier-Stokes (RANS) equations for a viscous flow. The focus of the numerical simulation is on the performance of propellers/rudders and bow tunnel thrusters considering the hydrodynamic interactions between propellers/thrusters, hull and current. The numerical model includes hull, propeller, rudder, bow tunnel thruster and flow field. First, an analysis of a propeller performance in open water is carried out by calculating the coefficient of thrust, torque, and propeller efficiency. Then, rudders are included in the analysis for the assessment of propeller/rudder performance. The pressure distribution on rudders, rudder’s drag and lift coefficients for different angles of attack, and flow field around the rudder are obtained. The interaction effects between propeller, rudder, ship hull, as well as bow tunnel thruster and ship hull are analyzed by adding detailed ship hull geometry in the computational domain. The tunnel thruster efficiency reduction due to current and ventilation is also analyzed. The presence of current leads to significant changes in the flow velocity and distribution of pressure in the tunnel outflow area as well as significant deflection of the propeller jet emitting from the tunnel. A comparison between Computational Fluid Dynamics (CFD) and model test results of flow features near the tunnel area with various current speeds is presented.

Numerical Simulation of Marine Propeller Hydrodynamic Performance in Uniform Inflow with Different Turbulence Models

2013 ◽  
Vol 389 ◽  
pp. 1019-1025 ◽  
Author(s):  
Mohamed Bennaya ◽  
Jing Feng Gong ◽  
Moutaz M. Hegaze ◽  
Wen Ping Zhang
Keyword(s):  
Turbulence Model ◽  
Turbulence Models ◽  
Open Water ◽  
Hydrodynamic Performance ◽  
Navier Stokes ◽  
Hydrodynamic Characteristics ◽  
Computational Domain ◽  
Acceptable Error ◽  
Marine Propellers ◽  
Fluent Software

In general, marine propellers have complicated geometries and as a consequence complicated flow around propeller. The aim of this work is to find an appropriate method and assess the turbulence model to approach the open water hydrodynamic characteristics of the marine propellers. In this work, a numerical modeling using a finite volume commercial code (FVM) for different turbulence models has been applied on the well known conventional screw propeller DTRC P4119. The 3-D solid model of P4119 is established using pro/E software and for the mesh generation ANSYS-ICEM has been used. Steady Reynolds-Averaged Navier Stokes (RANS) simulations are accomplished using FLUENT software with unstructured mesh in the rotating computational domain and structured mesh for the rest of the domain. The open water performance coefficients, thrust (KT), torque (KQ) and efficiency (η) have been calculated and compared with available experimental data to assess the applicability of different turbulence models for the open water study of propeller. This paper shows that, the accuracy of the CFD based on RANS equations is dependent on the used turbulence model and the RNG K-epsilon turbulence model yields to provide the most accurate results. Also, all the turbulence models via FLUENT software behave the same behavior for the total span of the advance coefficient (J) with two types of result accuracy. All the turbulence models shows high accuracy at low advance coefficient and this accuracy decreases but with an acceptable error till it decreases suddenly at the maximum advance coefficient.

scholarly journals Comparison of CFD Simulation to UAS Measurements for Wind Flows in Complex Terrain: Application to the WINSENT Test Site

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1992 ◽  
Author(s):  
Asmae El Bahlouli ◽  
Alexander Rautenberg ◽  
Martin Schön ◽  
Kjell zum Berge ◽  
Jens Bange ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Cfd Simulation ◽  
Test Site ◽  
Unmanned Aircraft ◽  
Navier Stokes ◽  
Area Index ◽  
Flow Features ◽  
High Turbulence ◽  
Computational Fluid Dynamics Cfd ◽  
Aircraft System

This investigation presents a modelling strategy for wind-energy studies in complex terrains using computational fluid dynamics (CFD). A model, based on an unsteady Reynolds Averaged Navier-Stokes (URANS) approach with a modified version of the standard k-ε model, is applied. A validation study based on the Leipzig experiment shows the ability of the model to simulate atmospheric boundary layer characteristics such as the Coriolis force and shallow boundary layer. By combining the results of the model and a design of experiments (DoE) method, we could determine the degree to which the slope, the leaf area index, and the forest height of an escarpment have an effect on the horizontal velocity, the flow inclination angle, and the turbulent kinetic energy at critical positions. The DoE study shows that the primary contributor at a turbine-relevant height is the slope of the escarpment. In the second step, the method is extended to the WINSENT test site. The model is compared with measurements from an unmanned aircraft system (UAS). We show the potential of the methodology and the satisfactory results of our model in depicting some interesting flow features. The results indicate that the wakes with high turbulence levels downstream of the escarpment are likely to impact the rotor blade of future wind turbines.

The Hydrodynamic Performance Prediction of Ship Hull with Propeller

2011 ◽  
Vol 117-119 ◽  
pp. 598-601
Author(s):  
Hai Long Shen ◽  
Gomri Abdelhak ◽  
Qing Tong Chen ◽  
Yu Min Su
Keyword(s):  
Experimental Data ◽  
Performance Prediction ◽  
Prediction Method ◽  
Turbulence Models ◽  
Open Water ◽  
Ship Hull ◽  
Hydrodynamic Performance ◽  
Computational Results ◽  
Flow Features ◽  
Water Test

This paper describes the hydrodynamic performance prediction of ship hull with propeller by using CFD techniques. As an attempt in investigating the flow features around ship hull equipped with a rotating propeller, open water test, resistance test, and self-propulsion test were conducted. The paper discusses also the applicability of different turbulence models which are used to predict the hydrodynamic performance of the propeller, the hull, and the interaction hull-propeller. The hydrodynamic performance prediction method was gotten and was validated. The computational results were validated against the existing experimental data.

scholarly journals CFD Simulation for Estimating Efficiency of PBCF Installed on a 176K Bulk Carrier under Both POW and Self-Propulsion Conditions

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1192
Author(s):  
Dong-Hyun Kim ◽  
Jong-Chun Park ◽  
Gyu-Mok Jeon ◽  
Myung-Soo Shin
Keyword(s):  
Cfd Simulation ◽  
Open Water ◽  
Navier Stokes ◽  
Water Efficiency ◽  
Ocean Engineering ◽  
Bulk Carrier ◽  
Incompressible Viscous Flow ◽  
Korea Research Institute ◽  
Torque Coefficient ◽  
Viscous Flow Field

In this paper, the efficiency of Propeller Boss Cap Fins (PBCF) installed at the bulk carrier was estimated under both Propeller Open Water (POW) and self-propulsion conditions. For this estimation, virtual model-basin tests (resistance, POW, and self-propulsion tests) were conducted through Computational Fluid Dynamics (CFDs) simulation. In the resistance test, the total resistance and the wake distribution according to ship speed were investigated. In the POW test, changes of thrust, torque coefficient, and open water efficiency on the propeller according to PBCF installation were investigated. Finally, the International Towing Tank Conference (ITTC) 1978 method was used to predict the effect of PBCF installation on self-propulsive coefficient and brake horsepower. For analyzing incompressible viscous flow field, the Reynolds-Averaged Navier–Stokes (RANS) equation with SST k-ω turbulence model was calculated using Star-CCM+ 11.06.010-R8. All simulation results were validated by comparing the results of model tests conducted at the Korea Research Institute of Ships and Ocean Engineering (KRISO). Consequently, for the self-propulsion test with the PBCF, a 1.5% reduction of brake horsepower was estimated in the simulation and a 0.5% reduction of the brake horsepower was estimated in the experiment.

Research on CFD Simulation of the Cement Slurry Mixer

2012 ◽  
Vol 621 ◽  
pp. 196-199
Author(s):  
Shui Ping LI ◽  
Ya Li Yuan ◽  
Lu Gang Shi
Keyword(s):  
Flow Field ◽  
High Performance ◽  
Cfd Simulation ◽  
Structural Parameters ◽  
Internal Flow ◽  
Simulation Method ◽  
Cement Slurry ◽  
Fluid Machinery ◽  
Computational Fluid Dynamics Cfd ◽  
Machinery Design

Numerical simulation method of the internal flow field of fluid machinery has become an important technology in the study of fluid machinery design. In order to obtain a high-performance cement slurry mixer, computational fluid dynamics (CFD) techniques are used to simulate the flow field in the mixer, and the simulation results are studied. According to the analysis results, the structural parameters of the mixer are modified. The results show the mixer under the revised parameters meet the design requirements well. So CFD analysis method can shorten design period and provide valuable theoretical guidance for the design of fluid machinery.

A Verification and Validation Study of CFD Simulation of Wind-Induced Ventilation on Building with Single-Sided Opening

2014 ◽  
Vol 554 ◽  
pp. 696-700 ◽  
Author(s):  
Nur Farhana Mohamad Kasim ◽  
Sheikh Ahmad Zaki ◽  
Mohamed Sukri Mat Ali ◽  
Ahmad Faiz Mohammad ◽  
Azli Abd Razak
Keyword(s):  
Open Source Software ◽  
Natural Ventilation ◽  
Cfd Simulation ◽  
Previous Experiment ◽  
Experimental Methods ◽  
Verification And Validation ◽  
Navier Stokes ◽  
Navier Stokes Equation ◽  
Computational Fluid Dynamics Cfd ◽  
Model Approach

Wind-induced ventilation is widely acknowledged as one of the best approaches for inducing natural ventilation. Computational fluid dynamics (CFD) technique is gaining popularity among researchers as an alternative for experimental methods to investigate the behavior of wind-driven ventilation in building. In this present paper, Reynolds averaged Navier-Stokes equation (RANS) k-ε model approach is considered to simulate the airflow on a simplified cubic building with an opening on a single façade. Preliminary simulation using models from previous experiment indicates the reliability of OpenFOAM, the open source software that will be used in this study. The results obtained in this study will better define options for our future study which aims to explore how different buildings arrays modify the airflow inside and around a naturally ventilated building.

scholarly journals EFFECT OF GALLERIES ON THE WIND FLOW STRUCTURE AND POLLUTANT TRANSPORT WITHIN STREET CANYONS WITH OR WITHOUT FACADE ROUGHNESS ELEMENTS (BALCONIES)

2020 ◽  
Vol 7 (12) ◽  
pp. 45-59
Author(s):  
V. A. Karkoulias ◽  
P. E. Marazioti ◽  
D. P. Georgiou ◽  
E. A. Maraziotis
Keyword(s):  
Flow Field ◽  
Concentration Distribution ◽  
Cfd Simulation ◽  
Field Structure ◽  
Flow Structures ◽  
Street Canyons ◽  
Ansys Fluent ◽  
Roughness Elements ◽  
Computational Fluid Dynamics Cfd ◽  
The Vertical Distribution

This paper investigates how the structure of the flow field and the vertical distribution of the pollutant concentration near the wall facades of street canyons are affected by the presence of some elements such as street level galleries. Numerical results are presented for various gallery geometries in combination with facade roughness elements (balconies) for a canyon of an aspect ratio equal to h/w=2.33. The results were obtained by a Computational Fluid Dynamics (CFD) simulation employing the ANSYS-FLUENT suite that incorporated the k-e turbulent (RNG) model. The simulation generated several flow structures inside the canyon (mainly vortices), whose characteristic properties (e.g. number, strength and size) are discussed in terms of the effect of the galleries on the flow field structure and the roughness generated by the building façade balconies. The results indicate a significant influence on both the flow field structure and the mass concentration distribution of the polluting particles.

RANS Maneuvering Simulation of Esso Osaka With Rudder and a Body-Force Propeller

2005 ◽  
Vol 49 (02) ◽  
pp. 98-120
Author(s):  
Claus D. Simonsen ◽  
Frederick Stern
Keyword(s):  
Flow Field ◽  
Open Water ◽  
Verification And Validation ◽  
Fair Agreement ◽  
Navier Stokes ◽  
Complex Flow ◽  
Flow Problems ◽  
The Difference ◽  
Propeller Geometry ◽  
Flow Study

A simplified potential theory-based infinite-bladed propeller model is coupled with the Reynolds averaged Navier-Stokes (RANS) code CFDSHIP-IOWA to give a model that interactively determines propeller-hull-rudder interaction without requiring detailed modeling of the propeller geometry. Computations are performed for an open-water propeller, for the Series 60 ship sailing straight ahead and for the appended tanker Esso Osaka in different maneuvering conditions. The results are compared with experimental data, and the tanker data are further used to study the interaction among the propeller, hull, and rudder. A comparison between calculated and measured data for the Series 60 ship shows fair agreement, where the computation captures the trends in the flow, that is, the flow structure and the magnitude of the field quantities together with the integral quantities. For the tanker, the flow study reveals a rather complex flow field in the stern region, where the velocity distribution and propeller loading reflect the flow field changes caused by the different maneuvering conditions. The integral quantities, that is, the propeller, hull, and rudder forces, are in fair agreement with experiments. No formal verification and validation are performed, so the present results are related to previous work with verification and validation of the same model, but without the propeller. For the validated cases, the levels of validation are the same as without the propeller, because the validation uncertainties, that is, the combined experimental and simulation uncertainties, are assumed to be the same for both cases. Based on this, validation is obtained for approximately the same cases as for the without-propeller conditions, but the comparison errors, that is, the difference between experiment and calculation, are different. For instance, the difference between computation and experiment for the ship resistance is generally larger with the propeller than without, whereas the opposite is the case for the rudder drag. Summarizing the results, the method shows encouraging results, and taking the effort related to modeling the propeller into account, the method appears to be useful in connection with studies of rudder-propeller-hull related flow problems, where the real propeller geometry cannot be modeled.

scholarly journals CFD Simulation of Pollutant Emission in a Natural Draft Dry Cooling Tower with Flue Gas Injection: Comparison between LES and RANS

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3630
Author(s):  
Guangjun Yang ◽  
Xiaoxiao Li ◽  
Li Ding ◽  
Fahua Zhu ◽  
Zhigang Wang ◽  
...  
Keyword(s):  
Flow Field ◽  
Flue Gas ◽  
Cooling Tower ◽  
Cfd Simulation ◽  
Concentration Field ◽  
Pollutant Concentration ◽  
Pollutant Emission ◽  
Navier Stokes ◽  
Dry Cooling Tower ◽  
Reynolds Average

Accurate prediction of pollutant dispersion is vital to the energy industry. This study investigated the Computational Fluid Dynamics (CFD) simulation of pollutant emission in a natural draft dry cooling tower (NDDCT) with flue gas injection. In order to predict the diffusion and distribution characteristics of the pollutant more accurately, Large Eddy Simulation (LES) was applied to predict the flow field and pollutant concentration field and compared with Reynolds Average Navier-Stokes (RANS) and Unsteady Reynolds Average Navier-Stokes (URANS). The relationship between pollutant concentration pulsation and velocity pulsation is emphatically analyzed. The results show that the flow field and concentration field simulated by RANS and URANS are very close, and the maximum value of LES is about 43 times that of RANS and URANS for the prediction of pollutant concentration in the inner shell of cooling tower. Pollutant concentration is closely related to local flow field velocity. RANS and URANS differ greatly from LES in flow field prediction, especially at the outlet and downwind of cooling tower. Compared with URANS, LES can simulate flow field pulsation with a smaller scale and higher frequency.

Computational Fluid Dynamics (CFD) Mesh Independency Technique for a Propeller Characteristics in Open Water Condition

2015 ◽  
Vol 74 (5) ◽  
Author(s):  
M. Nakisa ◽  
A. Maimun ◽  
Yasser M. Ahmed ◽  
F. Behrouzi ◽  
Jaswar Jaswar ◽  
...  
Keyword(s):  
Independent Solution ◽  
Open Water ◽  
Hydrodynamic Performance ◽  
Marine Propeller ◽  
Propeller Blade ◽  
Laboratory Facilities ◽  
Refinement Method ◽  
Mesh Density ◽  
Computational Fluid Dynamics Cfd ◽  
Marine Laboratory

This paper numerically investigated mesh refinement method in order to obtain a mesh independent solution for a marine propeller working in open water condition.Marine propeller blade geometries, especially of 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. The present research workhas focused on the hydrodynamic propeller coefficients of a LNG carrier Tanaga class such as Kt, Kq and η, with respect to the different advance coefficient (j). Finally, the results of numerical simulation in different mesh density that have been 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.

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