Numerical Study of a Six-Bladed Savonius Wind Turbine

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Binyet Emmanuel ◽  
Wang Jun
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Study ◽  
The Self ◽  
Power Coefficient ◽  
Two Dimensional ◽  
Savonius Rotor ◽  
Convex Part ◽  
Computational Fluid Dynamics Cfd ◽  
Savonius Wind Turbine

The aim of the present paper is to investigate ways of improving the efficiency of a six-bladed Savonius rotor. The efficiency of Savonius machines is low because of the “negative drag” exerted on the convex part of the blades and also because the torque of standard Savonius rotors varies substantially during one rotation and therefore affects the self starting of the rotor at certain wind angles. Improvement of the efficiency of the Savonius rotor is carried out by increasing the number of blades and also by preventing the wind from impinging on the convex parts. The latter can be done by hiding the convex part of the blades behind a shield or a vane. The present paper shows the results of two-dimensional computational fluid dynamics (CFD) computations, indicating a promising increase of the power coefficient from 0.3 to 0.5.

Computational Fluid Dynamics Techniques for Flows in Lapple Cyclone Separator

2005 ◽  
Vol 498-499 ◽  
pp. 179-185
Author(s):  
A.F. Lacerda ◽  
Luiz Gustavo Martins Vieira ◽  
A.M. Nascimento ◽  
S.D. Nascimento ◽  
João Jorge Ribeiro Damasceno ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Turbulent Flow ◽  
Reynolds Stress ◽  
Cyclone Separator ◽  
Two Dimensional ◽  
Stress Components ◽  
Computational Fluid Dynamics Cfd

A two-dimensional fluidynamics model for turbulent flow of gas in cyclones is used to evaluate the importance of the anisotropic of the Reynolds stress components. This study presents consisted in to simulate through computational fluid dynamics (CFD) package the operation of the Lapple cyclone. Yields of velocity obtained starting from a model anisotropic of the Reynolds stress are compared with experimental data of the literature, as form of validating the results obtained through the use of the Computational fluid dynamics (Fluent). The experimental data of the axial and swirl velocities validate numeric results obtained by the model.

CFD-BASED RESEARCH ON THE LOAD-BEARING CAPACITY OF ASYMMETRIC TEXTURE WITH DIFFERENT REYNOLDS NUMBER

2013 ◽  
Vol 20 (05) ◽  
pp. 1350043 ◽  
Author(s):  
YUNCAI ZHAO ◽  
LEI HAN
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Reynolds Number ◽  
Bearing Capacity ◽  
Two Dimensional ◽  
Hydrodynamic Load ◽  
Cfd Model ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Computational Fluid Dynamics Cfd

A two-dimensional computational fluid dynamics (CFD) model was developed to study the load-bearing capacity of asymmetric texture under the state of fluid lubrication. The effects of asymmetric parameter H and the Reynolds number Re on hydrodynamic load-bearing capacity of the oil film were discussed. It was found that a decrease in asymmetric parameter H may significantly improve the load-bearing capacity, but an increase in Reynolds number Re may reduce this effect. For example, with a Re at 20, the load-bearing capacity increases by 73.44% with the H varying from 4 to 0.2. However, with a Re at 160, it has only an increase of 4.68% at the same conditions. In addition, the numerical results also showed that the load-bearing capacity will increase with the increase of Re in certain texture.

Two-Dimensional Analysis of Tandem/Staggered Airfoils Using Computational Fluid Dynamics

2005 ◽  
Vol 33 (3) ◽  
pp. 195-207 ◽  
Author(s):  
Z. Husain ◽  
M. Z. Abdullah ◽  
T. C. Yap
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Tunnel ◽  
Dimensional Analysis ◽  
Lift Coefficient ◽  
Open Circuit ◽  
Computational Method ◽  
Two Dimensional ◽  
Optimum Position ◽  
Computational Fluid Dynamics Cfd

The two-dimensional analysis, using computational fluid dynamics (CFD), of tandem/staggered arranged airfoils of the canard and wing of an Eagle 150 aircraft and also the aerodynamic tests conducted in an open-circuit wind tunnel are presented in the paper. The wind tunnel tests were carried out at a speed of 38m/s in a test section of size 300 mm (width), 300 mm (height) and 600 mm (length), at Reynolds number 2.25 × 105. The tests were carried out with tandem and staggered placement of the airfoils in order to determine the optimum position of the wing with respect to the canard and also to determine the lift coefficient at various angles of attack. The CFD code FLUENT 5 was used to investigate the aerodynamic performance of a two-dimensional model to validate the wind tunnel results. The flow interaction was studied in the tandem and staggered arrangements in the wind tunnel as well as by the computational method. The k-ε turbulence model gave exceptionally good results.

Computational fluid dynamics study of Savonius rotors using OpenFOAM

2020 ◽  
pp. 0309524X2092495
Author(s):  
Federico González Madina ◽  
Alejandro Gutiérrez ◽  
Pedro Galione
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Vertical Axis ◽  
Aerodynamic Performance ◽  
Dynamics Simulation ◽  
Power Coefficient ◽  
Small Scale ◽  
Two Dimensional ◽  
Discretization Schemes ◽  
Set Up

In this work, two-dimensional models of Savonius rotors are simulated using OpenFOAM® in order to predict the aerodynamic performance of small-scale vertical-axis wind turbines. The results are reported analyzing the aerodynamic performance and forces acting on the rotors. Power coefficient, [Formula: see text], is compared with experimental data for each operation point, and for three different geometries. Simulations with first- and second-order discretization schemes are carried out and compared, both quantitative and qualitative. Since usual grid dimensions result not to be suitable for simulations of Savonius rotors, an analysis of different domains is performed and compared. Finally, a set up for computational fluid dynamics simulation of two-dimensional Savonius rotors is proposed. The fluid–rotor interaction is analyzed and the vortex shedding is correlated with [Formula: see text] values and wake description.

scholarly journals Trim Influence on Kriso Container Ship (KCS): An Experimental and Numerical Study

2017 ◽  
Author(s):  
Emil Shivachev ◽  
Mahdi Khorasanchi ◽  
Alexander H. Day
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Study ◽  
Computational Cost ◽  
Breaking Waves ◽  
Computational Techniques ◽  
Container Ship ◽  
Towing Tank ◽  
Operational Life ◽  
Computational Fluid Dynamics Cfd

There has been a lot of interest in trim optimisation to reduce fuel consumption and emissions of ships. Many existing ships are designed for a single operational condition with the aim of producing low resistance at their design speed and draft with an even keel. Given that a ship will often sail outside this condition over its operational life and moreover some vessels such as LNG carriers return in ballast condition in one leg, the effect of trim on ships resistance will be significant. Ship trim optimization analysis has traditionally been done through towing tank testing. Computational techniques have become increasingly popular for design and optimization applications in all engineering disciplines. Computational Fluid Dynamics (CFD), is the fastest developing area in marine fluid dynamics as an alternative to model tests. High fidelity CFD methods are capable of modelling breaking waves which is especially crucial for trim optimisation studies where the bulbous bow partially emerges or the transom stern partially immerses. This paper presents a trim optimization study on the Kriso Container Ship (KCS) using computational fluid dynamics (CFD) in conjunction with towing tank tests. A series of resistance tests for various trim angles and speeds were conducted at 1:75 scale at design draft. CFD computations were carried out for the same conditions with the hull both fixed and free to sink and trim. Dynamic sinkage and trim add to the computational cost and thus slow the optimisation process. The results obtained from CFD simulations were in good agreement with the experiments. After validating the applicability of the computational model, the same mesh, boundary conditions and solution techniques were used to obtain resistance values for different trim conditions at different Froude numbers. Both the fixed and free trim/sinkage models could predict the trend of resistance with variation of trim angles; however the fixed model failed to measure the absolute values as accurately as the free model. It was concluded that a fixed CFD model, although computationally faster and cheaper, can find the optimum trim angle but cannot predict the amount of savings with very high accuracy. Results concerning the performance of the vessel at different speeds and trim angles were analysed and optimum trim is suggested.

scholarly journals A Numerical Study of the Impact of Radial Baffles in Solid Bowl Centrifuges Using Computational Fluid Dynamics

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Xiana Romaní Fernández ◽  
Hermann Nirschl
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Multiphase Flow ◽  
Fine Particles ◽  
Numerical Study ◽  
Small Particles ◽  
Sedimentation Behavior ◽  
Computational Fluid Dynamics Cfd ◽  
Separation Equipment ◽  
The Impact

Centrifugal separation equipment, such as solid bowl centrifuges, is used to carry out an effective separation of fine particles from industrial fluids. Knowledge of the streams and sedimentation behavior inside solid bowl centrifuges is necessary to determine the geometry and the process parameters that lead to an optimal performance. Regarding a given industrial centrifuge geometry, a grid was built to calculate numerically the multiphase flow of water, air, and particles with a computational fluid dynamics (CFD) software. The effect of internal radial baffles on the multiphase flow was investigated. The results show that the baffles are helpful for the acceleration of the fluid, but they disturb the axial boundary layer, making it irregular, and originate a secondary circulating flow which hinders the sedimentation of small particles.

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