scholarly journals Numerical Study of the Air Flow over a NACA 0015 Wind Turbine Airfoil

2018 ◽  
Author(s):  
Houari Ameur ◽  
Karima Boukhadia
Keyword(s):  
Pressure Distribution ◽  
Numerical Study ◽  
Computer Code ◽  
Computational Domain ◽  
Computer Tool ◽  
Wind Turbine Airfoil ◽  
Lift And Drag ◽  
Volume Method ◽  
Icem Cfd ◽  
Naca 0015

A numerical study of the flow over a NACA aerofoil is presented in this paper. The numerical simulations are achieved with the computer code CFX and the computational domain is created by the computer tool ANSYS ICEM CFD. The CFX code is based on the finite volume method to solve the equations of mass, momentum and energy. The purpose of this paper is to determine the pressure distribution, flow patterns and the forces acting on the airfoil. Effects of the attack angle and Reynolds number on the velocity and pressure distribution, on the lift and drag coefficients are also explored.

scholarly journals Numerical study on characteristics of flow and thermal fields around rotating cylinder

10.30544/450 ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 71-86
Author(s):  
Kamel Korib ◽  
Mohamed ROUDANE ◽  
Yacine Khelili
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Numerical Study ◽  
Simple Algorithm ◽  
Rotation Rates ◽  
Rotating Circular Cylinder ◽  
Flow And Heat Transfer ◽  
Lift And Drag ◽  
Energy Equations ◽  
Volume Method

In this paper, a numerical simulation has been performed to study the fluid flow and heat transfer around a rotating circular cylinder over low Reynolds numbers. Here, the Reynolds number is 200, and the values of rotation rates (α) are varied within the range of 0 < α < 6. Two-dimensional and unsteady mass continuity, momentum, and energy equations have been discretized using the finite volume method. SIMPLE algorithm has been applied for solving the pressure linked equations. The effect of rotation rates (α) on fluid flow and heat transfer were investigated numerically. Also, time-averaged (lift and drag coefficients and Nusselt number) results were obtained and compared with the literature data. A good agreement was obtained for both the local and averaged values.

scholarly journals Numerical Study of Wind-Tunnel Wall Effects on Lift and Drag Characteristics of NACA 0012 Airfoil

CFD letters ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 72-82
Author(s):  
Mostafa Abobaker ◽  
Sogair Addeep ◽  
Abdulhafid M. Elfaghi
Keyword(s):  
Wind Tunnel ◽  
Numerical Study ◽  
Published Data ◽  
Computational Domain ◽  
Tunnel Wall ◽  
Ansys Fluent ◽  
Slope Correction ◽  
Lift Curve ◽  
Lift And Drag ◽  
Naca 0012

Possible interference effects of the wind tunnel walls play an important role especially for measurements in closed-wall test sections. In this study, a numerical analysis of two-dimensional subsonic flow over a NACA 0012 airfoil at different computational domain heights, angles of attack from 0o to 10o, and operating Reynolds number of 6×106 is presented. The work highlights the role of computational fluid dynamics (CFD) in the investigation of wind tunnel wall effect on lift curve slope correction factor (Ka). The flow solution is obtained using Ansys Fluent software by solving the steady-state continuity and momentum governing equations combined with turbulence model k-v shear stress transport (SST-K?). The numerical results are validated by comparing with the available experimental measurements. Calculations show that the lift curve slope correction results are very close to the published data.

scholarly journals CONSTRUCTAL DESIGN OF A VORTEX TUBE FOR SEVERAL INLET STAGNATION PRESSURES

2012 ◽  
Vol 11 (1-2) ◽  
pp. 85 ◽  
Author(s):  
C. H. Marques ◽  
L. A. Isoldi ◽  
E. D. Dos Santos ◽  
L. A. O. Rocha
Keyword(s):  
Turbulent Flows ◽  
Degrees Of Freedom ◽  
Vortex Tube ◽  
Numerical Study ◽  
Cylindrical Tube ◽  
Navier Stokes ◽  
Working Fluid ◽  
Computational Domain ◽  
Constructal Design ◽  
Volume Method

The present paper shows a numerical study concerned with the geometrical optimization of a vortex tube device by means of Constructal Design for several inlet stagnation pressures. In the present study, it is evaluated a vortex tube with two-dimensional axisymmetric computational domain with dry air as the working fluid. The compressible and turbulent flows are numerically solved with the commercial CFD package FLUENT, which is based on the Finite Volume Method. The turbulence is tackled with the k-ε model into the Reynolds Averaged Navier-Stokes (RANS) approach. The geometry has one global restriction, the total volume of the cylindrical tube, and four degrees of freedom: d3/D (the ratio between the diameter of the cold outlet and the diameter of the vortex tube), d1/D (the ratio between the diameter of the inlet nozzle and the diameter of the vortex tube), L2/L (the ratio between the length of the hot exit annulus and the length of the vortextube) and D/L (the ratio between the diameter of the vortex tube and its length). The degree of freedom L2/L will be represented here by the cold mass fraction (yc). In the present work it is optimized the degrees of freedom yc and d3/D while the other degrees of freedom and the global restriction are kept fixed. The purpose here is to maximize the amount of energy extracted from the cold region (cooling effect) for several geometries, as well as, investigate the influence of the inlet stagnation pressure over the optimal geometries. Results showed an increase of the twice maximized cooling heat transfer rate of nearly 330 % from 300 kPa to 700 kPa. Moreover, the optimization showed a higher dependence of (d3/D)o for the lower range of inlet pressures, while the optimization is more dependent of yc,oo for higher inlet stagnation pressures.

New Method of Flow Maldistribution Mitigation in Parallel Microchannel Heat Sink

2017 ◽  
Author(s):  
Vikas Yadav ◽  
Ritunesh Kumar
Keyword(s):  
Temperature Distribution ◽  
Heat Sink ◽  
Numerical Study ◽  
Three Dimensional ◽  
Heat Sinks ◽  
Maximum Temperature ◽  
Computational Domain ◽  
Microelectronic Devices ◽  
Volume Method ◽  
Flow Maldistribution

Microchannel heat sinks (MCHS) are explored as integrated cooling option in diversified applications ranging from microelectronic devices to nuclear reactors. Parallel channel MCHS suffers from the problem of flow maldistribution in channels. The phenomenon of flow maldistribution causes undesired effects such as non-uniform temperature distribution, increase in base maximum temperature and drop in MCHS performance. In the present single phase numerical study; flow maldistribution in vertical supply MCHS has been estimated by taking entire heat sink as computational domain. Three-dimensional governing equations for both fluid flow and energy transfer are solved by finite volume method. A novel heat sink design by splitting the inlet flow in two equal parts has been proposed to effectively reduce flow maldistribution problem in MCHS. Results of velocity distribution, temperature distribution of fluid and overall thermal performance of proposed MCHS are compared with the conventional MCHS design. Proposed scheme helps in reducing flow maldistribution problem significantly (∼55%) as compared to conventional MCHS.

Stationary fluid convection modes with a Gaussian viscosity dependence of temterature

2016 ◽  
Vol 11 (2) ◽  
pp. 218-225
Author(s):  
V.S. Kuleshov
Keyword(s):  
Computer Code ◽  
Boussinesq Approximation ◽  
Simple Type ◽  
Transfer Coefficients ◽  
Convective Flows ◽  
Heat Transfer Coefficients ◽  
Fluid Convection ◽  
Flat Cell ◽  
Volume Method ◽  
Viscosity Dependence

The results of a numerical modeling of thermo-gravitational convection of abnormally thermo-viscous fluid in a closed square cavity with two vertical adiabatic walls and two horizontal isothermal walls are presented. A model Newtonian liquid for which the dependence of viscosity on temperature is described by a bell function (Gaussian curve) is considered. The natural convection of inhomogeneous liquid is described by the closed mathematical model based on the continuous mechanics equations written in Oberbeck-Boussinesq approximation, where the fluid density is a linear function of temperature. To simulate the fluid flow dynamics, the modified computer code based on the implicit finite volume method and SIMPLE-type algorithm with the second-order temporal accuracy is realized using multiprocessor technology. The effect of the viscosity abnormality on stationary modes of convective flows are studied, the integral heat transfer coefficients in a flat cell are calculated.

scholarly journals Experimental and numerical study of acoustic pressure distribution in a sonochemical reactor

2021 ◽  
Vol 1809 (1) ◽  
pp. 012025
Author(s):  
M O Kuchinskiy ◽  
T P Lyubimova ◽  
K A Rybkin ◽  
O O Fattalov ◽  
L S Klimenko
Keyword(s):  
Pressure Distribution ◽  
Acoustic Pressure ◽  
Numerical Study

scholarly journals Dynamics of Single Droplet Splashing on Liquid Film by Coupling FVM with VOF

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 841
Author(s):  
Yuzhen Jin ◽  
Huang Zhou ◽  
Linhang Zhu ◽  
Zeqing Li
Keyword(s):  
Liquid Film ◽  
Weber Number ◽  
Stokes Equations ◽  
Numerical Study ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Single Droplet ◽  
Navier Stokes Equations ◽  
Volume Method ◽  
The Relationship

A three-dimensional numerical study of a single droplet splashing vertically on a liquid film is presented. The numerical method is based on the finite volume method (FVM) of Navier–Stokes equations coupled with the volume of fluid (VOF) method, and the adaptive local mesh refinement technology is adopted. It enables the liquid–gas interface to be tracked more accurately, and to be less computationally expensive. The relationship between the diameter of the free rim, the height of the crown with different numbers of collision Weber, and the thickness of the liquid film is explored. The results indicate that the crown height increases as the Weber number increases, and the diameter of the crown rim is inversely proportional to the collision Weber number. It can also be concluded that the dimensionless height of the crown decreases with the increase in the thickness of the dimensionless liquid film, which has little effect on the diameter of the crown rim during its growth.

Numerical study of geometric morphing wings of the 1303 UCAV

2021 ◽  
pp. 1-17
Author(s):  
B. Nugroho ◽  
J. Brett ◽  
B.T. Bleckly ◽  
R.C. Chin
Keyword(s):  
Flight Control ◽  
Numerical Study ◽  
Aerodynamic Characteristics ◽  
Morphing Wing ◽  
Rolling Moment ◽  
Wide Range ◽  
Morphing Wings ◽  
Wing Geometry ◽  
Lift And Drag ◽  
Wing Morphing

ABSTRACT Unmanned Combat Aerial Vehicles (UCAVs) are believed by many to be the future of aerial strike/reconnaissance capability. This belief led to the design of the UCAV 1303 by Boeing Phantom Works and the US Airforce Lab in the late 1990s. Because UCAV 1303 is expected to take on a wide range of mission roles that are risky for human pilots, it needs to be highly adaptable. Geometric morphing can provide such adaptability and allow the UCAV 1303 to optimise its physical feature mid-flight to increase the lift-to-drag ratio, manoeuvrability, cruise distance, flight control, etc. This capability is extremely beneficial since it will enable the UCAV to reconcile conflicting mission requirements (e.g. loiter and dash within the same mission). In this study, we conduct several modifications to the wing geometry of UCAV 1303 via Computational Fluid Dynamics (CFD) to analyse its aerodynamic characteristics produced by a range of different wing geometric morphs. Here we look into two specific geometric morphing wings: linear twists on one of the wings and linear twists at both wings (wash-in and washout). A baseline CFD of the UCAV 1303 without any wing morphing is validated against published wind tunnel data, before proceeding to simulate morphing wing configurations. The results show that geometric morphing wing influences the UCAV-1303 aerodynamic characteristics significantly, improving the coefficient of lift and drag, pitching moment and rolling moment.

The Numerical Analysis of the Velocity and Pressure Distribution of the Oil Film in Heavy Hydrostatic Thrust Bearing

2014 ◽  
Vol 541-542 ◽  
pp. 658-662
Author(s):  
Jian Li ◽  
Yuan Chen ◽  
Yang Chun Yu ◽  
Zhu Xin Tian ◽  
Yu Huang
Keyword(s):  
Mathematical Model ◽  
Numerical Analysis ◽  
Pressure Distribution ◽  
Working Conditions ◽  
Thrust Bearing ◽  
Rotation Speed ◽  
The Other ◽  
Surface Load ◽  
Oil Film ◽  
Volume Method

To study the velocity and pressure distribution of the oil film in a heavy hydrostatic thrust bearing, a mathematical model of the velocity is proposed and the finite volume method (FVM) has been used to simulate the flow field under different working conditions. Some pressure experiments were carried out and the results verified the correctness of the simulation. It is concluded that the pressure distribution varies small under different rotation speed when the surface load on the workbench is constant. But the velocity of the oil film is influenced greatly by the rotation speed. When the rotation speed of the workbench is as quick as enough, the velocity of the oil film on one radial side of the pad will be zero, that is to say the lubrication oil will be drained from the other three sides of the recess.

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