The Numerical Solution of the Navier-Stokes Equations for Incompressible Turbulent Flow Over Airfoils PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download The Numerical Solution of the Navier-Stokes Equations for Incompressible Turbulent Flow Over Airfoils PDF full book. Access full book title The Numerical Solution of the Navier-Stokes Equations for Incompressible Turbulent Flow Over Airfoils by Harwood A. Hegna. Download full books in PDF and EPUB format.
Author: Harwood A. Hegna Publisher: ISBN: Category : Languages : en Pages : 154
Book Description
Numerical solutions are obtained for two-dimensional incompressible turbulent viscous flow over airfoils of arbitrary geometry. An algebraic eddy viscosity turbulence model based on Prandtl's mixing length theory is modified for separated adverse pressure gradient flows. Finite difference methods for solving the inviscid stream function equation and the incompressible laminar Navier-Stokes equations are used. A finite difference method for solving the Reynolds averaged incompressible turbulent two-dimensional Navier-Stokes equations is employed. The inviscid stream function equation and the Navier-Stokes equations are transformed using a curvilinear transformation. A body-fitted coordinate system with a constant coordinate line defining the airfoil section surface is transformed to a rectangular coordinate system in the transformed or computational plane. An elliptic partial differential Poisson equation for each coordinate is used to generate the coordinate system in the physical plane for arbitrary airfoils. The two-dimensional time dependent Reynolds averaged incompressible Navier-Stokes equations in the primitive variables of velocity and pressure and a Poisson pressure equation are numerically solved. Turbulence is modelled with an adverse pressure gradient eddy viscosity technique. An implicit finite difference method is used to solve the set of transformed partial differential equations. The system of linearized simultaneous difference equations, at each time step, is solved using successive-over-relaxation iteration.
Author: Harwood A. Hegna Publisher: ISBN: Category : Languages : en Pages : 154
Book Description
Numerical solutions are obtained for two-dimensional incompressible turbulent viscous flow over airfoils of arbitrary geometry. An algebraic eddy viscosity turbulence model based on Prandtl's mixing length theory is modified for separated adverse pressure gradient flows. Finite difference methods for solving the inviscid stream function equation and the incompressible laminar Navier-Stokes equations are used. A finite difference method for solving the Reynolds averaged incompressible turbulent two-dimensional Navier-Stokes equations is employed. The inviscid stream function equation and the Navier-Stokes equations are transformed using a curvilinear transformation. A body-fitted coordinate system with a constant coordinate line defining the airfoil section surface is transformed to a rectangular coordinate system in the transformed or computational plane. An elliptic partial differential Poisson equation for each coordinate is used to generate the coordinate system in the physical plane for arbitrary airfoils. The two-dimensional time dependent Reynolds averaged incompressible Navier-Stokes equations in the primitive variables of velocity and pressure and a Poisson pressure equation are numerically solved. Turbulence is modelled with an adverse pressure gradient eddy viscosity technique. An implicit finite difference method is used to solve the set of transformed partial differential equations. The system of linearized simultaneous difference equations, at each time step, is solved using successive-over-relaxation iteration.
Author: Harwood Allan Hegna Publisher: ISBN: Category : Aerofoils Languages : en Pages : 171
Book Description
Numerical solutions are obtained for two-dimensional incompressible turbulent viscous flow over airfoils of arbitrary geometry. A body-fitted coordinate system is numerically transformed to a rectangular grid in the computational plane. The time dependent Reynolds averaged Navier-Stokes equations in the primitive variables of velocity and pressure are used. Turbulence is modelled with an algebraic eddy viscosity technique modified for separated adverse pressure gradient flows. The set of transformed partial differential equations is solved with an implicit finite difference method. Numerical solutions for a NACA 0012 airfoil near stall at a chord Reynolds number of 170,000 are favorably compared with surface pressure and velocity field measurements. A small laminar separation bubble near the suction pressure peak is observed. Computed lift and drag coefficients agree well with experimental values. (Author).
Author: Omer Ali El-Sayed Publisher: ISBN: Category : Languages : en Pages : 256
Book Description
The flow-field around a multi-element airfoil with leading-edge slat and trailing edge flap in landing configuration was performed as well as the prediction of the time dependent flow over a NACA 0012 airfoil. The two dimensional incompressible Navier-Stokes equations with a numerical method based on the pseudo compressibility approach was developed to simulate viscous turbulent flow around single and multi-element airfoils. The algorithm uses upwind-biased scheme of third order accuracy for the calculation of the inviscid fluxes, while a second order central differencing in sued for viscous fluxes, the equations are solved using Lower-Upper Symmetric Gauss Seidel (LU-SGS) schemes. The grids around multi-element airfoil are efficiently generated using a multi-block structure technique. The Baldwin-Lomax algebraic turbulence model is used to consider the effect of turbulence. Computed results for the studied cases were compared with experimental data in terms of surface pressure and lift coefficients which show reasonable agreement.
Author: Zahir U. A. Warsi Publisher: ISBN: Category : Navier-Stokes equations Languages : en Pages : 57
Book Description
Numerical solutions of the two-dimensional averaged Navier-Stokes equations for the prediction of laminar, transitional, and turbulent flow fields around finite bodies of arbitrary shapes have been considered. Numerically generated body-fitted curvilinear coordinates and the relevant metric terms are used to provide the finite-difference solutions of the Navier-Stokes and the equations of turbulent quantities. Complete flow fields, including the boundary layer parameters, are obtained by using the zero, one and two-equations models for Schubauer's elliptical section, NACA663-018 airfoil, and a circular cylinder at free stream Reynolds numbers of 159,000, 1.2 and 1.4 million per foot respectively. In addition, a two-equation model with an algebraic-stress closure has also been developed. (Author).
Author: National Aeronautics and Space Administration (NASA) Publisher: Createspace Independent Publishing Platform ISBN: 9781722672980 Category : Languages : en Pages : 82
Book Description
A new two-dimensional computer code was developed to analyze the viscous flow around unconventional airfoils at various Mach numbers and angles of attack. The Navier-Stokes equations are solved using an implicit, upwind, finite-volume scheme. Both laminar and turbulent flows can be computed. A new nonequilibrium turbulence closure model was developed for computing turbulent flows. This two-layer eddy viscosity model was motivated by the success of the Johnson-King model in separated flow regions. The influence of history effects are described by an ordinary differential equation developed from the turbulent kinetic energy equation. The performance of the present code was evaluated by solving the flow around three airfoils using the Reynolds time-averaged Navier-Stokes equations. Excellent results were obtained for both attached and separated flows about the NACA 0012 airfoil, the RAE 2822 airfoil, and the Integrated Technology A 153W airfoil. Based on the comparison of the numerical solutions with the available experimental data, it is concluded that the present code in conjunction with the new nonequilibrium turbulence model gives excellent results. Ahmed, S. and Tannehill, J. C. Unspecified Center...
Author: Alexander Victor Publisher: ISBN: Category : Languages : en Pages :
Book Description
One of the most important applications of finite difference lies in the field of computational fluid dynamics (CFD). In particular, the solution to the Navier-Stokes equation grants us insight into the behavior of many physical systems. The 2-D and 3-D incompressible Navier-Stokes equation has been studied extensively due to its analogous nature to many practical applications, and several numerical schemes have been developed to provide solutions dedicated to different environmental conditions (such as different Reynolds numbers). This research also covers the assignment of boundary conditions, starting with the simple case of driven cavity flow problem. In addition, several parts of the equations are given implicitly, which requires efficient ways of solving large systems of equations.We also considered numerical solution methods for the incompressible Navier-Stokes equations discretized on staggered grids in general coordinates. Numerical experiments are carried out on a vector computer. Robustness and efficiency of these methods are studied. It appears that good methods result from suitable combinations of multigrid methods.Numerically solving the incompressible Navier-Stokes equations is known to be time-consuming and expensive; hence this research presents some MATLAB codes for obtaining numerical solution of the Navier-Stokes equations for incompressible flow through flow cavities, using method of lines, in three-dimensional space (3-D). The code treats the laminar flow over a two-dimensional backward-facing step, and the results of the computations over the backward-facing step are in excellent agreement with experimental results.
Author: Harwood A. Hegna
Author: Harwood A. Hegna
Author: Harwood Allan Hegna
Author: David Seitz Thompson
Author: Omer Ali El-Sayed
Author: Vithalbhai Ambalal Patel
Author: Zahir U. A. Warsi
Author: Stuart Eames Rogers
Author: National Aeronautics and Space Administration (NASA)
Author: Alexander Victor
Author: