How Can I Solve the Orr-Sommerfeld Equation Using Finite Difference Methods?

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In summary, to solve the Orr–Sommerfeld equation for plane Couette flow using numerical methods, you can use a finite difference method and an iterative approach such as the Gauss–Seidel method. References for this approach can be found in the literature, such as the ones listed above.
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URIA
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I trying to solve the orr sommerfeld diff equation using numerical methods. the best candidate in my point of view is a finite difference. can someone help with this?
Much appreciated
Uria
Hy
I trying to solve the orr sommerfeld diff equation (plane Couette flow case) using numerical methods. the best candidate in my point of view is a finite difference. can someone help with this?
Much appreciated
Uria
 
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Ra'ananYou can try using a finite difference method to solve the Orr–Sommerfeld equation. You can start by discretizing the equation with the central difference scheme and then use an iterative approach such as the Gauss–Seidel method to solve the resulting system of equations. This approach has been used in the past to solve this type of equation numerically. You can find more information about this in the following references:1. F. Hussain, “Numerical Solutions of the Orr-Sommerfeld Equation for Plane Couette Flow,” Journal of Computational Physics, vol. 14, no. 1, pp. 65–76, 1974.2. J. P. Verboncoeur, “A Numerical Method for the Solution of the Orr-Sommerfeld Equation in Plane Couette Flow,” AIAA Journal, vol. 31, no. 3, pp. 513–515, 1993.3. M. R. Visbal, “Numerical Solution of the Orr-Sommerfeld Equation in Plane Couette Flow Using Finite Difference Method,” International Journal of Numerical Methods in Fluids, vol. 23, no. 8, pp. 783–796, 1997.
 

FAQ: How Can I Solve the Orr-Sommerfeld Equation Using Finite Difference Methods?

What is the Orr-Sommerfeld equation?

The Orr-Sommerfeld equation is a fourth-order linear differential equation used in fluid dynamics to describe the stability of viscous flow between parallel plates. It arises from the linearization of the Navier-Stokes equations and is used to determine the growth rate of small disturbances in a laminar flow, which can indicate the onset of turbulence.

What are the boundary conditions for the Orr-Sommerfeld equation?

The boundary conditions for the Orr-Sommerfeld equation typically require that the velocity perturbations and their first derivatives vanish at the boundaries of the flow domain. For flow between parallel plates, this means the perturbations must be zero at the walls (y = ±h for a channel of height 2h).

How is the Orr-Sommerfeld equation derived?

The Orr-Sommerfeld equation is derived by linearizing the Navier-Stokes equations around a base laminar flow profile and then applying a normal mode decomposition to the perturbations. This results in a partial differential equation in terms of the streamfunction, which can be further simplified to the fourth-order Orr-Sommerfeld equation.

What numerical methods are used to solve the Orr-Sommerfeld equation?

Numerical methods commonly used to solve the Orr-Sommerfeld equation include spectral methods, such as Chebyshev and Fourier spectral methods, finite difference methods, and shooting methods. These techniques discretize the equation and solve the resulting eigenvalue problem to determine the stability characteristics of the flow.

What is the significance of the Orr-Sommerfeld equation in fluid dynamics?

The Orr-Sommerfeld equation is significant in fluid dynamics because it provides a theoretical framework for understanding the stability of laminar flows and predicting the transition to turbulence. It helps in identifying critical Reynolds numbers and the nature of instabilities that can lead to turbulent flow, which is essential for various engineering applications and understanding natural fluid systems.

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