APMA 2580

Multiscale Computational Fluid Dynamics

Instructor: Professor George Karniadakis

Homework #5



Consider the linear advection equation

\begin{displaymath}\frac{\partial \Theta}{\partial t} + \frac{\partial \Theta}{\partial x} = 0\end{displaymath}

where $x \in [0,10]$ with periodic boundary conditions.

Consider also two different initial conditions

\begin{eqnarray*}\mbox{{\rm (a)}}\;\;\;\; \Theta_0 (x,0) & = & \sin (2\pi x)\\ 
...
...1, x\in [1,2]\\
0, \mbox{{\rm elsewhere}}\end{array}\right .
\end{eqnarray*}




Compute the solution on a 128-point mesh for both initial conditions and for CFL = 0.8. Compare the first- and second-order upwind schemes versus the Lax-Wendroff scheme after 100 time steps and after 10,000 time steps.