Problem

Now solve the convection-diffusion equation, hej

$$\begin{array}{rcl} b \cdot \nabla u - \nabla \cdot (a \nab... ...=& \gamma (u - g_D) + g_N \quad \mbox{on } \Gamma, \end{array}$$ (5)

with the same boundary conditions as in the previous problem, $a=1$, and the convection given by $b = (20,0)$, corresponding to a flow from left to the right in the domain.

Check your answer: Plot your solution using the $\texttt{pdesurf}$ command and compare your solution to Figure 3.

Figure 3: A plot of the solution for Problem 3.