# Decay of sinusoidal velocity wave (kolmogorov flow)

1. May 2, 2015

### OldStudent0382

1. The problem statement, all variables and given/known data
Find the velocity field $u(x,t)$

2. Relevant equations
$\rho = constant$
$u(0,t)=0$
$u(0,L)=0$

$\frac{\partial u}{\partial t} = \nu \frac{\partial ^{2}u}{\partial x^{2}}$

$u(x,0)=U_{o}[sin(\frac{3\pi x}{L})+0.7sin(\frac{9\pi x}{L})]$

3. The attempt at a solution

I have absolutely no idea how to start this problem (again) and I'm embarrassed to admit that I've been looking at it and searching for two hours -- and I have nothing to show for it.