Hello, So I was reading wikipedia the other day, as I do from time to time. I came across a rather interesting sample problem posed in the article, but seeing as Wikipedia is horrible in some of their physics articles on explaining whats the hell they're doing, I became lost. Here is the problem, I'll be using cylindrical coordinates for simplicity here (r,z,Theta). Suppose we have two discs of equal radius. Disc one is placed at z = +h, and disc two is placed at z = -h. Let's assume that the flow is going to be purely radial, so the only non zero velocity component is the radial velocity component. The fluid that will be flowing is in-compressible, viscous, and newtonian. Following the no-slip condition, we demand that the radial velocity component go to zero when Z = +h and when Z = -h. The mass continuity equation simplifies to d/dr(r*V) = 0, where r is the radial coordinate and V is the radial velocity component. To satisfy this I assume the form V(r,z) = F(z)/r. Plugging this guess into the continuity equation we find that mass continuity is satisfied given V(r,z) = F(z)/r. Using this ansantz we can simplify the momentum equations into the following form. dP/dr = p*F(z)^2/r^3 + u/r*d^2(F(z))/dz^2, or r*dP/dr = p*(F/R)^2 + u*d/dz(dF/dz). According to wikipedia, we should somehow be able to get this into the form F''(z) + R*F^2 = -1, F(-1) = 0, F(1) = 0, where R is the reynolds number in the flow. I'm struggling to see how they manage to deal with the pressure term in the momentum equations that I derived. Here is the link to the actual wikipedia article : https://en.wikipedia.org/wiki/Navier–Stokes_equations#Application_to_specific_problems The problem I'm talking about is problem b.) in the "applications to specific problems" sections. Thanks for your help PS: sorry about not having the equations in latex. I've not learned how to use latex yet. Thanks for getting through them and trying to decipher them.