# Example Poiseuille mdbc

Hello,

I was looking at the example provided in examples/mdbc/02_Poiseuille and specifically the analytical calculator.

There the pressure gradient is taken to be 0.8 and it says the acceleration is 0.8m/s^2. In .xml file the acceleration is also taken as 0.8.

If the acceleration is 0.8m/s2, shouldn't the pressure gradient be 0.8*rho, since when calculation the exact solution the viscosity is taken to be the kinematic viscosity?