So assume a pressure-driven, incompressible, and steady flow in $x$-direction between 2 inf. fixed surfaces.
Why should the partial derivative $dP/dx$$\frac{\partial P}{\partial x}$ in the Navier-Stoke eqnStokes Eqn. be constant?
My understanding is that:
- not 0, since it's driving the flow
- constant to, so there is no accelacceleration (steady)
But howwhy is it that a constant dP/dx$\frac{\partial P}{\partial x}$ maintains the velocity?
Wouldn't the pressure difference b/t$\frac{dp}{dt}$ at each $x$ point act a force on the flow, and thus accelerate the flow?