Is there a good explanation why the pressure becomes lower on the narrow part of the venturi pipe? I'm not interested in the newton explanation or pressure differences explanation. I want to understand how the impulses on the walls of pipe's narrow part becomes less than that of wider tube. If pressure is about molecules colliding the walls, there has to be an explanation.
I only have one guess: I suspect that it is about 'nearly' incompressible fluid and the 'nearly' part creates a big difference in the number of collisions per unit time.