66The fluid particles when bending round the corner need some centripetal acceleration towards the center of curvature. In this case the force on the particles need to towards the center which would lie roughly on the line going from 1 to 2 and extended. Accordingly on a fluid particle somewhere between 1 and 2 a net force in the direction from 1 to 2 must act. This means that the pressure at 1 must be greater than that at 2 and accordingly the velocity at 2 must be greater than that at 1.
