(N/A) Turbulent flow is a type of fluid flow characterized by chaotic, irregular, and unsteady motion of fluid particles. It occurs when the flow velocity exceeds a critical value, causing the Reynolds number to be high $ (Re > 4000) $. In this flow, the velocity at any point changes continuously in both magnitude and direction, leading to the formation of eddies and vortices.
Illustrations of turbulent flow:
$ (i) $ Sea currents.
$ (ii) $ Smoke rising from a burning fire.
$ (iii) $ The twinkling of stars due to turbulence in the Earth's atmosphere.
$ (iv) $ The flow of water around the hull of a moving boat and the air flow around aircraft wing tips.