2. The pressure drop, \( \Delta p \), for incompressible turbulent flow in a horizontal round pipe of diameter \( D \) can be written in functional form as \[ \Delta p = F(V, D, l, \varepsilon, \mu, \rho) \] where \( V \) is the average velocity, \( l \) is the pipe length, \( \varepsilon \) is a measure of the roughness of the pipe wall, \( \rho \) and \( \mu \) are fluid density and viscosity, respectively. Find a non-dimensional relationship for \( \Delta p \). (use \( \rho \), \( V \), \( D \) as repeating variables) (20分)