Theoretical study of the flow in a rotating duct. Experimental study through flow visualization in a curved duct

An experimental and theoretical study of heat transfer and flow in a rotating duct is under development. The duct simulates an internal cooling passage of the blade of a turbine rotor. It was experimentally demonstrated that the rotational velocity causes an increase in thermal exchange by convection in the duct. This phenomenon is explained by secondary flows due to Coriolis force. The theoretical aspect of the work involves the solution of the Navier-Stokes equations in three dimensions. For both laminar and turbulent flows, the results obtained demonstrate the significance of secondary structures (having both two and four vortices). Also, by using a rotation-curvature analogy, visualization of the flow with air or hydrogen bubbles in a water duct gives rise to the same flow structures.