Unsteady Laminar Flow through a Curved Duct with Small Curvature

The study of flows and heat transfer in curved ducts and channels has been and continues to be an area of paramount interest of many researchers because of the diversity of their practical applications in fluids engineering, such as in fluid transportation, turbomachinery, refrigeration, air conditioning systems, heat exchangers, ventilators, internal combustion engines and blade-to-blade passages in modern gas turbines. Blood flow in the human and other animals also represents an important application of this subject because of the curvature of many blood vessels, particularly the aorta. The flow through a curved duct shows physically interesting features under the action of the centrifugal force caused by the curvature of the duct. The presence of curvature generates centrifugal forces which act at right angle to the main flow direction and produce secondary flows. In the present dissertation, a numerical study is presented for the unsteady solutions of the thermal flows through a curved square duct for various Dean numbers. Time evolutions of the resistance coefficient are presented for small curvature at the small Grashof number Gr = 100.