FLOW VISUALIZATION AROUND A NON -CIRCULAR TUBE

The flow behavior around a cam shaped tube in a cross flow has been investigated experimentally using flow visualization and pressure distribution measurements. The range of attack angle and Reynolds number based on an equivalent circular diameter are within 0 a 360° and 2x10^4(Re(eq) (3.4xl0^4, respectively. The pressure drag features are clarified in relation to the flow eqbehavior around the tube. It is found that the highest pressure drag coefficient occurs at a = 90° and 270° over the whole range of Reynolds number. Results show that the pressure drag coefficient of the cam -shaped tube is lower than that of a circular tube with the same surface area for more of the attack angles.