Pressure loss through sharp 180 deg turns in smooth rectangular channels

Measured pressure distributions, pressure loss coefficients, and surface streamline visualizations are presented for 180-deg turns in smooth, rectangular cross-section channels. The flow geometry models situations that exist in multipass internal cooling of gas turbine engine airfoils. The turn geometry is characterized by parameters that include the ratio of upstream and downstream channel widths, the nondimensional channel depth, the nondimensional clearance height at the tip of the turn, and the nondimensional corner fillet radius. The present results cover a range of combinations of geometry parameters and Reynolds numbers to aid in prediction of coolant flow rates in present and future cooled airfoil designs.