Oscillator fin as a novel heat transfer augmentation device for gas turbine cooling applications

A new concept for enhanced lurbulcni transport of heat in internal coolant passages of gas turbine blades is introduced. The new heat transfer augmentation component called "oscillator Tin" is based on an unsteady How system using the interaction of multiple unsteady jets and wakes generated downstream of a fluidic oscillator. Incompressible, unsteady and two dimensional solutions of Reynolds Averaged Navicr-Stokes equations are obtained both for an oscillator fin and for an equivalent cylindrical pin fin and the results are compared. Preliminary results show that a significant increase in the turbulent kinetic energy level occur in the woke region of the oscillator fin with respect to the cylinder with similar level of aerodynamic penally. The new concept docs not require additional components or power to sustain its oscillations and its manufacturing is as easy as a conventional pin Tin. The present study makes use of an unsteady numerical simulation of mass, momentum, turbulent kinetic energy and dissipation rate conservation equations for flow visualization downstream of the new oscillator fin and an equivalent cylinder. Relative enhancements of turbulent kinciic energy and comparisons of the total pressure field from transient simulations qualitatively suggest that the oscillator fin has excellent potential in enhancing local heat transfer in internal cooling passages without significant aerodynamic penalty.