Measurement of eddy diffusivity of momentum in film cooling flows with streamwise injection

Measurements of mean velocity and turbulent shear stress are presented for the mixing region of a film cooling situation in which the coolant is strea mwise injected with an injection angle of 35 deg. Measurements are performe d using triple-sensor anemometry so that all three instantaneous velocity c omponents are documented. The free-stream turbulence intensity level is 12 percent, the ratio of the integral length scale to injection hole diameter is 4.0, the coolant-to-mainstream momentum flux ratio is 1.0, and the densi ty ratio is unity. From these measurements, values for the eddy diffusiviti es of momentum in the lateral and wall-normal directions are calculated. Ad ditionally, calculated values of the ratio of eddy diffusivity in the spanw ise direction to eddy diffusivity in the wall-normal direction are presente d, which provide documentation of the anisotropy of turbulent transport in this film cooling flow.