Showing papers by "Terrence W. Simon published in 1999"
TL;DR: In this article, the effects of hole length-to-diameter ratio variations on discharge coefficients were investigated for several film cooling configurations having hole length to diameter ratios of 2.3, 4.6, 6.6 and 7.0.
Abstract: Measurements of discharge coefficients for several film cooling configurations having hole length-to-diameter ratios of 2.3, 4.6, 6.6, and 7.0 are presented. Recently, it was documented that the velocity distributions over the hole exit plane vary significantly with changes in hole length-to-diameter ratio. This paper documents the effects of such variations on coolant discharge coefficients. Due to the short holes, injection in engines is with a substantial amount of coolant departing the upstream portions of the hole exit plane. This results in a higher rate of momentum exchange with the free stream at that location than for longer holes, which permits more uniform exit flows. Discharge coefficient measurements are discussed in terms of this distribution of velocity. This paper also documents the effects of the hole supply plenum geometry on discharge coefficients. When the coolant flow is delivered to the holes with significant momentum either in the direction of the free stream or opposite to that direction, significant changes in discharge coefficient values are observed.
29 citations
TL;DR: In this paper, the mixing region of a film cooling situation was measured using triple-sensor anemometry, and the free-stream turbulence intensity level is 12 percent, the ratio of integral length scale to injection hole diameter is 4.0, the coolant-to-mainstream momentum flux ratio is 1.0 and the density ratio is unity.
Abstract: Measurements of mean velocity and turbulent shear stress are presented for the mixing region of a film cooling situation in which the coolant is streamwise injected with an injection angle of 35 deg. Measurements are performed using triple-sensor anemometry so that all three instantaneous velocity components 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 density ratio is unity. From these measurements, values for the eddy diffusivities of momentum in the lateral and wall-normal directions are calculated. Additionally, calculated values of the ratio of eddy diffusivity in the spanwise direction to eddy diffusivity in the wall-normal direction are presented, which provide documentation of the anisotropy of turbulent transport in this film cooling flow.
23 citations
22 citations