University of Texas, Austin
Experience
Aero/thermal studies turbine engine turbine sections. A wide range of studies have been completed in the area of turbine airfoil film cooling. Experimental studies include vane and blade leading edges, vane pressure and suction sides, and full coverage configurations. Special facilities are used to incorporate realistic airfoil geometries and high mainstream turbulence. Measurements include adiabatic effectiveness, heat transfer coefficients, thermal fields, and velocity fields for two-dimensional and three-dimensional regions. Computational studies have focused on the development of the TEXTAN CFD code for rapid analysis of the thermal fields associated with turbine airfoils.
Interest
Recent areas of interest include studies of conjugate heat transfer using models constructed of high conductivity materials. We are also involved in studies of roughness effects and partial hole blockage effects on film cooling performance.
Facility Information
The primary facilities for gas turbine aero/thermal research are two wind tunnels that have been specially modified to incorporate models of turbine vanes and blades. Large scale models are used in both facilities to good spatial resolution of the flow and thermal fields on the scale of the cooling holes used in film cooling. These facilities incorporate secondary flow systems that are cryogenically cooled to allow coolant flows to be cooled to an absolute temperature that is a factor of two smaller than the mainstream temperature. This enables film cooling studies using realistic density ratios for the coolant. The wind tunnels also incorporate free stream turbulence generators that allow mainstream turbulence as high as 20% to be used in experiments. One of the wind tunnels also incorporates a hot streak generator that allows a simulated hot streak to be positioned at varying pitch positions relative to the test vane.
Essentially adiabatic test models are used in conjunction with IR camera surface temperature measurement to obtain adiabatic effectiveness distributions. Heat transfer coefficient measurements are accomplished with constant heat flux surface foils. Velocity field measurements are made with a three-component laser Doppler velocimeter system which was specially designed for near wall measurements around the vane leading edge. Thermal field measurements are made using a miniature thermocouple rake manufactured in our lab. |