Aerodynamics of a Transitioning Turbine Stator Over a Range of Reynolds Numbers

Abstract

Midspan aerodynamic measurements for a three vane-four passage linear turbine vane cascade are given. The vane axial chord was 4.45cm. Surface pressures and loss coefficients were measured at exit Mach numbers of 0.3, 0.7, and 0.9. Reynolds number was varied by a factor of six at the two highest Mach numbers, and by a factor often at the lowest Mach number. Measurements were made with and without a turbulence grid. Inlet turbulence intensities were less than 1% and greater than 10%. Length scales were also measured. Pressurized air fed the test section, and exited to a low pressure exhaust system. Maximum inlet pressure was two atmospheres. The minimum inlet pressure for an exit Mach number of 0.9 was one-third of an atmosphere, and at a Mach number of 0.3, the minimum pressure was half this value. The purpose of the test was to provide data for verification of turbine vane aerodynamic analyses, especially at low Reynolds numbers. Predictions obtained using a Navier-Stokes analysis with an algebraic turbulence model are also given.

High Intensity, Large Length-Scale Freestream Turbulence Generation in a Transonic Turbine Cascade

“…The initial decrease is due to filling in the wake of the bars, which essentially reduces the effectiveness (or effective bar width) of the grid. This is in agreement with results observed by Boyle [14] where active blowing at low blowing ratios is seen to slightly decrease turbulence intensity.…”

“…This modified grid, operated in passive mode, generated cascade inlet turbulence levels approaching 15%, with an integral length-scale of 2 cm. Blowing was performed with the new grid; however, the turbulence intensity decreased, which is consistent with results reported by Boyle [14]. Blowing at low pressure fills in the wake and thus reduces turbulence intensity.…”

“…Boyle et al [14] produced turbulence using parallel round bars with relatively large flow blockage and the option of active blowing. Turbulence of greater than 10% was produced with approximately 1.5 cm length scale.…”

Numerical Predictions of Stanton Numbers, Skin Friction Coefficients, Aerodynamic Losses, and Reynolds Analogy Behavior for a Transsonic Turbine Vane

“…Arts et al [3] employ measured velocity and convective heat transfer distributions around a twodimensional rotor blade at different Mach numbers, Reynolds numbers, free-stream turbulence intensity levels, and inlet incidence angles to validate Navier-Stokes solvers which are employed for turbomachinery airfoil design and analysis. Boyle et al [4] provide turbine vane aerodynamic test data over a range of Reynolds numbers and exit Mach numbers. Predictions of the vane performance characteristics using two-dimensional Navier-Stokes analysis are included for different levels of mainstream turbulence.…”

Effects of High Intensity, Large-Scale Freestream Combustor Turbulence on Heat Transfer in Transonic Turbine Blades

“…Oldfield (1992, 1996) and the previous work by Holmberg (1996) and Holmberg and Pestian (1996) are the exceptions. Giel, et al (2000) Low speed 0.11 18% Barringer, et al (2002) Low speed 0.43 18% Wang, et al (1998) Low speed -20% Thole, et al (1994) Low speed 0.11 13% Low speed -10% Boyle, et al (1998) Low speed -17% Schauer and Pestian (1996) Low speed -20% Radomsky and Thole (2000) Transonic <0.1 5% Holmberg (1996) Low speed -13% Mehendale and Han (1992) …”