Numerical Investigation of Wake Effect for High-Lift Low-Pressure Turbine Blades
Abstract
In low-pressure turbine linear cascade experiments, upstream stator vanes are often modeled by moving bar wake generators. The wake effect of a stator and a bar wake generator on the flow through a rotor with front-loaded high-lift blades were investigated and compared. Implicit large-eddy simulations were performed of the flow through a full turbine cascade withL2F airfoils (for both the stator vanes and rotor blades) as well as of the flow through a linear cascade with L2F blades and moving bar wake generator. The chord-based Reynolds number for the simulations was 50,000 and 100,000. The L2F generates pronounced end wall structures that clearly differentiate the resulting wake flow from that obtained with the bar wake generator. Instantaneous flow visualizations reveal a periodic suppression of the rotor blade suction-side separation for both cases. For the bar wake generator, the wakes are wider and the wake effect is spread out over a larger portion of the wake shedding period. With upstream stator vanes, the rotor blade passage vortex and suction-side corner separation are suppressed. This suggests that for front-loaded high-lift airfoils, bar wake generators can accurately model the effect of the two-dimensional wake component. The stator near-wall structures appear to be chiefly responsible for the suppression of the passage vortex and corner separation. This effect is not captured by the bar wake generator
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 25, 2022
- Accession Number
- AD1230452
Entities
People
- Andreas Gross
Organizations
- New Mexico State University