Numerical Investigation of Wake Effect for High Lift Low Pressure Turbine Blades
Abstract
Highly loaded low pressure turbine (LPT) blades offer opportunities for lower costs and higher performance but suffer from large endwall losses. During the design of new LPT blades, the interaction of the stator wakes with the rotor blades is often neglected. While the wake effect on the mid span performance of LPT blades has been investigated in great detail, little is known about the effect on the endwall flow. For the vast majority of the past research, two dimensional bar wake generators were considered which do not faithfully reproduce the secondary flow and the endwall flow structures. The objective of the proposed research is to (1) develop a detailed understanding of the impact of unsteady wakes on the endwall flow physics and endwall losses and (2) to determine if the wake effect allows for an increase of the blade loading without negatively affecting the endwall losses. To reach the objective, a combined investigative approach of high fidelity simulations and advanced data analyses will be employed. For the simulations, both a bar wake generator and a stator vane will be considered. By exchanging one with the other, the effect of the upstream endwall flow structures on the downstream endwall flow physics can be determined. Particular attention will be paid to the effect of the wakes on the bimodal behavior of the turbulent junction flow, the bursting of the passage vortex, and the suction surface corner separation. The proposed research will make a fundamental contribution to the physical understanding of the highly complex flow through high lift LPT passages. It will also provide a basis for the development of models that accurately predict the endwall losses. Such models are needed for the design of new LPT blades which will ultimately increase overall engine performance and efficiency and-or reduce the engine parts count and maintenance costs.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 14, 2022
- Source ID
- FA95501910080
Entities
People
- Andreas Gross
Organizations
- Air Force Office of Scientific Research
- New Mexico State University
- United States Air Force