Abstract
The full three-dimensional viscous numerical simulation is employed to analyze and compare the interaction phenomena of the unsteady flow field at two axial clearances in an axial-flow turbine stage and then the mechanism of the unsteady loss fluctuation is adopted to describe the reason of entropy fluctuation. The results indicate that when the axial clearance is doubled, the potential interaction changes significantly at the entire stator and the leading edge of the rotor, and the fluctuation amplitude of wall static pressure decreases by about 80% and 60% , respectively. The descending of the potential interaction strength is much faster than that of the negative jet. When the negative jet arrives at the trailing edge of the rotor suction side, the repression effect on the flow separation will occur, resulting in a new triggering mechanism of the calming effect. In addition, the coupling relation between static pressure and entropy in the boundary layer flow of the stator suction side is built by a dissipation function, and a method to analyze the loss fluctuation in the unsteady flow field is developed.
| Original language | English |
|---|---|
| Pages (from-to) | 9-13 |
| Number of pages | 5 |
| Journal | Hsi-An Chiao Tung Ta Hsueh/Journal of Xi'an Jiaotong University |
| Volume | 43 |
| Issue number | 9 |
| State | Published - Sep 2009 |
Keywords
- Axial clearance
- Negative jet
- Numerical simulation
- Turbine stage
- Unsteady