A Parametric Investigation of Wake Loss Reduction by using Serrated Trailing Edge in a High-speed Compressor Cascade
-
Huaping Liu
,
Feipeng Yu
Abstract
The influence of the serration with different widths, angles and spanwise locations on the wake of a high-speed compressor cascade is parametrically investigated by numerical simulation. The effect mechanisms of the serration on the cascade performance are discussed in detail and the potential at the off-design points is also validated. The results show that the momentum inputted by the serration jet and the fluid exchange induced by the dominant jet vortex could reenergize the low energy corner region and weaken the trailing edge shedding vortex. With the upstream shift of the serration valley, the loss reduction and pressure rise are enhanced due to the strengthened jet and counter-rotating vortex pair, whereas the flow turning is reduced by the decreased camber angle and the enhanced jet deflection. The serration at the blade height corresponding to the core of the low energy fluid could perform better for the loss reduction, whereas the serration close to the endwall could obtain higher pressure rise. For the optimal serration located at 12.5 % blade height with a width of 5 mm and an angle of 45 °, the loss is reduced by 8.9 % and the pressure rise is increased by 2.2 %, with the flow turning slightly reduced by 0.93 °
Funding statement: This work is supported by the National Natural Science Foundation of China (Grant No. 51306042 and No. 51506036).
Conflict of Interest Statement
The authors declare that there is no conflict of interest regarding the publication of this paper
Nomenclature
- B
Axial chord
- c
Blade chord
- Cp
Static pressure coefficient
- CV
Corner vortex
- CSV
Concentrated shedding vortex
- H
Blade span
- h
Spanwise location of serration central line
- H/c
Blade aspect ratio
- h/H
Non-dimensional Spanwise location of serration central line
- HL
High-level loss region
- i
Incidence
- JV
Jet vortex
- LC
Loss generation between the axial section of x/B=50 % and x/B=100 %
- LW
Loss generation between the axial section of x/B=100 % to x/B=150 %
- Ma
Inlet Mach number
- PV
Passage vortex
- t/c
Pitch to chord ratio
- TSV
Trailing edge shedding vortex
- U
Axial velocity component
- V
Pitch-wise velocity component
- VG
Vortex generator
- WV
Wall vortex
- β
Exit flow angle
- βI
Inlet flow angle
- βst
Stagger angle
- λ
Serration width
- λ/H
Non-dimensional Serration width
- φ
Serration angle
- ω
Total pressure loss coefficient
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