Details
| Original language | English |
|---|---|
| Article number | 091001 |
| Journal | Journal of Engineering for Gas Turbines and Power |
| Volume | 144 |
| Issue number | 9 |
| Early online date | 21 Jul 2022 |
| Publication status | Published - 1 Sept 2022 |
Abstract
The influences of axial-slot casing treatment (ASCT) on the performance and unsteady tip region flow are experimentally and numerically investigated in a highly-loaded mixed-flow compressor. The total pressure ratio, stall margin, and efficiency of the compressor are improved with ASCT. Static wall pressure was measured using unsteady pressure taps installed on the casing to identify the stall inception and resolve the tip region flow. The compressor stalls through spike-stall inception with the spillage of tip leakage flow (TLF). FFT analysis of dynamic pressure data shows that unsteady tip clearance flow (TCF) characterized by a frequency band of 0.4-0.6 blade passing frequency exists for both cases with and without ASCT. The addition of ASCT alleviates fluctuating amplitude of TCF in the blade passage but enhances oscillating strength of the main flow located upstream of blade leading-edge. Time-averaged solutions of unsteady simulations indicate that ASCT suppresses the spillage of TLF through suction and injection effects. However, flow separation located downstream of slots is enlarged by ASCT, which is attributed to the increased blade tip load. To reveal the underlying mechanisms, the tip flow field was further studied at various time instants. The fluids with high enthalpy are injected from slots and then divided into two parts by the rotor blade. One part of the fluids attaches on blade pressure side causing the local high static pressure spot, which leads to the increment of pressure loading at blade tip. The other part interacts with TLF periodically, thus pushing it into passage and delaying rotating stall.
ASJC Scopus subject areas
- Energy(all)
- Nuclear Energy and Engineering
- Energy(all)
- Fuel Technology
- Engineering(all)
- Aerospace Engineering
- Energy(all)
- Energy Engineering and Power Technology
- Engineering(all)
- Mechanical Engineering
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In: Journal of Engineering for Gas Turbines and Power, Vol. 144, No. 9, 091001, 01.09.2022.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Unsteady Interaction Mechanisms of Axial-Slot Casing Treatment With Tip Region Flow in a Highly-Loaded Mixed-Flow Compressor
AU - Du, Juan
AU - Qiu, Jiahui
AU - Zhang, Qianfeng
AU - Ba, Dun
AU - Maroldt, Niklas
AU - Seume, Joerg R.
N1 - Funding Information: • National Natural Science Foundation of China (Funder ID: 10.13039/501100001809). • National Science and Technology Major Project (No. 2017-II-0004-0017; Funder ID: 10.13039/501100018537). The authors are grateful for the support of National Natural Science Foundation of China for the grant with Project No. 51922098, and the National Science and Technology Major Project (2017-II-0004-0017). The authors would also like to thank the German Research Foundation (DFG) for supporting the experiments as part of the Collaborative Research Centre 880 (Sonder-forschungsbereich SFB 880, Teilprojekt B4).
PY - 2022/9/1
Y1 - 2022/9/1
N2 - The influences of axial-slot casing treatment (ASCT) on the performance and unsteady tip region flow are experimentally and numerically investigated in a highly-loaded mixed-flow compressor. The total pressure ratio, stall margin, and efficiency of the compressor are improved with ASCT. Static wall pressure was measured using unsteady pressure taps installed on the casing to identify the stall inception and resolve the tip region flow. The compressor stalls through spike-stall inception with the spillage of tip leakage flow (TLF). FFT analysis of dynamic pressure data shows that unsteady tip clearance flow (TCF) characterized by a frequency band of 0.4-0.6 blade passing frequency exists for both cases with and without ASCT. The addition of ASCT alleviates fluctuating amplitude of TCF in the blade passage but enhances oscillating strength of the main flow located upstream of blade leading-edge. Time-averaged solutions of unsteady simulations indicate that ASCT suppresses the spillage of TLF through suction and injection effects. However, flow separation located downstream of slots is enlarged by ASCT, which is attributed to the increased blade tip load. To reveal the underlying mechanisms, the tip flow field was further studied at various time instants. The fluids with high enthalpy are injected from slots and then divided into two parts by the rotor blade. One part of the fluids attaches on blade pressure side causing the local high static pressure spot, which leads to the increment of pressure loading at blade tip. The other part interacts with TLF periodically, thus pushing it into passage and delaying rotating stall.
AB - The influences of axial-slot casing treatment (ASCT) on the performance and unsteady tip region flow are experimentally and numerically investigated in a highly-loaded mixed-flow compressor. The total pressure ratio, stall margin, and efficiency of the compressor are improved with ASCT. Static wall pressure was measured using unsteady pressure taps installed on the casing to identify the stall inception and resolve the tip region flow. The compressor stalls through spike-stall inception with the spillage of tip leakage flow (TLF). FFT analysis of dynamic pressure data shows that unsteady tip clearance flow (TCF) characterized by a frequency band of 0.4-0.6 blade passing frequency exists for both cases with and without ASCT. The addition of ASCT alleviates fluctuating amplitude of TCF in the blade passage but enhances oscillating strength of the main flow located upstream of blade leading-edge. Time-averaged solutions of unsteady simulations indicate that ASCT suppresses the spillage of TLF through suction and injection effects. However, flow separation located downstream of slots is enlarged by ASCT, which is attributed to the increased blade tip load. To reveal the underlying mechanisms, the tip flow field was further studied at various time instants. The fluids with high enthalpy are injected from slots and then divided into two parts by the rotor blade. One part of the fluids attaches on blade pressure side causing the local high static pressure spot, which leads to the increment of pressure loading at blade tip. The other part interacts with TLF periodically, thus pushing it into passage and delaying rotating stall.
UR - http://www.scopus.com/inward/record.url?scp=85135760646&partnerID=8YFLogxK
U2 - 10.1115/1.4054965
DO - 10.1115/1.4054965
M3 - Article
AN - SCOPUS:85135760646
VL - 144
JO - Journal of Engineering for Gas Turbines and Power
JF - Journal of Engineering for Gas Turbines and Power
SN - 0742-4795
IS - 9
M1 - 091001
ER -