Flow control mechanisms of a combined approach using blade slot and vortex generator in compressor cascade

Hu, Junfeng; Wang, Rugen; Huang, Danqin

doi:10.1016/j.ast.2018.04.034

Cited by 45 publications

(20 citation statements)

References 11 publications

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“…17,18 To control the flow within the blade channel, the special slotted blades are often used in the compressor to reduce flow separation on the blade. As proved by Hu et al, 19 the flow separation could be effectively controlled to improve the performance of the compressor by slotted blades, and similar researches were also carried out by Zhou et al 20 and Ghazanfari et al 21 As for centrifugal pumps, effects of slotted blades on the pump performance are also explored. Zhu et al investigated the influence of the gap blades on the cavitation performance, and the gap was placed around the blade leading edge.…”

Section: Introductionmentioning

confidence: 91%

Effects of the staggered blades on unsteady pressure pulsations and flow structures of a centrifugal pump

Zhang

Gao

et al. 2021

Proceedings of the Institution of Mechanical Engineers, Part A:

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Effects of the staggered blades on unsteady pressure pulsations of a centrifugal pump with a specific speed ns=147 are investigated by the numerical simulation method. The obtained results are compared with the original blades. To clarify the resulting effects, eight monitoring points are used to extract pressure signals at three typical working conditions, and component at the blade passing frequency fBPF is emphasized. Results show that the pump efficiency and head will be reduced by the staggered blades, and at the nominal flow rate, the reduction is about 1.5% from comparison with the original blades. For all the eight points, the staggered blades contribute to the reduction of pressure amplitudes at fBPF when the pump works at three flow rates. The averaged reduction is 15.5% at the nominal flow rate. However, the negative effect on the second harmonic of fBPF will be caused by the staggered blades, and the corresponding pressure amplitude will increase at 2fBPF. It means that the pressure pulsation energy will be redistributed among the discrete components in pressure spectrum by the staggered blades. From the TKE distribution, it is found that the TKE values on the blade pressure side will be significantly affected by the staggered blades.

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Section: Introductionmentioning

confidence: 91%

Effects of the staggered blades on unsteady pressure pulsations and flow structures of a centrifugal pump

Zhang

Gao

et al. 2021

Proceedings of the Institution of Mechanical Engineers, Part A:

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“…The increase of efficiency was 1.4% at near stall point along with extension of the stability margin. Hu et al [11][12][13] designed a combined flow control method with the slotted blade and vortex generator. According to comprehensive numerical and experimental investigation of the method on both cascade and compressor, the results could be concluded that separation flow in cascade was reduced obviously and the outlet flow was smoother.…”

Section: Introductionmentioning

confidence: 99%

Influences of slotted blade on performance and flow structure of a transonic axial compressor

Zhang

Gao

et al. 2021

Proceedings of the Institution of Mechanical Engineers, Part A:

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Main reason of compressor instability is boundary layer separation on the surface of blades. As one of flow control methods of the compressor, slotted blade has attracted many researchers’ attention because of its simple geometric structure and remarkable flow control effect. In order to evaluate its availability in the compressor, a type of convergent slot is designed to implement in a single-stage transonic axial compressor. Three configurations, i.e. rotor slot, stator slot and rotor-stator combined slot, are introduced to study the aerodynamic performance of compressor by numerical simulations. Furthermore, flow structures have been analyzed to explain the corresponding mechanism. The results show that overall stability margin of the compressor has been improved by flow control with slotted blade. Behavior of the rotor slot is better than that of the stator slot, but due to mass flow leakage in the slot, peak efficiency and chocking mass flow rate of the compressor are decreased by 1.18% and 3.8% respectively. The low momentum flow on pressure surface is sucked into the jet slot of stator blade, which improves the overall stability margin of 0.63%. The combined scheme with slotted rotor and slotted stator has obtained the best aerodynamic behavior with the increase of the overall stability margin of 2.83%. During the future research, main goal will be improvement of the compressor performance and extension of the mass flow rate range.

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“…Basic design recommendations were extracted from open literature and optimization of a transonic compressor tandem cascade was performed, which resulted in a highly loaded, high efficient tandem compressor cascade and showed a good agreement with the recommended design aspects. Hu et al 13 investigated the flow control of blade slot in a highly loaded compressor cascade, which can be seen as a specific form of tandem cascade. Results showed that the slot produced high-speed jets to reenergize the separation flows on suction side.…”

Section: Introductionmentioning

confidence: 99%

“…Hu et al. 13 investigated the flow control of blade slot in a highly loaded compressor cascade, which can be seen as a specific form of tandem cascade. Results showed that the slot produced high-speed jets to re-energize the separation flows on suction side.…”

Section: Introductionmentioning

confidence: 99%

Flow physics of highly loaded tandem compressor cascade with non-axisymmetric endwall profiling

Cao

Guo

Song

et al. 2020

Proceedings of the Institution of Mechanical Engineers, Part A:

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Tandem configuration is an effective methodology to reduce flow separation on compressor blade suction surface and to improve blade loading. However, in modern highly loaded cases, corner separation remains as its single blade counterpart. In this study, non-axisymmetric endwall profiling (NAEP) was utilized in a highly loaded tandem cascade (diffusion factor D = 0.69), aiming at reducing its severe corner separation and revealing the unique flow mechanism while NAEP is utilized in tandem cascade. NAEP was designed in both forward (F) blade and rare (R) blade separately, and was investigated numerically in tandem environment. Results show that, NAEP in F blade passage can effectively eliminate the corner separation and reduce loss generation, whereas NAEP in R blade passage has no positive effect on corner separation and even promotes loss production. The optimal NAEP approximately removes the corner separation completely, with loss coefficient reducing by as much as 37.8%. The optimal NAEP for the tandem cascade features optimal axial location at the origin of corner separation. There is an optimal NAEP height (0.02 of blade height), under which NAEP can achieve pretty good control effect while the peak of NAEP varies in a large axial location range. In the tandem configuration, it is found that NAEP transfers blade loading from R blade to F blade; the static pressure increases significantly for the entire cascade, but the static pressure distribution of F blade does not exhibit as the design intent of NAEP. In addition, it is interesting to find that the flow turning near endwall reduces after endwall profiling, which is unique in tandem cascade and is contrast to the view on conventional configuration. On the contrary, NAEP in R blade has no influence on the corner separation of the tandem cascade; due to the decrement of cross-passage pressure gradient for R blade, the flow overturning near endwall reduces.

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Flow control mechanisms of a combined approach using blade slot and vortex generator in compressor cascade

Cited by 45 publications

References 11 publications

Effects of the staggered blades on unsteady pressure pulsations and flow structures of a centrifugal pump

Effects of the staggered blades on unsteady pressure pulsations and flow structures of a centrifugal pump

Influences of slotted blade on performance and flow structure of a transonic axial compressor

Flow physics of highly loaded tandem compressor cascade with non-axisymmetric endwall profiling

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