Active Flow Control Concepts on a Highly Loaded Subsonic Compressor Cascade: Re´sume´ of Experimental and Numerical Results

Gmelin, Christoph; Zander, Vincent; Hecklau, Martin; Thiele, Frank; Nitsche, W.; Huppertz, André; Swoboda, M.

doi:10.1115/gt2011-46468

Cited by 10 publications

(11 citation statements)

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“…In the current study, a Rolls-Royce Deutschland lowspeed compressor stator cascade 14,22,25 characterized with low aspect ratio and overcritical turning is investigated. The blade cascade is depicted in Figure 1(a).…”

Section: Computational Procedures Cascade and Synthetic Jet Actuatormentioning

confidence: 99%

“…Apart from steady control techniques presented above, unsteady active flow control techniques could improve flow behaviors in the blade passage remarkably with relatively small local energy addition, which would reduce the required jet flow and improve the control efficiency. [13][14][15][16] As an unsteady active flow control technique based on the motion of vortex, synthetic jets possess unique superiority of compact structure, no pipe requirement and easily controlled actuation parameters, which have been widely used in the fields of flow separation control, heat and mass transfer enhancement and noise suppression, etc. 17 The synthetic jet is essentially a zero-net-mass-flux jet.…”

Section: Introductionmentioning

confidence: 99%

“…In recent years, the high integration of the actuator has been achieved with the development of microelectromechanical systems technology, hence the synthetic jet actuator characterized with wide frequency range, high momentum, strong robustness, and low cost is having a promising prospect in real industrial application. Gmelin et al 14 employed both steady and unsteady actuation to control secondary flows in a highly loaded compressor cascade. Results indicated that compared with other flow control techniques which were able to delay flow separation and improve the cascade performance, the synthetic jet actuation appeared to be more efficient, which is consistent with the findings of Zheng et al, 18 Matejka et al, 19 and Traficante et al and De Giorgi et al 20,21 In addition, the control mechanisms of synthetic jets on reducing losses were revealed by De Giorgi et al 21 Using large eddy simulation, they found that the increased values of root-mean-square (RMS) velocity near the actuation slot were related to the enhancement of momentum mixing, which transported kinetic energy from the jet flow to the boundary layer, helping the low energy fluid to overcome severe streamwise adverse pressure gradient.…”

Section: Introductionmentioning

confidence: 99%

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Flow separation control on a highly loaded compressor cascade using endwall synthetic jets

Qin

Song

Wang

et al. 2017

Proceedings of the Institution of Mechanical Engineers, Part G:

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This paper presents flow separation control conducted on a highly loaded compressor stator cascade using endwall synthetic jets. Numerical methods are employed and mechanisms of endwall synthetic jets in improving the cascade performance are discussed in detail. The influence of several actuation parameters is also investigated. Results show that endwall synthetic jets are able to improve the flows in the blade passage significantly, a maximum loss reduction of 21.63% and a pressure rise increment of 5.60% are obtained at design condition. Apart from energizing the low momentum fluid inside endwall boundary layer by streamwise momentum addition, endwall synthetic jets could induce a streamwise jet vortex and impede the transverse movement of endwall boundary layer through upwash and downwash. Hence, at the expense of slightly degraded near-wall flows, the formation and further evolution of passage vortex would be delayed and flows in the midspan region would be improved notably. The effectiveness of endwall synthetic jets relies on the proper selection of actuation position and jet angle. Flow control turns out to be the most efficient when the actuator is positioned at just upstream of corner separation region with a relatively small jet angle, and a large enough injected momentum is also necessary. Additionally, the adaptability of the actuation at off-design conditions is validated in the present study.

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Section: Computational Procedures Cascade and Synthetic Jet Actuatormentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Flow separation control on a highly loaded compressor cascade using endwall synthetic jets

Qin

Song

Wang

et al. 2017

Proceedings of the Institution of Mechanical Engineers, Part G:

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“…Glezer et al [2] conducted the experiment on synthetic jet technology and found that the synthetic jet has great potential for controlling flow separation. Gmelin et al [5] used numerical and experimental methods to conduct the synthetic jet control on a high-loaded low-speed compressor cascade. The numerical simulation and experimental results are in a good agreement.…”

Section: Introductionmentioning

confidence: 99%

Numerical investigation on corner separation control in a linear compressor cascade by synthetic jet

Liu¹,

Wang²,

Huang³

et al. 2020

Proceedings of Global Power &Amp; Propulsion Society

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Corner separation is a kind of three-dimensional separation which occurs commonly in the junction of the endwall and blade corner region of high-loaded compressor. The increases of flow losses and the blockage associated with the corner separation have negative effect on the efficiency and stability of compressor. In this paper the flow control of corner separation by a synthetic jet is numerically investigated with the Reynolds Averaged Navier-Stokes/Large Eddy Simulation (RANS/LES) hybrid method to improve the cascade performance under the design condition. The synthetic jet is mounted on the blade suction side of a subsonic linear compressor cascade using NACA65 blade profiles. The influence of the synthetic jet on the vortex structures and unsteady characteristics in the cascade is investigated. The results indicate that, with the presence of synthetic jet, the passage vortex is weakened, and the corner vortex is receded indirectly. The intensity and range of the concentrated shedding vortex of the suction surface boundary layer are reduced. The total pressure loss coefficient is decreased by 25.8% at the design operating condition. Through calculating the entropy generation rate in the cascade, it is found that the blade profile loss is responsible for the additional flow losses. The synthetic jet significantly reduces the irreversible losses in the blade passage and wake region. From the perspective of the bimodal distributions of corner separation, the parameters increase first and then decrease, and the bimodal points appear in the abrupt velocity zone rather than at the separation points only.

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“…Unsteady excitation showed a great potential in improving cascade performances under appropriate excitation frequencies, amplitudes, and locations, and also there existed a most effective excitation frequency, which was exactly equal to the characteristic frequency of vortex shedding. 12,13 The experimental and numerical investigations were employed by Gmelin et al 14 in a high-loaded compressor cascade with steady jets, pulsed jets, and synthetic jets. For three kinds of flow control configurations, the control effects of flow separations were more distinct when their best excitation locations were selected.…”

Section: Introductionmentioning

confidence: 99%

Flow control using unsteady pulsed holed suction with different excitation models in a highly loaded compressor cascade

Chen

Gong

Wang

2017

Proceedings of the Institution of Mechanical Engineers, Part A:

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Unsteady pulsed holed suction as a new unsteady flow control technique is first proposed. Unsteady excitation models of four different waveforms (Waveforms 1, 2, 3, and 4) based on unsteady pulsed holed suction are investigated to analysis comparatively the control effects of flow separations in a certain highly loaded compressor. Some related unsteady aerodynamic parameters such as excitation frequency and excitation location are studies. The unsteady pulsed holed suctions of the four different modes (Waveforms 1, 2, 3, and 4) all effectively control flow separations. Their optimum frequencies are all an integer multiple of the natural frequency of vortex shedding. And their excitation locations gaining positive effect and optimal excitation locations are both same. The optimal excitation location is near the separation point of upper endwall in unexcited case. But, they show markedly different performances in reducing the total pressure losses. The unsteady pulsed holed suction of Waveform 3 shows greater advantage at different excitation frequencies and excitation locations. The optimum result is obtained by the unsteady pulsed holed suction of Waveform 3. The total pressure loss is reduced by 16.8%. Simultaneously, the unsteady pulsed holed suctions of the four different modes all can provide better effects than the steady constant holed suction in reducing the total pressure loss with the same suction-to-inlet time-averaged suction flow ratio ms. Especially at ms = 0.29%, for the steady constant holed suction, it is too small to effectively control flow separation, and consequently the total pressure loss are increased by 8.3%. However, for the unsteady pulsed holed suctions of Waveforms 2 and 3, the total pressure losses are reduced by 9.1% and 4.3%, respectively.

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Active Flow Control Concepts on a Highly Loaded Subsonic Compressor Cascade: Re´sume´ of Experimental and Numerical Results

Cited by 10 publications

References 0 publications

Flow separation control on a highly loaded compressor cascade using endwall synthetic jets

Flow separation control on a highly loaded compressor cascade using endwall synthetic jets

Numerical investigation on corner separation control in a linear compressor cascade by synthetic jet

Flow control using unsteady pulsed holed suction with different excitation models in a highly loaded compressor cascade

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