Application of Stall Warning Approach with Stall Precursor-Suppressed Casing Treatment on a Two-Stage Compressor

A further investigation of an acoustic theory-based stall-warning approach is presented in this paper, which contains the basis of this approach and an application on a low-speed compressor (LSC) with a stabilization system. In the present work, this stall-warning approach is first explained through a numerical simulation in which the periodicity of pressure signals is analyzed, and then application experiments of this approach are actualized on a LSC with a stall precursor-suppressed (SPS) casing treatment (CT) as a stabilization system. For this stall-warning approach, a parameter named Rc is calculated through pressure signals of compressor to evaluate the periodicity of pressure signal, and statistical estimates are implemented on Rc so that the probabilities for Rc less than a threshold Rcth can be used as a criterion for stall warning. The numerical and experimental results both show that the signal resolution is determined by the sensor position, the prestall signal amplitude decreases rapidly with the increase of the distance between sensor and blades. Results also show that the probability increases significantly when the operating point is nearing the stall boundary. And at the same operating point, the probability value of Rc will decrease when the SPS CT is engaged. Through this stall-warning approach, a stabilization system based on SPS CT can be activated when the stall margin needs to be extended.

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Stall Warning Approach With Application to Stall Precursor-Suppressed Casing Treatment

Volume 2D: Turbomachinery ◽

10.1115/gt2016-58172 ◽

2016 ◽

Cited By ~ 4

Author(s):

Li Fanyu ◽

Li Jun ◽

Dong Xu ◽

Sun Dakun ◽

Sun Xiaofeng

Keyword(s):

Pressure Sensor ◽

Dynamic Pressure ◽

Leading Edge ◽

Warning Signal ◽

Stall Margin ◽

Low Speed ◽

Casing Treatment ◽

Statistical Estimates ◽

Stall Warning ◽

Stall Precursor

The present work develops a stall warning approach with application to a stall enhancement system. This technique is proposed on the basis of the periodicity of pressure signals sampled by the dynamic pressure sensor which is located on the casing wall at the rotor leading edge. A parameter called Rc, defined to evaluate this periodicity, is calculated by pressure signals within 1 blade pitches in the current one and previous one shaft period. Statistical estimates are implemented on Rc within statistical windows which move with sampling. The probabilities of Rc less than a threshold Rcth are calculated and used as a criterion for stall warning. Experiments are carried out on a low speed compressor with a stall precursor-suppressed (SPS) casing treatment, an efficient stall enhancement system. Results show that the probability increases significantly when the stall boundary is approached. At the same work point, the value of probability will decrease when the SPS casing treatment is turned on. This approach successfully generates a stall warning signal and then triggers the SPS casing treatment when the stall margin needs to be extended.

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Effects of Rotating Inlet Distortion on Two-Stage Compressor Stability With Stall Precursor-Suppressed Casing Treatment

Volume 2A: Turbomachinery ◽

10.1115/gt2018-76701 ◽

2018 ◽

Author(s):

Dakun Sun ◽

Jia Li ◽

Xu Dong ◽

Benhao Gu ◽

Xiaofeng Sun

Keyword(s):

Wire Mesh ◽

Two Stage ◽

Stall Margin ◽

Casing Treatment ◽

Inlet Distortion ◽

Compressor Rotor ◽

Mesh Screen ◽

Stall Margin Improvement ◽

Stall Precursor ◽

Different Levels

Experimental research about rotating inlet distortion is carried out on a two-stage compressor with emphasis on the compressor stability as well as the stall margin improvement with a kind of stall precursor-suppressed (SPS) casing treatment in this paper. The wire mesh screen is placed at the upstream of the IGV and can rotate at various speeds in co- and counter-direction of the compressor rotor to simulate the rotating inlet distortion in different levels. The results show that the rotating inlet distortion can deteriorate the compressor stall margin and the SPS casing treatment can extend the compressor stall margin (1.95%–7.90%) without additional efficiency loss. The pre-stall behavior of compressor is also analyzed to uncover the mechanism of the stall margin improvement with such casing treatment. Results show that casing treatment of this configuration can weaken the unsteady disturbances in compression system.

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Stall Warning Using the Rotor Tip Pressure in a Transonic Axial Compressor With Circumferential Grooves

Volume 2A: Turbomachinery ◽

10.1115/gt2018-76301 ◽

2018 ◽

Author(s):

Byeung Jun Lim ◽

Tae Choon Park ◽

Young Seok Kang

Keyword(s):

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Axial Compressor ◽

Rotating Stall ◽

Single Stage ◽

Stall Inception ◽

Casing Treatment ◽

Stall Warning ◽

Transonic Axial Compressor

In this study, characteristics of stall inception in a single-stage transonic axial compressor with circumferential grooves casing treatment were investigated experimentally. Additionally, the characteristic of increasing irregularity in the pressure inside circumferential grooves as the compressor approaches the stall limit was applied to the stall warning method. Spike-type rotating stall was observed in the single-stage transonic axial compressor with smooth casing. When circumferential grooves were applied, the stall inception was suppressed and the operating point of the compressor moved to lower flow rate than the stall limit. A spike-like disturbance was developed into a rotating stall cell and then the Helmholtz perturbation was overlapped on it at N = 80%. At N = 70 %, the Helmholtz perturbation was observed first and the amplitude of the wave gradually increased as mass flow rate decreased. At N = 60%, spike type stall inceptions were observed intermittently and then developed into continuous rotating stall at lower mass flow rate. Pressure measured at the bottom of circumferential grooves showed that the level of irregularity of pressure increased as flow rate decreased. Based on the characteristic of increasing irregularity of the pressure signals inside the circumferential grooves as stall approaches, an autocorrelation technique was applied to the stall warning. This technique could be used to provide warning against stall and estimate real-time stall margins in compressors with casing treatments.

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Failure mechanism of casing treatment in improving stability of a highly loaded two-stage axial compressor

Aerospace Science and Technology ◽

10.1016/j.ast.2020.105979 ◽

2020 ◽

Vol 105 ◽

pp. 105979

Author(s):

Wei Wang ◽

Jin-ling Lu ◽

Xing-qi Luo ◽

Rui Huang ◽

Wu-li Chu

Keyword(s):

Failure Mechanism ◽

Axial Compressor ◽

Two Stage ◽

Casing Treatment ◽

Highly Loaded

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Effect of Novel Casing Treatment on the Suppression of Stall Precursor in a Transonic Compressor

Volume 2D: Turbomachinery ◽

10.1115/gt2014-26439 ◽

2014 ◽

Cited By ~ 2

Author(s):

Dakun Sun ◽

Xiaofeng Sun ◽

Xiaohua Liu ◽

Feng Lin ◽

Nie Chao Qun

Keyword(s):

Perforated Plate ◽

Area Ratio ◽

Open Area ◽

Stall Inception ◽

Stall Margin ◽

Casing Treatment ◽

Transonic Compressor ◽

Stall Margin Improvement ◽

Stall Precursor ◽

Casing Treatments

A kind of novel casing treatment is proposed to realize stall margin enhancement by suppressing stall precursor in turbomachinery. In view of its different configuration and mechanism, such casing treatment is named as stall precursor-suppressed casing treatment in the present work, or SPS casing treatment for short. In the present work, the experiments of SPS casing treatment are conducted in a transonic compressor J69 Rotor/Stage. The SPS casing treatment which consists of a backchamber and a perforated plate is designed according to a proposed theoretical model. It is noted that the open area ratio of the casing treatment is only 4–12%, which is much smaller than traditional casing treatments with over 50% open area ratio. The tests show that the SPS casing treatment can improve the stall margin by 8–12% for J69 Rotor, and 4–12% for J69 Stage. Meanwhile, the mechanism of stall margin improvement with such casing treatment will be revealed in this investigation. Comparing with the evolution of the precursors without casing treatments, the propagation of the stall inception waves will be suppressed and the non-linear development of the stall process will be delayed under the casing treatment case.

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Experimental and model investigations of SPS casing treatment on a two-stage compressor

Propulsion and Power Research ◽

10.1016/j.jppr.2021.02.001 ◽

2021 ◽

Vol 10 (1) ◽

pp. 1-14

Author(s):

Xu Dong ◽

Letian Zhang ◽

Dakun Sun ◽

Xiaofeng Sun

Keyword(s):

Two Stage ◽

Casing Treatment

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Effects of Rotating Inlet Distortion on Compressor Stability With Stall Precursor-Suppressed Casing Treatment

Journal of Fluids Engineering ◽

10.1115/1.4030492 ◽

2015 ◽

Vol 137 (11) ◽

Cited By ~ 9

Author(s):

Xu Dong ◽

Dakun Sun ◽

Fanyu Li ◽

Donghai Jin ◽

Xingmin Gui ◽

...

Keyword(s):

Stability Problem ◽

Axial Fan ◽

Stall Margin ◽

Casing Treatment ◽

Inlet Distortion ◽

Large Size ◽

Flow Disturbances ◽

Stall Margin Improvement ◽

The Stability ◽

Stall Precursor

This paper conducts an experimental research of rotating inlet distortion on a low-speed large size test compressor with emphasis on the stability problem of axial fan/compressors, and the stall margin enhancement with a kind of stall precursor-suppressed (SPS) casing treatment. Some results on compressor stall margin and prestall behavior under the restriction of rotating inlet distortion are presented. The experimental results show that whether the inlet distortion is co-rotating or counter-rotating, the SPS casing treatment can still improve the stall margin without leading to additional efficiency loss caused by such configuration. The experiment results also show that the mechanism of the stall margin improvement with such casing treatment is associated with delaying the nonlinear development of the stall precursor waves and weakening the unsteady flow disturbances in a compression system.

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Further Investigation on Transonic Compressor Stall Margin Enhancement With Stall Precursor-Suppressed Casing Treatment

Journal of Turbomachinery ◽

10.1115/1.4031775 ◽

2015 ◽

Vol 138 (2) ◽

Cited By ~ 8

Author(s):

Dakun Sun ◽

Chaoqun Nie ◽

Xiaohua Liu ◽

Feng Lin ◽

Xiaofeng Sun

Keyword(s):

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Rotational Speed ◽

Solid Wall ◽

Stall Inception ◽

Stall Margin ◽

Casing Treatment ◽

Transonic Compressor ◽

Stall Precursor

A kind of casing treatment, named as stall precursor-suppressed (SPS), has been developed recently, which was proved to be able to effectively improve stall margin (SM) without significant efficiency loss in low-speed axial flow compressors and a transonic compressor rotor. In this paper, the effectiveness of the SPS casing treatment is investigated in a single-stage transonic compressor. Based on an extended stall inception model, the quantitative evaluation of the SM enhancement by the SPS casing treatment is presented for the transonic compressor stage. The model predicts that a 2.5–6.8% of stall margin improvement (SMI), which is defined in terms of mass flow rate at stall inception, can be achieved at the design rotational speed. The experimental results show that the SPS casing treatment can achieve 3.5–9.3% of the SMI at 95% design rotational speed. Due to the fact that the distributions of the total pressure ratio along the spanwise direction are kept the same as those of the solid wall casing at the same mass flow rate, the SPS casing treatments with a small open area ratio and large backchamber enhance the SM without a recognizable efficiency loss and a migration of the pressure-rise characteristics. Furthermore, the mechanism of SMI with the SPS casing treatment is investigated in the experiments. In comparison with the solid wall casing, the emergence and the evolution of the stall inception waves are suppressed and the nonlinear development of the stall process is delayed with the SPS casing treatment.

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