Aerodynamic characterization of a transonic axial flow compressor stage – with asymmetric tip clearance effects

Kumar, S. Satish; Alone, Dilipkumar Bhanudasji; Thimmaiah, Shobhavathy M.; Mudipalli, Janaki Rami Reddy; Ganguli, Ranjan; Kandagal, SB; Jana, Soumendu

doi:10.1016/j.ast.2018.09.001

Cited by 20 publications

(5 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Most of the researches on nonuniform tip clearance concluded that it led to performance degradation 6,8,15 or had little effect on compressor performance. 9–11 Further analysis is carried out below to interpret the performance improvement of the non-axisymmetric case.…”

Section: Effect Of Non-axisymmetric Clearance On Overall Performancementioning

confidence: 99%

“…Young et al 8 quantified the effects of clearance and eccentricity on compressor performance and pointed that the eccentricity of the tip clearance then further exacerbated the negative effects of increasing tip clearance. However, Cameron et al 9,10 and Kumar et al 11 found that the introduction of small levels of steady and unsteady tip clearance asymmetry did not significantly alter the time-averaged performance of the stage. In an aero-engine where tip clearance size and eccentricity change during each flight cycle and over the life of the compressor, 12 the redistribution of flow massively influences stall inception during throttling, 13,14 and the stall will occur in nonuniform clearance configurations once the minimum mass flow reaches to the local stall mass flow.…”

Section: Introductionmentioning

confidence: 97%

See 1 more Smart Citation

Some effects of non-axisymmetric tip clearance layout on axial compressor aerodynamics

Zhang

Zhuang

Teng

et al. 2021

Proceedings of the Institution of Mechanical Engineers, Part A:

View full text Add to dashboard Cite

A steady and unsteady numerical research is carried out to explore some effects of a specific non-axisymmetric tip clearance layout on the overall performance and stability of an axial compressor stage. For a 4-stage low-speed research compressor (LSRC) in Shanghai Jiao Tong University (SJTU), one-eighth annulus of the inlet guide vane and the first stage rotor was modeled for this study. After the validation for the uniform tip clearance case, a specific non-axisymmetric tip clearance layout is chosen from several random cases generated by the Gaussian Probabilistic Density Function method. Unsteady time-averaged results at the near stall condition show that the chosen non-axisymmetric layout can improve the isentropic efficiency by 1.3% and extend the stall margin by 4%. Detailed analyses on flow fields are carried out to interpret the performance improvement. Due to the circumferential layout of clearance sizes, the inlet mass flow and incidence are redistributed in both the radial and circumferential directions. It leads to blade loading and tip leakage flow varying with the tip clearance size. The quantification of blockage manifests that the blockage arising from the tip leakage flow is significantly alleviated in the non-axisymmetric layout, which leads to improvements in overall performance and stall margin. Transient flow fields at the rotor tip are also analyzed at the near stall condition. For the non-axisymmetric layout, low-momentum regions originating from larger clearance sizes oscillate and develop downstream in one blade passage period.

show abstract

Section: Effect Of Non-axisymmetric Clearance On Overall Performancementioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

Some effects of non-axisymmetric tip clearance layout on axial compressor aerodynamics

Zhang

Zhuang

Teng

et al. 2021

Proceedings of the Institution of Mechanical Engineers, Part A:

View full text Add to dashboard Cite

show abstract

“…In addition, the circumferential nonuniformity of tip clearance has also been investigated. 25 According to the research of Chen et al, 26 the overall performance and flow structures are affected by two factors: clearance nonuniformity and average clearance level. There is a clear decreasing trend of the fan performance and stall margin with the increase of these two factors.…”

Section: Introductionmentioning

confidence: 99%

Attenuation of leakage flow using axially nonuniform tip clearance in high loading transonic compressor rotor

Cui

Liu

Wang

et al. 2021

Proceedings of the Institution of Mechanical Engineers, Part G:

View full text Add to dashboard Cite

Several linearly nonuniform clearances have been designed to explore a novel strategy for attenuation of leakage flow in tip region of high loading transonic rotor and the effects of axially nonuniform clearance on detailed tip flow structure and stable operating range of rotor have been discussed as well. The results showed that the tip flow characteristic of rotor is affected mainly by the combined effects of two parts of low-velocity flow, which are produced by interaction of leakage flow with passage shock and boundary layer separation near suction side, respectively. However, the stall margin of rotor and isentropic efficiency near tip region is dominated significantly by the former part, and the local changes of size and shape of tip clearance have a large influence on it. Once the strength of leakage flow decreases due to clearance size variation, the boundary layer separation near suction side of blade tip worsens gradually and increases additional aerodynamic losses in passage. Both the mass flow rate and mixing losses of the tip leakage flow can be reduced due to a smaller size of clearance existing in front part of clearance of rotor with a linearly divergent clearance shape, and the area of low-velocity region near pressure side has reduced accordingly. By contrast, a linearly convergent shape of tip clearance can increase both the area of low-velocity region and the mixing loss of leakage flow as a result of a larger size of clearance existing over the front part of blade tip of rotor. Eventually, a divergent shape of tip clearance with a reasonable minimum size near leading edge of blade tip is preferred for transonic rotor in consideration of the benefit in stall margin improvement with nearly no penalty in efficiency.

show abstract

“…Furthermore, the stability margin of the concentric cases was reduced by roughly 9.5% per 1% increase in the tip clearance. Kumar et al 23 experimentally and numerically investigated the performance of a transonic axial compressor with non-uniform tip clearance. Results were in line with Graf et al 20 Analytical compressor models were developed by Gordon 18 to study the effects of rotating tip clearance asymmetry in axial compressors.…”

Section: Introductionmentioning

confidence: 99%

Rotating tip clearance asymmetry and role of endwall injection in stability desensitization of a transonic fan

Khaleghi

2021

Proceedings of the Institution of Mechanical Engineers, Part A:

View full text Add to dashboard Cite

The current study is aimed at understanding the effect of rotating tip clearance asymmetry on the operability and performance of a transonic compressor. Another objective of this investigation is to determine the influence of tip injection on reducing the detrimental effects of clearance asymmetry. Three dimensional unsteady Reynolds-averaged Navier–stokes simulations have been performed from choke to stall for different arrangements of non-uniform blade heights in a transonic fan. Furthermore, numerical computations have been conducted with endwall injection of air. The numerical results have been validated against experimental data. Results show that having the same mean tip clearance, the asymmetric compressor is less stable than the axisymmetric configuration. However, the peak pressure rise is found to be almost linearly correlated to the mean tip clearance for both the axisymmetric and asymmetric compressors. It is found that tip injection can desensitize the compressor to the tip clearance asymmetry. Results further reveal that tip clearance asymmetry does not change the compressor path to instability. However, endwall injection is found to be able to change the compressor stalling mode. Investigations concerning rotating non-uniformity (caused by non-uniform blade heights) are very few in open literature. The obtained results can assist in predicting the effect of rotating tip clearance asymmetry on the stability and performance of high-speed compressor rotors. Furthermore, the results uncover how tip injection can desensitize the compressor stability and affect its path into instability, which is one of the most important questions in the turbomachinery world.

show abstract

Aerodynamic characterization of a transonic axial flow compressor stage – with asymmetric tip clearance effects

Cited by 20 publications

References 20 publications

Some effects of non-axisymmetric tip clearance layout on axial compressor aerodynamics

Some effects of non-axisymmetric tip clearance layout on axial compressor aerodynamics

Attenuation of leakage flow using axially nonuniform tip clearance in high loading transonic compressor rotor

Rotating tip clearance asymmetry and role of endwall injection in stability desensitization of a transonic fan

Contact Info

Product

Resources

About