JZUS - Journal of Zhejiang University SCIENCE

Journal of Zhejiang University SCIENCE A

Accepted manuscript available online (unedited version)

Investigation of flow characteristics in a rotor-stator cavity under crossflow using wall-modelled large-eddy simulation

Author(s): Lei XIE, Qiang DU, Guang LIU, Zengyan LIAN, Yaguang XIE, Yifu LUO
Affiliation(s): Key Lab of Light-duty Gas-turbine, Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190, China; more
Corresponding email(s): duqiang@iet.cn
Key Words: Wall-modeled large-eddy simulation (WMLES); Rotor-stator cavity; Flow instability; Reynolds-averaged Navier-Stokes (RANS)

Share this article to： More \|Next Paper >>>

Abstract: Rotor-stator cavities are frequently encountered in engineering applications such as gas turbine engines. They are usually subject to an external hot mainstream crossflow which in general is highly swirled under the effect of the nozzle guide vanes. To avoid hot mainstream gas ingress, the cavity is usually purged by a stream of sealing flow. The interactions between the external crossflow, cavity flow, and sealing flow are complicated and involve all scales of turbulent unsteadiness and flow instability which are beyond the resolution of the Reynolds-average approach. To cope with such a complex issue, a wall-modeled large-eddy simulation (WMLES) approach is adopted in this study. In the simulation, a 20° sector model is used and subjected to a uniform pre-swirled external crossflow and a stream of radial sealing flow. It is triggered by a convergent Reynolds-averaged Navier-Stokes (RANS) result in which the shear stress transport (SST) turbulent model is used. In the WMLES simulation, the Smagoringsky sub-grid scale (SGS) model is applied. A scalar transportation equation is solved to simulate the blending and transportation process in the cavity. The overall flow field characteristics and deviation between RANS and WMLES results are discussed first. Both RANS and WMLES results show a Batchelor flow mode, while distinct deviation is also observed. Deviations in the small-radius region are caused by the insufficiency of the RANS approach in capturing the small-scale vortex structures in the boundary layer while deviations in the large-radius region are caused by the insufficiency of the RANS approach in predicting the external crossflow ingestion. The boundary layer vortex and external ingestion are then discussed in detail, highlighting the related flow instabilities. Finally, the large-flow structures induced by external flow ingress are analyzed using unsteady pressure oscillation signals.

基于壁面函数大涡模拟研究横流通道对转静系盘腔流动特性的影响

作者：谢垒^1,2,3，杜强^1,2,3，柳光^1,2,3，廉曾妍^1,2,3，谢亚广^1,2,3，罗一夫^1,2,3
机构：¹中国科学院工程热物理研究所，轻型动力实验室，中国北京，100190；²中国科学院大学，工程科学学院，中国北京，100049；³中国科学院轻型动力创新研究院，中国北京，100190
目的：本文旨在探究带有均匀预旋速度的外部横流对转静系盘腔流动特性的影响，从而指导对真实发动机条件下涡轮盘腔流动特性的研究。
创新点：1.采用壁面函数大涡模拟（WMLES）方法，获得了带有横流通道的转静系盘腔更为精细的流场结构；2.识别了盘腔轮缘处的开尔文-赫姆霍茨（K-H）不稳定性，并探究了K-H剪切涡结构对轮缘处流动特性的影响。
方法：1.通过高精度大涡模拟方法，捕捉流场中的精细化流场结构。2.结合理论推导，通过对于流动结构的机理和动力学分析，探究外部横流和盘腔耦合流动特性。
结论：1.由于雷诺平均（RANS）模拟对壁面小尺度涡结构和输运方程的解析能力不足，所以RANS模拟流场与WMLES模拟流场出现了明显偏差。2.在横流和盘腔流动的耦合作用下，由于轮缘处的速度剪切诱导产生K-H涡结构，所以这些涡结构将会加强轮缘处的外部入侵和盘腔出流流动。3.在外部入侵和盘腔出流的影响下，盘腔端区发现了大尺度流动结构；这些大尺度流动结构以一定的转速旋转，且其转速和数量可以通过快速傅里叶变换以及相关性分析确定。

关键词组：壁面函数大涡模拟；转-静系盘腔；流动不稳定性；RANS

Reference

[1]BayleyFJ, OwenJ, 1970. The fluid dynamics of a shrouded disk system with a radial outflow of coolant. Journal of Engineering for Gas Turbines and Power, 92(3):335-341.

[2]BhavnaniSH, KhilnaniVI, TsaiLC, et al., 1992. Effective sealing of a disk cavity using a double-toothed rim seal. Proceedings of the ASME International Gas Turbine and Aeroengine Congress and Exposition, No. V001T01A127.

[3]Childs PRN, 2011. Chapter 7: rotating cavities. In: Childs PRN (Ed.), Rotating Flow. Butterworth-Heinemann, Oxford, UK, p.249-298.

[4]GaoF, ChewJW, 2021. Evaluation and application of advanced CFD models for rotating disc flows. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 235(23):‍6847-6864.

[5]GaoF, ChewJW, MarxenO, 2020. Inertial waves in turbine rim seal flows. Physical Review Fluids, 5(2):024802.

[6]GeorgiadisNJ, RizzettaDP, FurebyC, 2010. Large-eddy simulation: current capabilities, recommended practices, and future research. AIAA Journal, 48(8):1772-1784.

[7]HorwoodJTM, HualcaFP, ScobieJA, et al., 2019. Experimental and computational investigation of flow instabilities in turbine rim seals. Journal of Engineering for Gas Turbines and Power, 141(1):011028.

[8]Hualca-TigsilemaFP, 2020. An Experimental Study of Ingress Through Gas-Turbine Rim Seals. PhD Thesis, University of Bath, Bath, UK.

[9]JakobyR, ZiererT, LindbladK, et al., 2004. Numerical simulation of the unsteady flow field in an axial gas turbine rim seal configuration. ASME Turbo Expo 2004: Power for Land, Sea, and Air, p.431-440.

[10]LarssonJ, KawaiS, BodartJ, et al., 2016. Large eddy simulation with modeled wall-stress: recent progress and future directions. Mechanical Engineering Reviews, 3(1):‍15-00418.

[11]LingwoodRJ, 1995. Absolute instability of the boundary layer on a rotating disk. Journal of Fluid Mechanics, 299:17-33.

[12]NakhchiME, NaungSW, RahmatiM, 2022. Influence of blade vibrations on aerodynamic performance of axial compressor in gas turbine: direct numerical simulation. Energy, 242:122988.

[13]NaungSW, NakhchiME, RahmatiM, 2021. Prediction of flutter effects on transient flow structure and aeroelasticity of low-pressure turbine cascade using direct numerical simulations. Aerospace Science and Technology, 119:107151.

[14]OMahoneyTSD, HillsNJ, ChewJW, et al., 2011. Large-eddy simulation of rim seal ingestion. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 225(12):2881-2891.

[15]OwenJM, 2011a. Prediction of ingestion through turbine rim seals—part I: rotationally induced ingress. Journal of Turbomachinery, 133(3):031005.

[16]OwenJM, 2011b. Prediction of ingestion through turbine rim seals—part II: externally induced and combined ingress. Journal of Turbomachinery, 133(3):031006.

[17]OwenJM, ZhouKY, PountneyO, et al., 2012a. Prediction of ingress through turbine rim seals—part I: externally induced ingress. Journal of Turbomachinery, 134(3):031012.

[18]OwenJM, PountneyO, LockG, 2012b. Prediction of ingress through turbine rim seals—part II: combined ingress. Journal of Turbomachinery, 134(3):031013.

[19]PalermoDM, GaoF, AmiranteD, et al., 2020. Wall-modelled large eddy simulations of axial turbine rim sealing. ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition, No. V07CT14A015.

[20]PhadkeUP, OwenJM, 1988a. Aerodynamic aspects of the sealing of gas-turbine rotor-stator systems: part 1: the behavior of simple shrouded rotating-disk systems in a quiescent environment. International Journal of Heat and Fluid Flow, 9(2):98-105.

[21]PhadkeUP, OwenJM, 1988b. Aerodynamic aspects of the sealing of gas-turbine rotor-stator systems: part 2: the performance of simple seals in a quasi-axisymmetric external flow. International Journal of Heat and Fluid Flow, 9(2):106-112.

[22]PhadkeUP, OwenJM, 1988c. Aerodynamic aspects of the sealing of gas-turbine rotor-stator systems: part 3: the effect of nonaxisymmetric external flow on seal performance. International Journal of Heat and Fluid Flow, 9(2):113-117.

[23]PogorelovA, SchneidersL, MeinkeM, et al., 2018. An adaptive Cartesian mesh based method to simulate turbulent flows of multiple rotating surfaces. Flow, Turbulence and Combustion, 100(1):19-38.

[24]RabsM, BenraFK, DohmenHJ, et al., 2009. Investigation of flow instabilities near the rim cavity of a 1.5 stage gas turbine. ASME Turbo Expo 2009: Power for Land, Sea, and Air, p.1263-1272.

[25]RoyceR, 2015. The Jet Engine. 5th Edition. John Wiley & Sons Inc., Chichester, UK.

[26]SanganCM, 2011. Measurement of Ingress Through Gas Turbine Rim Seals. PhD Thesis, University of Bath, Bath, UK.

[27]SanganCM, PountneyOJ, ZhouKY, et al., 2013. Experimental measurements of ingestion through turbine rim seals—part I: externally induced ingress. Journal of Turbomachinery, 135(2):021012.

[28]SaricWS, 1994. Görtler vortices. Annual Review of Fluid Mechanics, 26:379-409.

[29]SavovSS, AtkinsNR, 2017. A rim seal ingress model based on turbulent transport. ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition.

[30]SavovSS, AtkinsNR, UchidaS, 2017. A comparison of single and double lip rim seal geometries. Journal of Engineering for Gas Turbines and Power, 139(11):112601.

[31]ScobieJA, 2014. An Experimental Study of Gas Turbine Rim Seals. PhD Thesis, University of Bath, Bath, UK.

[32]SéveracÉ, PoncetS, SerreÉ, et al., 2007. Large eddy simulation and measurements of turbulent enclosed rotor-stator flows. Physics of Fluids, 19(8):085113.

[33]XieL, DuQ, LiuG, et al., 2021. Flow characteristics in turbine wheel space cavity. Energy Reports, 7:2262-2275.

Open peer comments: Debate/Discuss/Question/Opinion

<1>

- Go to

基于壁面函数大涡模拟研究横流通道对转静系盘腔流动特性的影响

Darkslateblue:Affiliate; Royal Blue:Author; Turquoise:Article

Reference