Journal of Computational & Applied Research in Mechanical Engineering (JCARME)

Articles in Press

Document Type : Research Paper

Authors

¹ Department of Mechanical Engineering, Iranian Research Organization for Science and Technology, Tehran, 3313193685, Iran

² School of Engineering, Macquarie University, Sydney, 2109, Australia

³ Mechanical Engineering Department, Iran University of Science and Technology, Tehran, 1684613114, Iran

https://doi.org/10.22061/jcarme.2025.11373.2495

Abstract

Hot gas ingestion, due to pressure differences in the turbine’s main flow path, is a challenge for gas turbine designers. It reduces aerodynamic performance, increases temperature gradients and thermal stresses, and decreases disk life. Designers should predict the ingestion and use the precise design of the cooling system, balancing the cooling and sealing flow, to enable the turbine to operate at higher temperatures (TIT) and efficiency to save costs and reduce harmful effects on turbine components. This paper presents a numerical investigation of a 1.5-stage test rig to study the ingestion phenomenon. A numerical tool was developed to enhance the coefficients and constants of a rapid ingestion model in a zero-dimensional secondary air system (SAS) code applicable to power plant turbines, such as Frame 9. Comparisons of CFD and test results demonstrate satisfactory agreement. Combining CFD and experimental validation, a numerical effectiveness map for the selected test rig rim seal is presented. CFD results post-processing reveals that increased cooling flow rate increases the pressure within the wheelspace, reduces swirl in the core region, and improves seal effectiveness. The swirl ratio was highly sensitive to SAS flow, increasing by 90% with a 50% reduction in SAS flow at a dimensionless radius of 0.85. Analysis of flow vectors exiting the axial clearance rim seal indicates that increasing the SAS flow rate enhances the main gas path flow disturbances. Moreover, at a constant flow rate, an increase in the first wheelspace flow rate increases the effectiveness of the second wheelspace by approximately 33%.

Graphical Abstract

Keywords

Main Subjects

Computational Fluid Dynamics (CFD)

References

[1] M. Owen and R. H. Rogers, Flow and Heat Transfer in Rotating Disc Systems, Vol. 1: Rotor-stator systems, Research Studies Press Ltd, England, (1989).

[2] Stewartson, “On the flow between two rotating coaxial disks”, Math. Proc. Cambridge Philos. Soc., Vol. 49, No. 2, pp. 333-341, (1953).

[3] J. M. Owen, K. Zhou, O. Pountney, M. Wilson and G. Lock, “Prediction of Ingress Through Turbine Rim Seals-Part I: Externally Induced Ingress”, J. Turbomach., Vol. 134, No. 3, pp. 1-13, (2012).

[4] M. Owen, “Prediction of ingestion through turbine rim seals-part I: Rotationally induced ingress”, J. Turbomach., Vol. 133, No. 3, pp. 1-9, (2011).

[5] J. W. Chew, F. Gao and D. M. Palermo, “Flow mechanisms in axial turbine rim sealing”, Proc. Inst. Mech. Eng., Part C: J. Mech. Eng. Sci., Vol. 233, pp. 7637–7657, (2018).

[6] D. E. Bohn, A. Decker, M. Hongwei and M. Wolff, “Influence of sealing air mass flow on the velocity distribution in and inside the rim seal of the upstream cavity of a 1.5 stage turbine”, Proc. of ASME Turbo Expo, Atlanta, Georgia, USA, (2003).

[7] P. Roy, J. Feng, D. Narzary and R. E. Paolillo, “Experiment on gas ingestion through axial-flow turbine rim seals”, J. Eng. Gas Turbines Power, Vol. 127, No. 3, pp. 573-582, (2005).

[8] O. Gentilhomme, N. J. Hills, A. B. Turner and J. W. Chew, “Measurement and analysis of ingestion through a turbine rim seal”, J. Turbomach., Vol. 125, No. 3, pp. 505-512, (2003).

[9] P. Palafox, Z. Ding, J. Bailey, T. Vanduser, K. Kirtley, K. Moore and R. Chupp, “A new 1.5 stage turbine wheelspace hot gas ingestion rig - Part I: Experimental test vehicle, measurement capability and baseline results”, Proc. of ASME Turbo Expo, San Antonio, Texas, USA, (2013).

[10] Barringer, A. Coward, K. Clark, K. A. Thole, J. Schmitz, J. Wagner, M. A. Alvin, P. Burke and R. Dennis, “The design of a steady aero thermal research turbine for studying secondary flow leakages and airfoil heat transfer”, ASME Turbo Expo, Düsseldorf, Germany, (2014).

[11] J. Scobie, “An Experimental Study of Gas Turbine Rim Seals”, PhD thesis, University of Bath, Dept. Mechanical Eng., London, (2014).

[12] C. M. Sangan, “Measurement of Ingress Through Gas Turbine Rim Seals”, PhD thesis, University of Bath, Dept. Mechanical Eng., London, (2011).

[13] A.Mirzamoghadam, G. Heitland, M. Morris, J. Smoke, M. Malak and J. Howe, “3D CFD ingestion evaluation of a high pressure turbine rim seal disk cavity”, ASME Turbo Expo, Berlin, Germany, (2008).

[14] Liu, A. Weaver, T. Shih, C. Sangan and G. Lock, “Modelling and Simulation of Ingress into the Rim Seal and Wheelspace of a Gas-Turbine Rotor-Stator Configuration”, in 53^rd AIAA Aerospace Sciences Meeting, Kissimmee, Florida, (2015).

[15] D. Soghe, C. Bianchini, C. M. Sangan, J. A. Scobie and G. D. Lock, “Numerical characterization of hot gas ingestion through turbine”, Proc. of ASME Turbo Expo, Seoul, South Korea, (2016).

[16] Lalwani, C. M. Sangan, M. Wilson and G. D. Lock, “Steady computations of ingress through gas turbine rim seals”, Proc. Inst. Mech. Eng., Part A: J. Power Energy, Vol. 229, No. 1, pp. 2-15, (2015).

[17] F. P. Hualca-Tigsilema, “An Experimental Study of Ingress Through Gas-Turbine Rim Seals”, PhD thesis, Dept. Mechanical Eng., University of Bath, London, (2020).

[18] “ANSYS CFX-Solver Theory Guide”, Inc., ANSYS, (2014).

[19] M. Patinios, J. A. Scobie, C. M. Sangan, J. M. Owen and G. D. Lock, “Measurements and Modeling of Ingress in a New 1.5 Stage Turbine Research Facility”, J. Eng. Gas Turbines Power, Vol. 139, pp. 012603, (2017).

[20] J. A. Scobie, C. M. Sangan, F. P. Hualca and G. D. Lock, “Egress interaction through turbine rim seals”, Proc. of ASME Turbo Expo, Charlotte, NC, USA, (2017).

Name *

Email Address *

Affiliation *

Comments *

Security Code *

CAPTCHA Image

Journal of Computational & Applied Research in Mechanical Engineering (JCARME)

Articles in Press, Accepted Manuscript
Available Online from 18 May 2025

Files

Share

How to cite

Statistics

Article View: 3,679
PDF Download: 629