### Abstract

Original language | English |
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Title of host publication | ASME Turbo Expo 2010 |

Subtitle of host publication | Power for Land, Sea, and Air, GT 2010 |

Place of Publication | New York, U. S. A. |

Publisher | American Society of Mechanical Engineers (ASME) |

Pages | 1235-1245 |

Number of pages | 11 |

Volume | 4 |

Publication status | Published - 2010 |

Event | ASME Turbo Expo 2010: Power for Land, Sea, and Air, GT 2010, June 14, 2010 - June 18, 2010 - Glasgow, UK United Kingdom Duration: 1 Jan 2010 → … |

### Publication series

Name | Proceedings of the ASME Turbo Expo |
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Publisher | American Society of Mechanical Engineers |

### Conference

Conference | ASME Turbo Expo 2010: Power for Land, Sea, and Air, GT 2010, June 14, 2010 - June 18, 2010 |
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Country | UK United Kingdom |

City | Glasgow |

Period | 1/01/10 → … |

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### Cite this

*ASME Turbo Expo 2010: Power for Land, Sea, and Air, GT 2010*(Vol. 4, pp. 1235-1245). (Proceedings of the ASME Turbo Expo). New York, U. S. A.: American Society of Mechanical Engineers (ASME).

**Prediction of ingress through turbine rim seals : Part 2 combined ingress.** / Owen, J. Michael; Pountney, Oliver; Lock, Gary.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

*ASME Turbo Expo 2010: Power for Land, Sea, and Air, GT 2010.*vol. 4, Proceedings of the ASME Turbo Expo, American Society of Mechanical Engineers (ASME), New York, U. S. A., pp. 1235-1245, ASME Turbo Expo 2010: Power for Land, Sea, and Air, GT 2010, June 14, 2010 - June 18, 2010, Glasgow, UK United Kingdom, 1/01/10.

}

TY - GEN

T1 - Prediction of ingress through turbine rim seals

T2 - Part 2 combined ingress

AU - Owen, J. Michael

AU - Pountney, Oliver

AU - Lock, Gary

PY - 2010

Y1 - 2010

N2 - In Part 1 of this two-part paper, the orifice equations were solved for the case of externally-induced ingress, where the effects of rotational speed are negligible. In Part 2, the equations are solved, analytically and numerically, for combined ingress (CI) where the effects of both rotational speed and external flow are significant. For the CI case, the orifice model requires the calculation of three empirical constants, including Cd,e,RI and Cd,e,EI, the discharge coefficients for rotationally-induced (RI) and externally-induced (EI) ingress. For the analytical solutions, the external distribution of pressure is approximated by a linear saw-tooth model; for the numerical solutions, a fit to the measured pressures is used. It is shown that, although the values of the empirical constants depend on the shape of the pressure distribution used in the model, the theoretical variation of C w,min (the minimum nondimensional sealing flow rate needed to prevent ingress) depends principally on the magnitude of the peak-to-trough pressure difference in the external annulus. The solutions of the orifice model for Cw,min are compared with published measurements, which were made over a wide range of rotational speeds and external flow rates. As predicted by the model, the experimental values of Cw,min could be collapsed onto a single curve, which connects the asymptotes for RI and EI ingress at the respective smaller and larger external flow rates. At the smaller flow rates, the experimental data exhibit a minimum value of Cw,min, which undershoots the RI asymptote. Using an empirical correlation for C d,e, the model is able to predict this undershoot, albeit smaller in magnitude than the one exhibited by the experimental data. The limit of the EI asymptote is quantified, and it is suggested how the orifice model could be used to extrapolate effectiveness data obtained from an experimental rig to engine-operating conditions.

AB - In Part 1 of this two-part paper, the orifice equations were solved for the case of externally-induced ingress, where the effects of rotational speed are negligible. In Part 2, the equations are solved, analytically and numerically, for combined ingress (CI) where the effects of both rotational speed and external flow are significant. For the CI case, the orifice model requires the calculation of three empirical constants, including Cd,e,RI and Cd,e,EI, the discharge coefficients for rotationally-induced (RI) and externally-induced (EI) ingress. For the analytical solutions, the external distribution of pressure is approximated by a linear saw-tooth model; for the numerical solutions, a fit to the measured pressures is used. It is shown that, although the values of the empirical constants depend on the shape of the pressure distribution used in the model, the theoretical variation of C w,min (the minimum nondimensional sealing flow rate needed to prevent ingress) depends principally on the magnitude of the peak-to-trough pressure difference in the external annulus. The solutions of the orifice model for Cw,min are compared with published measurements, which were made over a wide range of rotational speeds and external flow rates. As predicted by the model, the experimental values of Cw,min could be collapsed onto a single curve, which connects the asymptotes for RI and EI ingress at the respective smaller and larger external flow rates. At the smaller flow rates, the experimental data exhibit a minimum value of Cw,min, which undershoots the RI asymptote. Using an empirical correlation for C d,e, the model is able to predict this undershoot, albeit smaller in magnitude than the one exhibited by the experimental data. The limit of the EI asymptote is quantified, and it is suggested how the orifice model could be used to extrapolate effectiveness data obtained from an experimental rig to engine-operating conditions.

M3 - Conference contribution

VL - 4

T3 - Proceedings of the ASME Turbo Expo

SP - 1235

EP - 1245

BT - ASME Turbo Expo 2010

PB - American Society of Mechanical Engineers (ASME)

CY - New York, U. S. A.

ER -