Identificaci

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ASME paper GT2004-54160
July 22, 2004
Identificación de parámetros en soportes de
maquinaria rotativa
Luis San Andrés Turbomachinery
Laboratory Texas AM University
Oscar De Santiago Dresser-Rand Co.
IX Ecuadorian Congress on Mathematics Quito,
Ecuador
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Justification Increasingly stringent vibration
limits imposed by industry standards (API 617,
7th Edition, for example) require prediction and
validation of Critical Speeds and Amplification
Factors during shop testing of commissioned turbo
machinery.
Parameter identification in the field is also
promising for condition monitoring and
troubleshooting, and in the near future for
self-adapting rotor-bearing control systems.

• OBJECTIVES
• Based on previously developed methods, this
  work intends to
• Extend the identification method to flexible
  rotor-bearing systems
• Validate these methods for in-situ estimation of
  bearing force coefficients

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Reorder EOMs as
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Note still needed two imbalance runs
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196 Hz
384 Hz
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Measurements for increasing imbalances
Linearity of rotor response? Divide amplitude
for two largest imbalances by amplitude of lowest
imbalance (should overlap the curves)
CX at rotor mid span
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Stiffness Coefficients
Left Direct Right Cross-coupled
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Damping Coefficients
Left Direct Right Cross-coupled
XX, XY YY, YX
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Force Coefficients Comparison to earlier results
Lines original identification method Symbols
current - enhanced procedure
Left Direct Right Cross-coupled
10.5 gram
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Conclusions
Robust method to identify bearing support force
coefficients in flexible rotor-bearing
systems Enhanced for practical use sensors not
at mid plane of bearings. Procedure sensitive
to numerical conditioning of test data. In
particular at critical speeds in systems with
little damping. Imbalance must be large enough
to reduce NSR Procedure NOT very sensitive to
noise (up to 10)