Numerical study of aero-excitation of steam-turbine rotor blade self-oscillations

Abstract The impact of the unsteadiness in the considered turbulence quantities on the numerical prediction of the aeroelastic behavior of a low-pressure turbine (LPT) rotor blade is evaluated by means of a numerical study. In this context, one of the main objectives of this work is to compare different nonlinear harmonic balance (HB) approaches—one neglecting and one considering the unsteadiness in the employed turbulence models—with a conventional nonlinear solver of the unsteady Reynolds-averaged Navier–Stokes (URANS) equations in the time domain. In order to avoid unphysical oscillations in the turbulence quantities caused by the Gibbs phenomenon in the chosen HB approach, a filter method based on the Lanczos filter is developed. The developed filter method is applied in the course of the HB simulations considering the unsteadiness in the underlying turbulence model. Furthermore, the impact of its application on the solution of the flow field and on the unsteady surface pressure of the rotor blade, in particular, is discussed in the context of this work.

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Numerical and Experimental Vibration Analysis of a Steam Turbine Rotor Blade

Tehnički glasnik ◽

10.31803/tg-20210302210045 ◽

2021 ◽

Vol 15 (4) ◽

pp. 462-466

Author(s):

Marko Katinić ◽

Marko Ljubičić

Keyword(s):

Numerical Model ◽

Modal Analysis ◽

Steam Turbine ◽

Vibration Analysis ◽

Rotor Blade ◽

High Reliability ◽

Turbine Rotor ◽

Rotor Blades ◽

Turbine Rotor Blade ◽

Computer Environment

Damage to the rotor blade of a steam turbine is a relatively common problem and is one of the leading causes of sudden and unplanned shutdowns of a steam turbine. Therefore, the high reliability of the rotor blades is very important for the safe and economical operation of the steam turbine. To ensure high reliability, it is necessary to perform a vibration analysis of the rotor blades experimentally and in a computer environment. In this paper, a modal analysis was performed on the twisted blade of the last stage of the turbine in the Ansys software. The results of the modal analysis of the stationary rotor blade were compared with the results obtained by the bump test, which confirmed the numerical model of the blade. A modal analysis of a rotating rotor blade was performed on the same numerical model, and Campbell diagrams were plotted to determine the critical speed

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Steam Turbine Rotor Blade Cascades Aerodynamic Performance Research at Off-Design Incidence

ASME 2012 Gas Turbine India Conference ◽

10.1115/gtindia2012-9510 ◽

2012 ◽

Author(s):

Zi-Ming Feng ◽

Jin-Dong Zhang ◽

Hui-Bin Gu

Keyword(s):

Steam Turbine ◽

Performance Test ◽

Static Pressure ◽

Pressure Coefficient ◽

Turbine Rotor ◽

Aerodynamic Performance ◽

Blade Profile ◽

Turbine Rotor Blade ◽

Steam Turbine Rotor ◽

Profile Loss

A steam turbine rotor cascades aerodynamic performance test are performed in annular cascade wind tunnel. The tested blade is curved and has rear-loaded profile characteristic. The main goal of this research project is to measure the off-design incidence aerodynamic performance, such as static pressure coefficient, total pressure loss and streamline. The test result indicates that incidence variation has little influence to the static pressure coefficient along blade profile, but has relatively significant influence to the profile loss. The blade profile loss increase continuously with the incidence sequence at 0°, −10° and +10°. At the tested incidence, the secondary flow intensity was very weak and its influence area was very small too. It states the aft-loaded blade profile has good incidence suitability.

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A linear cascade tunnel for flow investigations of steam turbine rotor tip blades in subsonic nucleating flows

SN Applied Sciences ◽

10.1007/s42452-021-04291-3 ◽

2021 ◽

Vol 3 (2) ◽

Author(s):

Vital Kumar Yadav Pillala ◽

B. V. S. S. S. Prasad ◽

N. Sitaram ◽

M. Mahendran ◽

Debasish Biswas ◽

...

Keyword(s):

Steam Turbine ◽

Turbine Rotor ◽

Turbine Cascade ◽

Flow Measurements ◽

Linear Cascade ◽

Dry Air ◽

Steam Turbine Rotor ◽

Pressure Distributions ◽

Working Medium ◽

Exit Mach Number

AbstractThe paper presents details of a unique experimental facility along with necessary accessories and instrumentation for testing steam turbine cascade blades in wet and nucleating steam. A steam turbine rotor tip cascade is chosen for flow investigations. Cascade inlet flow measurements show uniform conditions with dry air and steam and dry air mixture of different ratios. Exit flow surveys indicate that excellent flow periodicity is obtained. Blade surface static pressure and exit total pressure distributions are also presented with dry air and with steam and dry air mixture of different ratios as the working medium at an exit Mach number of 0.52.

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