F211 STUDY ON VIBRATION RESPONSE OF STEAM TURBINE VANE WITH HALF RING STRUCTURE(Steam Turbine-4)

2009 ◽  
Vol 2009.2 (0) ◽  
pp. _2-499_-_2-504_
Author(s):  
Yasutomo KANEKO ◽  
Kazushi MORI
Keyword(s):  
Steam Turbine ◽  
Ring Structure ◽  
Vibration Response ◽  
Turbine Vane

Effect of Material Damping of Steam Turbine Vane on Flutter Suppression

2012 ◽  
Author(s):  
Yasutomo Kaneko ◽  
Kazushi Mori ◽  
Hiroharu Ohyama
Keyword(s):  
Steam Turbine ◽  
Aerodynamic Force ◽  
Working Fluid ◽  
Material Damping ◽  
Element Analysis ◽  
Flutter Suppression ◽  
Aerodynamic Damping ◽  
Turbine Vane ◽  
3D Fea ◽  
The Stability

The vane used in a low pressure end of steam turbine is usually fixed to shroud and casing by welding both ends. In such a vane structure, the damping in loading operation is comprised of the material damping and the aerodynamic damping, because the structural damping is very small. In this paper, first, the vane is modeled by the uniform beam fixed at both ends, and the effect of the material damping on the vane flutter is studied. In the stability analysis, the simple one-degree-of-freedom model is applied, where the linear aerodynamic model is used. In other words, it is assumed that the aerodynamic force due to the working fluid is proportional to the vane velocity and the negative damping coefficient does not change with amplitude. The allowable aerodynamic damping for the vane flutter is calculated and compared for the solid vane and the hollow vane. In addition, the vibration analysis of the actual steam turbine vane is carried out by 3D FEA (Finite Element Analysis), and the material damping of the solid and hollow vane is calculated by use of the results by FEA. The stability of the solid vane and the hollow vane on the flutter is also evaluated by use of the results calculated by FEA. From these results, the material damping characteristics of the steam turbine vane are clarified, as well as the effect of the material damping of the steam turbine vane on the flutter suppression.

Analysis and Verification Test of Damping Characteristics of Steam Turbine Hollow Vane With Friction Damper

2014 ◽  
Author(s):  
Yasutomo Kaneko ◽  
Hiroyuki Yamashita ◽  
Hiroharu Ooyama
Keyword(s):  
Steam Turbine ◽  
High Capacity ◽  
Analysis Method ◽  
Structural Damping ◽  
Friction Damper ◽  
Flat Plates ◽  
Aerodynamic Damping ◽  
Damping Characteristics ◽  
Excited Vibration ◽  
Turbine Vane

A vane used in a low pressure end of a steam turbine is usually fixed to a shroud and a casing by welding both ends. In such a vane structure, the damping in loading operation is comprised of the material damping and the aerodynamic damping, because the structural damping is very small. In the blade and vane of high-capacity steam turbine units, the aerodynamic damping may become negative under the high loading operation, and some papers reported the self-excited vibration of the blade and vane caused by the negative aerodynamic damping. Recently, in order to increase the reliability of the steam turbine vane, a hollow vane with a friction damper has been proposed. In such a steam turbine vane, the curved damper piece made of the thin plate is inserted into the hollow vane, and the structural damping is added by use of the friction between the damper piece and the vane. In this paper, for the purpose of clarifying the damping characteristics of the hollow vane with the friction damper, first, the excitation test of the model vane is carried out. In the excitation test of the model vane, the damping characteristics of the model vane consisting of two flat plates and the thin curved damper piece are measured, changing the excitation force. Second, the analysis method for predicting the damping characteristics of the hollow vane with the friction damper, which utilizes the conventional modal analysis method and the harmonic balance method, is proposed. The validity of the analysis method is verified by comparing the measured damping with the calculated ones. After verifying the analysis method, the actual steam turbine hollow vane with the friction damper is also analyzed, and the effect of the damper stiffness on the damping characteristics is examined. Finally, the actual hollow vane with the friction damper for the high-capacity steam turbine unit is designed and manufactured, and the excitation test of the actual hollow vane is carried out. From these results, the damping characteristics of the hollow vane with the friction damper are clarified.

scholarly journals Application of numerical modelling for determining the optimal position of the suction slot in the steam turbine vane cascade

2020 ◽  
Vol 1683 ◽  
pp. 022067
Author(s):  
V G Gribin ◽  
A A Tishchenko ◽  
R A Alekseev ◽  
I Yu Gavrilov ◽  
V V Popov ◽  
...  
Keyword(s):  
Numerical Modelling ◽  
Steam Turbine ◽  
Optimal Position ◽  
Turbine Vane ◽  
Suction Slot

scholarly journals Inlet Flux Influence to Aerodynamic Performance of Steam Turbine Vane Cascade

2014 ◽  
Vol 6 (12) ◽  
pp. 1282-1286
Author(s):  
Feng Zi-Ming ◽  
Ding Huanhuan ◽  
Li Chunhong ◽  
Xu Ping
Keyword(s):  
Steam Turbine ◽  
Aerodynamic Performance ◽  
Turbine Vane

Vortexing Methods to Reduce Secondary Losses in a Low Reaction Industrial Turbine

2015 ◽  
Author(s):  
Srikanth Deshpande ◽  
Marcus Thern ◽  
Magnus Genrup
Keyword(s):  
Steady State ◽  
Steam Turbine ◽  
Pressure Loss ◽  
Total Pressure ◽  
Stokes Equations ◽  
Navier Stokes ◽  
Blade Design ◽  
Navier Stokes Equations ◽  
Commercial Code ◽  
Turbine Vane

Vortexing methods implemented on an industrial steam turbine vane in order to reduce secondary losses are discussed. Three vortexing methods presented are prismatic blade design, inverse vortex and parabolic forced vortex. Baseline industrial vane considered for study is a prismatic blade design. Modifications are analysed numerically using commercial code CFX. Modified vanes along with baseline rotor as a complete stage is considered for analysis. Steady state Reynolds averaged Navier Stokes equations are solved. Total pressure loss (TPL) is used as target functions to monitor reduction in secondary losses. Rotor considered for the study is the baseline industrial rotor for all design modifications of vane.

Small Angle Electron Scattering From Vacuum Condensed Metallic Films

1968 ◽  
Vol 26 ◽  
pp. 380-381
Author(s):  
J. Silcox ◽  
R. H. Wade
Keyword(s):  
Electron Scattering ◽  
Small Angle ◽  
Ring Structure ◽  
Two Dimensional ◽  
Metallic Films ◽  
Micro Structure ◽  
Angle Scattering ◽  
The Fourier Transform ◽  
Source Of Information ◽  
Kinematical Theory

Recent work has drawn attention to the possibilities that small angle electron scattering offers as a source of information about the micro-structure of vacuum condensed films. In particular, this serves as a good detector of discontinuities within the films. A review of a kinematical theory describing the small angle scattering from a thin film composed of discrete particles packed close together will be presented. Such a model could be represented by a set of cylinders packed side by side in a two dimensional fluid-like array, the axis of the cylinders being normal to the film and the length of the cylinders becoming the thickness of the film. The Fourier transform of such an array can be regarded as a ring structure around the central beam in the plane of the film with the usual thickness transform in a direction normal to the film. The intensity profile across the ring structure is related to the radial distribution function of the spacing between cylinders.

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