Automated Optimisation of T-Root Rotor Grooves With B-Splines and Finite Element Analysis

2015 ◽  
Author(s):  
Jonathan Henson ◽  
Richard Dolan ◽  
Gareth Thomas ◽  
Christos Georgakis
Keyword(s):  
Finite Element ◽  
Steam Turbine ◽  
Peak Stress ◽  
Turbine Rotor ◽  
Element Analysis ◽  
B Splines ◽  
Steam Turbine Rotor ◽  
Spline Curves ◽  
Python Scripting ◽  
Gradient Based

An Alstom tool is described for the automated and simultaneous design optimisation of 2 and 4-hook T-root grooving of multiple steam turbine rotor stages in order to minimise the peak stress. The finite element axisymmetric thermal-stress calculation is performed with Abaqus in a few hours on modest hardware. The tool embeds Python scripting to facilitate the rotor groove model definition and meshing within Abaqus/CAE, with emphasis placed on minimising the effort for the initial setup. Rotor groove shapes are described with B-splines, maintained and modified within the in-house tool. Their shape is progressively refined as directed by a hybrid evolutionary-gradient based optimisation engine in order to achieve the minimum stress objective. In the region of highest stress, the groove boundary shape adjusts as the optimisation proceeds to conform to the local contours of stress. Application to a low pressure steam turbine rotor demonstrates comparable or lower stresses with this tool compared to those from manual expert optimisation. The method can be readily extended to other geometric entities on the rotor described with B-spline curves, e.g. cavities, seals.

scholarly journals DETERMINATION OF STRESS CONCENTRATION FACTORS OF A STEAM TURBINE ROTOR USING FINITE ELEMENT ANALYSIS

1970 ◽  
Vol 40 (2) ◽  
pp. 137-141
Author(s):  
R. Nagendra Babu ◽  
K. V. Ramana ◽  
K. Mallikarjuna Rao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Steam Turbine ◽  
Turbine Rotor ◽  
Element Analysis ◽  
Steam Turbine Rotor ◽  
Fine Mesh ◽  
Concentration Factors ◽  
Stress Concentration Factors

Stress Concentration Factors are significant in machine design as it gives rise to localized stress when any change in the design of surface or abrupt change in the cross section occurs. Almost all machine components and structural members contain some form of geometrical or microstructural discontinuities. These discontinuities are very dangerous and lead to failure. So, it is very much essential to analyze the stress concentration factors for critical applications like Turbine Rotors. In this paper Finite Element Analysis (FEA) with extremely fine mesh in the vicinity of the blades of Steam Turbine Rotor is applied to determine stress concentration factors.Keywords: Stress Concentration Factors; FiniteElement Analysis; ANSYS.DOI: 10.3329/jme.v40i2.5355Journal of Mechanical Engineering, Vol. ME 40, No. 2, December 2009 137-141

On real-time creep damage prediction for steam turbine

2022 ◽  
pp. 014233122110689
Author(s):  
Yongjian Sun ◽  
Bo Xu
Keyword(s):  
Finite Element ◽  
Steam Turbine ◽  
Real Time ◽  
Creep Damage ◽  
Element Model ◽  
Turbine Rotor ◽  
Theoretical Research ◽  
Element Analysis ◽  
Damage Prediction ◽  
Time Calculation

In this paper, in order to solve the calculation problem of creep damage of steam turbine rotor, a real-time calculation method based on finite element model is proposed. The temperature field and stress field of the turbine rotor are calculated using finite element analysis software. The temperature data and stress data of the crucial positions are extracted. The data of temperature, pressure, rotational speed, and stress relating to creep damage calculation are normalized. A real-time creep stress calculation model is established by multiple regression method. After that, the relation between stress and damage function is analyzed and fitted, and creep damage is calculated in real-time. A creep damage real-time calculation system is constructed for practical turbine engineering. Finally, a numerical simulation experiment is designed and carried out to verify the effectiveness of this novel approach. Contributions of present work are that a practical solution for real-time creep damage prediction of steam turbine is supplied. It relates the real-time creep damage prediction to process parameters of steam turbine, and it bridges the gap between the theoretical research works and practical engineering.

Effect of Steam Turbine Rotor Notch Fillet Radius on Stress and Deformation

2013 ◽  
Vol 860-863 ◽  
pp. 1770-1781
Author(s):  
Dong Mei Ji ◽  
M. H. Herman Shen ◽  
Shi Hua Yang ◽  
Gang Xia
Keyword(s):  
Finite Element ◽  
Thermal Stress ◽  
Finite Element Model ◽  
Steam Turbine ◽  
Element Model ◽  
Turbine Rotor ◽  
Critical Value ◽  
Steam Turbine Rotor ◽  
Fillet Radius ◽  
Start Up

A thorough investigation on the effect of a 320MW steam turbine rotor notch fillet radius on thermal and mechanical stresses during start up is presented. The approach consists of a shape design and analysis procedure which incorporates a finite element model. The finite element model is used to characterize the radius of the rotor notch fillet for ensuring the designed thermal and mechanical stress state/pattern and associated deflection during start-up. The results indicate that the notch fillet radius r has significant impact on the total stress of the rotor, in particular on thermal stress. It is determined that the thermal stress is decreased as the notch fillet radius r increases to a critical value. However, the thermal stress becomes saturated as the radius is increased to values larger than the critical value. The results also indicate that the rotor notch fillet radius has little effect on the deflection of the rotor during start-up. This investigation could be very useful to designers for construction of the design guidelines for steam turbine rotors.

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

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.

scholarly journals On the creep fatigue and creep rupture behaviours of 9–12% Cr steam turbine rotor

2019 ◽  
Vol 76 ◽  
pp. 263-278 ◽  
Author(s):  
Xuanchen Zhu ◽  
Haofeng Chen ◽  
Fuzhen Xuan ◽  
Xiaohui Chen
Keyword(s):  
Steam Turbine ◽  
Turbine Rotor ◽  
Creep Rupture ◽  
Steam Turbine Rotor ◽  
Creep Fatigue
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