A Three-Dimensional Simulation for Non-Isothermal Forging of a Steam Turbine Blade by the Thermoviscoplastic Finite Element Method

1993 ◽  
Vol 207 (4) ◽  
pp. 265-273 ◽  
Author(s):  
J-R Cho ◽  
N-K Lee ◽  
D-Y Yang
Keyword(s):  
Heat Transfer ◽  
Finite Element Method ◽  
Finite Element ◽  
Steam Turbine ◽  
Three Dimensional ◽  
Isothermal Forging ◽  
Isothermal Analysis ◽  
Steam Turbine Blade ◽  
Forging Load ◽  
Element Method

The study is concerned with the three-dimensional analysis for non-isothermal forging of a steam turbine blade by the thermoviscoplastic finite element method. The analysis includes deformation of the workpiece and heat transfer of the workpiece and the die. In the transient heat-transfer analysis, the finite element method is adopted for the workpiece, while the boundary element method is adopted for the die. The non-isothermal analysis is compared with the isothermal analysis as well as with the experimental results. The length of the forged blade increases by 20 per cent as compared to the initial billet, as confirmed by the deformed configuration of both the computation and experiment. The prediction for non-isothermal forging has been shown to be in good agreement with the experimental results from forging load, temperature and geometrical configurations. It has also been shown that consideration of nonisothermal conditions renders a better prediction of forging load.

Analysis of Heat Transfer and Straightening of Continuous Casting Slab Using 3D Finite Element Method

2011 ◽  
Vol 418-420 ◽  
pp. 1698-1702
Author(s):  
Qing Guo Liu ◽  
Xing Zhong Zhang ◽  
Zheng Yi Jiang ◽  
Yan Chao Sun ◽  
Bao Jun Shi ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Finite Element Method ◽  
Finite Element ◽  
Strain Rate ◽  
Three Dimensional ◽  
Three Dimension ◽  
Element Analysis ◽  
Strain And Strain Rate ◽  
Three Dimensional Finite Element ◽  
Element Method

The straightening of curved slab results in a greater straightening strain. During the process of multi-point straightening, the peak value of the straightening strain rate will appear at each straightening point. If the strain rate is too large, the straightening cracks will appear. Solidification and heat transfer of a slab is analyzed and the generation of the solidified shell and the three-dimension temperature field of the slab are calculated by using three-dimensional finite element method (FEM). Based on the finite element analysis of five-point straightening of the curved slab, the strain and strain rate of each straightening point were obtained, which is a base of the analysis of straightening cracks.

Thermostructural Analysis of Steam Turbine in Prewarming Operation With Hot Air

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Piotr Łuczyński ◽  
Dennis Toebben ◽  
Lukas Pehle ◽  
Manfred Wirsum ◽  
Wolfgang F. D. Mohr ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Finite Element Method ◽  
Finite Element ◽  
Steam Turbine ◽  
Thermal Contact ◽  
Temperature Fields ◽  
Cooling Curve ◽  
Steam Turbines ◽  
Hot Air ◽  
Element Method

AbstractIn pursuit of flexibility improvements and extension of lifetime, a concept to prewarm steam turbines using hot air was developed. In order to further optimize the prewarming operation, an extensive numerical investigation is conducted to determine the time-dependent temperature and stress fields. In this work, the transient thermal and structural analyses of an IP 19-stage steam turbine in prewarming operation with hot air are presented. Based on the previous investigations, a hybrid finite element method (HFEM—numerical finite element method (FEM) and analytical) approach especially developed for this purpose is applied to efficiently calculate the solid body temperatures of a steam turbine in predefined prewarming scenarios. The HFEM model utilizes the Nusselt number correlations to describe the heat transfer between the hot air and the turbine components in the flow channel. These correlations were developed based on unsteady conjugate heat transfer (CHT) simulations of multistage turbine models. In addition, most of the thermal energy in turbine prewarming operation is transferred through vanes and blades. Therefore, the HFEM approach considers the thermal contact resistance (TCR) on the surfaces between vanes/casing and blades/rotor. After the calibration of the HFEM model with experimental data based on measurements of the natural cooling curve, the prewarming processes for different prewarming scenarios are simulated. Subsequently, the obtained temperature fields are imported to an FEM model in order to conduct a structural analysis, which, among other variables, includes the values and locations of highest stresses and displacements.

scholarly journals Optimization of Air Conditioner (AC) Use on a Room with Finite Element Method

2021 ◽  
Vol 10 (1) ◽  
pp. 14-20
Author(s):  
Lamtiur Simbolon
Keyword(s):  
Heat Transfer ◽  
Finite Element Method ◽  
Finite Element ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Linear Interpolation ◽  
Computer Assisted ◽  
Air Conditioner ◽  
The Finite Element Method ◽  
Element Method

The process of working Air Conditioner (AC) in the cooling of a room is a process of heat transfer. This study aims to find out how the distribution of temperature in a room contained AC in it which is solved by implementing the finite element method on the energy transfer equation which is the differential equation used for heat transfer. In the finite element method, the flow field is broken down into a set of small fluid elements (domain discretization). In this study the researcher describes the space in three-dimensional space (3D), then selected linear interpolation function for 3D element, and decreases the matrix and vector elements by Galerkin method to obtain Global equation. Results from computer-assisted studies show the temperature distribution in the room.

Last Stage Blade Coupled Shaft Torsional Vibration Analysis of 1000 MW Steam Turbine Generator Set by a Reduced 3D Finite Element Method

2014 ◽  
Author(s):  
Zi-Li Xu ◽  
Baitong Dou ◽  
Xiaoping Fan ◽  
Yu Fang ◽  
Shouhong Cao ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Steam Turbine ◽  
Synthesis Method ◽  
Three Dimensional ◽  
Coupled Vibration ◽  
Turbine Generator ◽  
Last Stage ◽  
Three Dimensional Finite Element ◽  
Element Method

To increase output and efficiency of steam turbine, long or ultra-long blades are used for last stage blades of low pressure rotors. The application of long blades enhance the coupled effect between the shaft torsional vibration and nodal diameter zero umbrella vibration mode of shrouded blade. In order to precisely calculate the shaft-blade coupled vibration characteristics for large steam turbine generator sets, a reduced method consisted of the three dimensional finite element method and the component mode synthesis method is studied. The study shows that the precision of the reduction method can be guaranteed if the maximum frequency of high order mode used in the coordinate transformation matrix of substructure is higher than 5 times of the maximum frequency of the whole system that one hopes to calculate. The last-stage, the next to last stage blades, and the whole shaft of a 1000MW steam turbine generator set are described by the three dimensional finite element method. The degrees of freedom of the whole system are reduced by using the component mode synthesis method. The coupled vibration of the steam turbine generator set is computed. The vibration of the shaft neglecting the coupled effect is also calculated, and only the moment of inertia of disk-blades is considered. The results by two models are compared with each other. The results show that there exist 4 extra torsional coupled vibration modes when the structural flexibility influence of last-stage and the next to last stage blades is considered.

Towards Predicting Relative Belt Edge Endurance With the Finite Element Method

1990 ◽  
Vol 18 (4) ◽  
pp. 216-235 ◽  
Author(s):  
J. De Eskinazi ◽  
K. Ishihara ◽  
H. Volk ◽  
T. C. Warholic
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Shear Deformations ◽  
Element Analysis ◽  
Vertical Loading ◽  
Predicted Values ◽  
Element Method

Abstract The paper describes the intention of the authors to determine whether it is possible to predict relative belt edge endurance for radial passenger car tires using the finite element method. Three groups of tires with different belt edge configurations were tested on a fleet test in an attempt to validate predictions from the finite element results. A two-dimensional, axisymmetric finite element analysis was first used to determine if the results from such an analysis, with emphasis on the shear deformations between the belts, could be used to predict a relative ranking for belt edge endurance. It is shown that such an analysis can lead to erroneous conclusions. A three-dimensional analysis in which tires are modeled under free rotation and static vertical loading was performed next. This approach resulted in an improvement in the quality of the correlations. The differences in the predicted values of various stress analysis parameters for the three belt edge configurations are studied and their implication on predicting belt edge endurance is discussed.

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