scholarly journals Application of Rapid Prototyping Technology in the Manufacturing of Turbine Blade With Small Diameter Holes

2018 ◽  
Vol 25 (s1) ◽  
pp. 119-123 ◽  
Author(s):  
Mariusz Deja ◽  
Michał Dobrzyński ◽  
Paweł Flaszyński ◽  
Jacek Haras ◽  
Dawid Zieliński
Keyword(s):  
Rapid Prototyping ◽  
Turbine Blade ◽  
Cross Sections ◽  
Turbine Blades ◽  
Small Diameter ◽  
Direct Metal Laser Sintering ◽  
Longitudinal Vortices ◽  
Micro Holes ◽  
Discharge Method ◽  
Blade Model

Abstract The article presents the possibilities++ of using Rapid Prototyping (RP) technology in the manufacturing of turbine blades with small diameter holes. The object under investigation was gas turbine blade with small diameter cooling holes and holes for generating longitudinal vortices. A turbine blade model was produced by means of Direct Metal Laser Sintering (DMLS) technology and subsequently validated in terms of detection and accuracy of the obtained holes. The application of the computer tomography and digital radiography technique resulted in obtaining a series of cross-sections of the turbine blade model with a series of holes. Particular attention was pointed out at the investigation of the locations of micro-holes with a diameter of 0.3 mm. It turned out that it was impossible to make such small holes by the RP method. In the following part the results of the study on the possibilities of making the micro-holes using electrical discharge method have been presented. In addition, proposition of further works such as the development of the considerations and issues discussed in this article, has been offered.

Pretwist and Shear Flexibility in the Vibrations of Turbine Blades

1985 ◽  
Vol 52 (2) ◽  
pp. 409-415 ◽  
Author(s):  
S. Krenk ◽  
O. Gunneskov
Keyword(s):  
Steam Turbine ◽  
Turbine Blade ◽  
Wall Thickness ◽  
Cross Sections ◽  
Strain Energy ◽  
Turbine Blades ◽  
Beam Element ◽  
Shear Stresses ◽  
Warping Function ◽  
Steam Turbine Blade

A theory is developed for pretwisted beams with finite shear flexibility. The effect of pretwist is accounted for via the axial derivative of the St. Venant warping function. The shear flexibility relies on a decomposition of the shear stresses into torsion and shear contributions, and the normalized strain energy of the latter is expressed in terms of the shear flexibility tensor. An explicit approximation for the shear flexibility tensor is derived for cross sections of moderate wall thickness. A special Legendre transformation is used to obtain a consistent discretization, which is then cast in the form of a finite beam element. The accuracy of the method is illustrated by comparison with experimental results for a steam turbine blade, and the effects of pretwist and shear flexibility are discussed.

scholarly journals Turbine Blade Three-Wavelength Radiation Temperature Measurement Method Based on Reflection Error Correction

2021 ◽  
Vol 11 (9) ◽  
pp. 3913
Author(s):  
Kaifeng Zheng ◽  
Jinguang Lü ◽  
Yingze Zhao ◽  
Jin Tao ◽  
Yuxin Qin ◽  
...  
Keyword(s):  
Temperature Measurement ◽  
Turbine Blade ◽  
Measurement Method ◽  
Turbine Blades ◽  
Target Surface ◽  
Maximum Error ◽  
Radiation Temperature ◽  
Average Error ◽  
Real Surface ◽  
Wavelength Radiation

The turbine blade is a key component in an aeroengine. Currently, measuring the turbine blade radiation temperature always requires obtaining the emissivity of the target surface in advance. However, changes in the emissivity and the reflected ambient radiation cause large errors in measurement results. In this paper, a three-wavelength radiation temperature measurement method was developed, without known emissivity, for reflection correction. Firstly, a three-dimensional dynamic reflection model of the turbine blade was established to describe the ambient radiation of the target blade based on the real surface of the engine turbine blade. Secondly, based on the reflection correction model, a three-wavelength radiation temperature measurement algorithm, independent of surface emissivity, was proposed to improve the measurement accuracy of the turbine blade radiation temperature in the engine. Finally, an experimental platform was built to verify the temperature measurement method. Compared with three conventional colorimetric methods, this method achieved an improved performance on blade temperature measurement, demonstrating a decline in the maximum error from 6.09% to 2.13% and in the average error from 2.82% to 1.20%. The proposed method would benefit the accuracy in the high-temperature measurement of turbine blades.

The Research on Macro Charged Jet Phenomenon and its Orderly Collection

2011 ◽  
Vol 121-126 ◽  
pp. 1156-1159
Author(s):  
Yuan Yuan Liu ◽  
Qing Wei Li ◽  
Qing Xi Hu ◽  
Chang Juan Jing ◽  
Qiang Gao Wang
Keyword(s):  
Rapid Prototyping ◽  
Influence Factors ◽  
Small Diameter ◽  
Rotating Disk ◽  
Linear Motion ◽  
Injection Speed ◽  
Collection Device ◽  
Forming Precision

Macro charged jet molding combines with Rapid Prototyping and electrospinning together, it solved the problem of insufficient forming precision with RP molding and the difficulty of collection with electrospinning which caused by highly injection speed and small diameter. This article talks about Macro charged jet phenomena of PEO solution and its influence factors through experiment, detected diameter of the shoot fluid by using microscope, measured micro-injection speed by using the rotating disk with linear motion collection device, achieved orderly collection of Macro charged jet with different diameter and injection speed.

scholarly journals Thermal–Fluid–Solid Coupling Analysis on the Temperature and Thermal Stress Field of a Nickel-Base Superalloy Turbine Blade

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3315
Author(s):  
Liuxi Cai ◽  
Yao He ◽  
Shunsen Wang ◽  
Yun Li ◽  
Fang Li
Keyword(s):  
Thermal Stress ◽  
Temperature Gradient ◽  
Turbine Blade ◽  
Turbine Blades ◽  
Nickel Base Superalloy ◽  
Barrier Coating ◽  
Thermal Stress Field ◽  
Nickel Base ◽  
Stress Damage ◽  
Superalloy Turbine Blade

Based on the establishment of the original and improved models of the turbine blade, a thermal–fluid–solid coupling method and a finite element method were employed to analyze the internal and external flow, temperature, and thermal stress of the turbine blade. The uneven temperature field, the thermal stress distribution characteristics of the composite cooling turbine blade under the service conditions, and the effect of the thickness of the thermal barrier coating (TBC) on the temperature and thermal stress distributions were obtained. The results show that the method proposed in this paper can better predict the ablation and thermal stress damage of turbine blades. The thermal stress of the blade is closely related to the temperature gradient and local geometric structure of the blade. The inlet area of the pressure side-platform of the blade, the large curvature region of the pressure tip of the blade, and the rounding between the blade body and the platform on the back of the blade are easily damaged by thermal stress. Cooling structure optimization and thicker TBC thickness can effectively reduce the high temperature and temperature gradient on the surface and inside of the turbine blade, thereby reducing the local high thermal stress.

Studies on Determination of Natural Frequencies of Industrial Turbine Blades

1995 ◽  
Author(s):  
Mahesh M. Bhat ◽  
V. Ramamurti ◽  
C. Sujatha
Keyword(s):  
Steam Turbine ◽  
Dynamic Behavior ◽  
Turbine Blade ◽  
Natural Frequencies ◽  
Complex Structure ◽  
Turbine Blades ◽  
Blade Root ◽  
Steam Turbine Blade ◽  
Manufacturing Tolerances

Abstract Steam turbine blade is a very complex structure. It has geometric complexities like variation of twist, taper, width and thickness along its length. Most of the time these variations are not uniform. Apart from these geometric complexities, the blades are coupled by means of lacing wire, lacing rod or shroud. Blades are attached to a flexible disc which contributes to the dynamic behavior of the blade. Root fixity also plays an important role in this behavior. There is a considerable variation in the frequencies of blades of newly assembled turbine and frequencies after some hours of running. Again because of manufacturing tolerances there can be some variation in the blade to blade frequencies. Determination of natural frequencies of the blade is therefore a very critical job. Problems associated with typical industrial turbine bladed discs of a 235 MW steam turbine are highlighted in this paper.

Water Droplet Erosion Life Prediction Method for Steam Turbine Blade Materials Based on Image Recognition and Machine Learning

2020 ◽  
Author(s):  
Zheyuan Zhang ◽  
Tianyuan Liu ◽  
Di Zhang ◽  
Yonghui Xie
Keyword(s):  
Machine Learning ◽  
Turbine Blade ◽  
Image Recognition ◽  
Water Droplet ◽  
Turbine Blades ◽  
Prediction Method ◽  
Remaining Useful Life ◽  
Feature Maps ◽  
Water Droplet Erosion ◽  
Data Processing Method

Abstract In this paper, a method for predicting remaining useful life (RUL) of turbine blade under water droplet erosion (WDE) based on image recognition and machine learning is presented. Using the experimental rig for testing the WDE characteristics of materials, the morphology pictures of specimen surface at different times in the process of WDE are collected. According to the data processing method of ASTM-G73 and the cumulative erosion-time curves, the WDE stages of materials is quantitatively divided and the WDE life coefficient (ζ) is defined. The life coefficient (ζ) could be used to calculate the RUL of turbine blades. One convolutional neural network model and three machine learning models are adopted to train and predict the image dataset. Then the training process and feature maps of the Resnet model are studied in detail. It is found that the highest prediction accuracy of the method proposed in this paper can be 0.949, which is considered acceptable to provide reference for turbine overhaul period and blade replacement time.

Optimization of Supersonic Axial Turbine Blades Based on Surrogate Models

2020 ◽  
Author(s):  
Markus Waesker ◽  
Bjoern Buelten ◽  
Norman Kienzle ◽  
Christian Doetsch
Keyword(s):  
Reynolds Number ◽  
Turbine Blade ◽  
Surrogate Model ◽  
Cfd Simulation ◽  
Turbine Blades ◽  
Energy System ◽  
Design Parameters ◽  
Blade Design ◽  
Axial Turbine ◽  
Velocity Coefficient

Abstract Due to the transition of the energy system to more decentralized sector-coupled technologies, the demand on small, highly efficient and compact turbines is steadily growing. Therefore, supersonic impulse turbines have been subject of academic research for many years because of their compact and low-cost conditions. However, specific loss models for this type of turbine are still missing. In this paper, a CFD-simulation-based surrogate model for the velocity coefficient, unique incidence as well as outflow deviation of the blade, is introduced. This surrogate model forms the basis for an exemplary efficiency optimization of the “Colclough cascade”. In a first step, an automatic and robust blade design methodology for constant-channel blades based on the supersonic turbine blade design of Stratford and Sansome is shown. The blade flow is fully described by seven geometrical and three aerodynamic design parameters. After that, an automated numerical flow simulation (CFD) workflow for supersonic turbine blades is developed. The validation of the CFD setup with a published supersonic axial turbine blade (Colclough design) shows a high consistency in the shock waves, separation zones and boundary layers as well as velocity coefficients. A design of experiments (DOE) with latin hypercube sampling and 1300 sample points is calculated. This CFD data forms the basis for a highly accurate surrogate model of supersonic turbine blade flow suitable for Mach numbers between 1.1 and 1.6. The throat-based Reynolds number is varied between 1*104 and 4*105. Additionally, an optimization is introduced, based on the surrogate model for the Reynolds number and Mach number of Colclough and no degree of reaction (equal inlet and outlet static pressure). The velocity coefficient is improved by up to 3 %.

Innovative Design, Structural Optimization and Additive Manufacturing of New-Generation Turbine Blades

2021 ◽  
pp. 1-31
Author(s):  
Lorenzo Pinelli ◽  
Andrea Amedei ◽  
Enrico Meli ◽  
Federico Vanti ◽  
Benedetta Romani ◽  
...  
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Structural Optimization ◽  
Turbine Blade ◽  
Turbine Blades ◽  
Topological Optimization ◽  
Mode Shapes ◽  
Structural Topology Optimization ◽  
Structural Topology ◽  
New Generation

Abstract The need for high performances is pushing the complexity of mechanical design at very high levels, especially for turbomachinery components. Structural topology optimization methods together with additive manufacturing techniques for high resistant alloys are considered very promising tools, but their potentialities have not been deeply investigated yet for critical rotating components like new-generation turbine blades. This research work proposes a methodology for the design, the optimization and the additive manufacturing of extremely stressed turbomachinery components like turbine blade-rows. The presented procedure pays particular attention to important aspects of the problems as fluid-structure interactions and fatigue of materials, going beyond the standard structural optimization approaches found in the literature. The numerical procedure shows robustness and efficiency, making the proposed methodology a good tool for rapid design and prototyping, and for reducing the design costs and the time-to-market typical of these mechanical elements. The procedure has been applied to a low-pressure turbine rotor to improve the aeromechanical behavior while keeping the aerodynamic performance. From the original geometry, mode-shapes, forcing functions and aerodynamic damping have been numerically evaluated and are used as input data for the following topological optimization. Finally, the optimized geometry has been verified in order to confirm the improved aeromechanical design. After the structural topology optimization, the final geometries provided by the procedure have been then properly rendered to make them suitable for additive manufacturing. Some prototypes of the new optimized turbine blade have been manufactured to be tested in terms of fatigue.

Machine Learning Aided Prediction of Rain Erosion Damage on Wind Turbine Blade Sections

2021 ◽  
Author(s):  
Alessio Castorrini ◽  
Paolo Venturini ◽  
Fabrizio Gerboni ◽  
Alessandro Corsini ◽  
Franco Rispoli
Keyword(s):  
Wind Turbine ◽  
Turbine Blade ◽  
Energy Production ◽  
Turbine Blades ◽  
Wind Farms ◽  
Wind Turbine Blade ◽  
Wind Turbine Blades ◽  
Coating Materials ◽  
Erosion Modelling ◽  
Rain Erosion

Abstract Rain erosion of wind turbine blades represents an interesting topic of study due to its non-negligible impact on annual energy production of the wind farms installed in rainy sites. A considerable amount of recent research works has been oriented to this subject, proposing rain erosion modelling, performance losses prediction, structural issues studies, etc. This work aims to present a new method to predict the damage on a wind turbine blade. The method is applied here to study the effect of different rain conditions and blade coating materials, on the damage produced by the rain over a representative section of a reference 5MW turbine blade operating in normal turbulence wind conditions.

scholarly journals Tuning of Turbine Blades: A Theoretical Approach

1982 ◽  
Author(s):  
P. Gudmundson
Keyword(s):  
Perturbation Method ◽  
Turbine Blade ◽  
Theoretical Approach ◽  
Turbine Blades ◽  
Rectangular Beam ◽  
Resonance Frequencies ◽  
Geometrical Change

A perturbation method is described which predicts the changes in eigenfrequencies resulting from geometrical changes of a structure. This dependence is represented by dimensionless functions, one for each eigenfrequency, which vary over the surface of the structure. The functions are presented for each eigenfrequency as isoline plots. An easily estimated integration of these functions allows one to predict a geometrical change which results in a desired change in the resonance frequencies. The method was applied to a turbine blade and a rectangular beam. For the turbine blade isoline plots are presented for the first five eigenfrequencies. Eigenfrequency changes up to 8 percent were modeled accurately.

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