scholarly journals Surface Fitting for non-Grid Data from in-Situ Measuring Systems of Aero-engine Blade

2020 ◽  
Vol 206 ◽  
pp. 03023
Author(s):  
Qing Mao ◽  
Sen Wang ◽  
Shugui Liu

High machining accuracy of aero-engine blade largely determines the carrying capacity, endurance, acceleration and the dynamic performance of the aero-engine, so a reliable machining error inspection and evaluation technique is imperative. In order to give a reliable error evaluation, the non- uniform rational B-spline (NURBS) technique is adopted to reconstruct the surface within a specified accuracy. Usually, data points measured from aero-engine blade are non-grid data in situ measuring systems. To overcome the difficulty of NURBS surface fitting from non-grid data, a new method based on data conversion is proposed, in which chord length parameterization and uniform parameter sampling are combined together to realize the data convertation, and subsequently hierarchical fitting strategy is applied to finish the NURBS surface reconstruction. The way proposed for data conversion is easy to realize, and by which gemetrical features of original measured data are also reserved well, which make the whole method outstanding in low time cost. Experimental results show that the method is fast, effective. The source code has been implemented in VC++, while the resulting pictures are constructed in Matlab with the obtained control points, knot vectors, and the orders.

2010 ◽  
Vol 121-122 ◽  
pp. 893-899 ◽  
Author(s):  
Zhi Yong Li ◽  
Hua Ji ◽  
Hong Li Liu

Because the process of blade in electrochemical machining(EMC) can be effected by many factors, such as blade shapes, machining electrical field, electrolyte fluid field and anode electrochemical dissolution, different ECM machining parameters maybe result in great affections on blade machining accuracy. Regard some type of aero-engine blade as research object, five main machining parameters, applied voltage, initial machining gap, cathode feed rate, electrolyte temperature and pressure difference between electrolyte inlet and outlet, have been evaluated and optimized based on BP neural network technique. From 3125 possible machining parameter combinations, 657 optimized parameter combinations are discovered. To verify the validity of the optimized ECM parameter combination, a serial of machining experiments have been conducted on an industrial scale ECM machine, and the experiment results demonstrates that the optimized ECM parameter combination not only can satisfy the manufacturing requirements of blade fully but has excellent ECM process stability.


2013 ◽  
Vol 567 ◽  
pp. 67-72 ◽  
Author(s):  
Zhi Yong Li ◽  
Zong Wei Niu ◽  
Li Li

Because the process of blade in electrochemical machining(EMC) can be effected by many factors, such as blade shapes, machining electrical field, electrolyte fluid field and anode electrochemical dissolution, different ECM machining parameters maybe result in great affections on blade machining accuracy. Regard some type of aero-engine blade as research object, a great deal of ECM machining parameter combination which probably result in machining failure can be eliminated based on BP neural network firstly. Furthermore, the optimized ECM machining parameter combination has been discovered. To verify the validity of the optimized ECM parameter combination, a serial of machining experiments have been conducted on an industrial scale ECM machine, and the experiment results demonstrates that the optimized ECM parameter combination not only can satisfy the manufacturing requirements of blade fully but has excellent ECM process stability.


Author(s):  
Guijian Xiao ◽  
Yi He ◽  
Yun Huang ◽  
Shui He ◽  
Wenxi Wang ◽  
...  

Researches show that surface with bionic structure plays an important role in improving the aerodynamic performance on aero engine parts. Belt grinding, a popular method to process titanium alloy parts such as aero-engine blade, is also found that it can be used to obtain bionic microstructure through special grinding method and parameters. In order to explore the performance of bionic microstructure processed by belt grinding and its effects on airflow dynamics, several groups of simulation and an experiment are carried out in this paper. Firstly, the mechanism of drag reduction of bionic microstructure is discussed. It shows that the effect of drag reduction of bionic microstructure is related to protrusion height, which is related to the shape and size of the bionic microstructure. Then, three groups of typical belt grinding bionic microstructure are set up. In addition, the drag reduction values are calculated in CFD simulation. The results are analyzed and discussed. Further, to verify the airflow dynamics of drag reduction of belt grinding bionic microstructure, an experiment of aero-engine blade is carried out. Finally, the effects of airflow dynamic performance of blade with belt grinding bionic microstructure are obtained in CFD simulation. In general, the shape of wave ribs, compared to V-ribs and trapezoidal ribs, has the best performance in drag reduction. To a certain extent, the improvement of airflow dynamic performance is higher with the increasing of the size of bionic microstructure, which suggests lower feed rate and higher grinding pressure for bionic structure.


2018 ◽  
Vol 764 ◽  
pp. 225-234 ◽  
Author(s):  
Zhi Qiang Zhao ◽  
Zhi Gang Ma ◽  
Yue Tao Liu ◽  
Xiao Long Wu ◽  
Hun Guo

Utilizing all-direction electrochemical machining (ECM) for super-thin twist aero-engine, feed angle of tool cathode and blade fixture angle are investigated and optimized in this study. The most optimal combination of the two angles (oblique feed angle of tool cathode and fixture angle of blade stock) is selected from all 65341 angle combinations. Moreover, the affections of the optimized angle combination on machining error distribution between blade shape and plate are concentrated. The analysis and experimental results demonstrate that the optimized angle combination can satisfy the machining requirements of blade shape and error distribution of blade shape and plate.


2010 ◽  
Vol 135 ◽  
pp. 418-423 ◽  
Author(s):  
Zhi Yong Li ◽  
Zong Wei Niu

Because the process of blade in electrochemical machining(EMC) can be effected by many factors, such as blade shapes, machining electrical field, electrolyte fluid field and anode electrochemical dissolution, different ECM machining parameters maybe result in great affections on blade machining accuracy. Regard some type of aero-engine blade as research object, five main machining parameters, applied voltage, initial machining gap, cathode feed rate, electrolyte temperature and pressure difference between electrolyte inlet and outlet, have been evaluated and optimized based on BP neural network technique. From 3125 possible machining parameter combinations, 657 optimized parameter combinations are discovered. Furthermore, the final optimized ECM process parameters have been obtained. To verify the validity of the optimized ECM parameter combination, a serial of machining experiments have been conducted on an industrial scale ECM machine, and the experiment results demonstrates that the optimized ECM parameter combination not only can satisfy the manufacturing requirements of blade fully but has excellent ECM process stability.


Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4863
Author(s):  
Victor Dyomin ◽  
Alexandra Davydova ◽  
Igor Polovtsev ◽  
Alexey Olshukov ◽  
Nikolay Kirillov ◽  
...  

The paper presents an underwater holographic sensor to study marine particles—a miniDHC digital holographic camera, which may be used as part of a hydrobiological probe for accompanying (background) measurements. The results of field measurements of plankton are given and interpreted, their verification is performed. Errors of measurements and classification of plankton particles are estimated. MiniDHC allows measurement of the following set of background data, which is confirmed by field tests: plankton concentration, average size and size dispersion of individuals, particle size distribution, including on major taxa, as well as water turbidity and suspension statistics. Version of constructing measuring systems based on modern carriers of operational oceanography for the purpose of ecological diagnostics of the world ocean using autochthonous plankton are discussed. The results of field measurements of plankton using miniDHC as part of a hydrobiological probe are presented and interpreted, and their verification is carried out. The results of comparing the data on the concentration of individual taxa obtained using miniDHC with the data obtained by the traditional method using plankton catching with a net showed a difference of no more than 23%. The article also contains recommendations for expanding the potential of miniDHC, its purpose indicators, and improving metrological characteristics.


2018 ◽  
Vol 764 ◽  
pp. 133-141 ◽  
Author(s):  
Zhi Yong Li ◽  
Qing Wei Cui ◽  
Bin Chen ◽  
Ji Xu ◽  
Hun Guo

The process parameters of fundamental electroforming solution were optimized firstly. Furthermore, some pure copper electroforming samples were prepared in the condition of different nana La2O3 addition quantity. Three main material properties evaluated. In addition, the EDM machining experiments were conducted to verify the characteristics of electrical corrosion resistance resulting from the prepared copper tube electroforming samples for cooling hole of Inconel718 nickel alloy. EDM experimental results demonstrate that copper electroforming layer with grain size 15.9μm, microhardness 98.2HV, with 1.2g/L addition quantity of nana La2O3, and its electrode loss rate decrease 13.29% and 7.26% than pure copper and copper electroforming layer without nana La2O3 addition respectively.


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