Advanced Materials Research Vol. 680

Abstract: The paper describe the imbalance loads、single phase short circuit to ground or bidirectional circuit to ground in the grid can bring unbalanced fault and the asymmetrical grid voltage. In the DFIG the faint imbalance stator voltage can bring much imbalance current, electromagnetic torque and active power would fluctuate. The DFIG performance will deteriorate, the central reason is the negative sequence component of the stator voltage、current with the asymmetrical grid voltage. The comparison between evaluated results and simulation of stator、rotor transient currents when the grid voltage drops is similar much.

Abstract: To a particular inline-four high-speed gasoline engine as the research object, main bearing lubrication analysis model of four-cylinder engine is based on AVL-Excite Power Unit software and couples the mechanical dynamics with lubricating fluid dynamics. On the basis of this model, we are focusing on the influence of parameters such as grease groove width on the engine main bearing lubrication performance. According to the analysis of simulation results on the minimum film thickness and maximum film pressure, and combined with the analysis report of disassembling the engine, it is easy to know why bearing bushes wear and provide the basis for the optimized design of the crankshaft main bearing. Improving design of the main bearing is more useful for operating requirement.

Abstract: As the important part of the internal-combustion engine, cylinder head bears high thermal loads and mechanical loads. In order to analyse the merits or defects of cylinder head cooling system , built the 3-D model of cylinder head, and analysed the heat transfer processes between cylinder head and cooling water by fluid-solid coupled simulation in STAR-CCM+. The pressure nephograms and velocity vector of cooling water in the water jacket, and the whole temperature distributions of cylinder head were acquired. And analysed separately the temperature fields of fire power faces and exhaust passages which were under high heat loads .According to the analysis results , the structrue of cylinder head water jacket was evaluated and corresponding suggestions was put forward.

Abstract: This paper proposes a reasonable methodology applied in classification and quantification techniques based on the voltammetric electronic tongue. We designed voltammetric electronic tongue oil sample pretreatment system with petroleum ether organic solvent. Through three-electrode system and cyclic voltammetry method processing blending soybean oil sample to get waveform output. Extracting crest methods as its feature extraction Pattern recognition use kernel principal component analysis and factor analysis blending on a different level of soybean oil, Partial Least Square (PLS) techniques was applied for data management and prediction models building, the prediction models are the blending ratio, the results show that voltammetric electron tongue can distinguish the quality of soybean oil.

Abstract: The disadvantages of infrared image are low resolution, bad stereoscopic sense, fuzzy image and low SNR, according to the application of infrared image in fault diagnosis of electronic power equipment, in this paper ,we make a comparative research on pre-processing technique of image de-noising and enhancement, and propose an infrared image enhancement algorithm based on platform histogram equalization combined with enhanced high-pass filtering, the algorithm can effectively improve the contrast by comparison, it is obvious to the noise effect, highlighting the objectives and details, and makes a good foundation for the subsequent target identification and fault diagnosis.

Abstract: In order to improve the accuracy of maintenance, repair and overhaul (MRO) description and the clarity of on-site guidance for aircraft MRO job card, a publishing method for aircraft 3D MRO job card based on aircraft 3D model was proposed. This method can show the disassembly and assembly simulation process with dynamic viewpoint navigation technology to conform to the observation habit of human, and separately show technical requirements from different MRO disciplines and operation tasks with multi-view 3D annotation method, and finally, transforms the MRO order into 3D portable job card file based on lightweight model and releases it to MRO site. The MRO instance of aircraft right wing shows that this method can generate intuitive, accurate and non-ambiguous MRO process description, improve the quality and efficiency of aircraft MRO.

Abstract: Researching on the influence of blast furnace tuyere under the condition of hot gas flow rate range of 60 ~240m / s by the method of using computational fluid dynamics. During the process of going through the tuyere, the tuyere cool the hot gas due to the cooling water inner it . At the same time, the more slow hot gas flow velocity is, the stronger cooling effect is, the greater energy is lost. Take this to hot air flow field of three dimensional numerical simulation, and discussed the reasonable air velocity interval, which can guarantee low thermal load and prevent a loss to larger energy .

Abstract: Paper electromagnetic drying technology is a new paper drying technology different from traditional steam drying. Today, environmental pressure deteriorating, energy crisis approaching, doing researches on paper electromagnetic drying technology has a special meaning, especially to high speed toilet paper machine which is truly needed and has a vast developmental potential. This thesis is based on electromagnetic dryer and steam dryer study. And the changes measured in the experiment at diverse temperatures and quantities in the experiment has shown a higher efficiency of electromagnetic drying technology than conventional steam drying technology.

Abstract: In this paper, a novel/well designed high speed/high precision nut air cooling ball screw system was developed to avoid thermal errors which affect the positioning accuracy and the temperature rise of ball screw. In order to discuss the effectiveness of the developed high speed/high precision nut air cooling ball screw system, a series of tests was done. As the results, it shows that the positioning accuracy will significantly improve with the use of the nut air cooling ball screw drive system shown in this paper.

Abstract: In order to calculate fatigue life of dump truck lifting mechanism’s structure components, a virtual prototyping model of lifting mechanism was built with Multi-body Dynamic Simulation Software ADAMS. The variation of applied force of lifting mechanism rod with lifting angle was obtained from dynamic analysis of lifting mechanism. A finite element (FEM) model of the rod was established using FEM Software MSC.PATRAN/NASTRAN, and its structural strength was analyzed. On this basis, S-N curve of the rod and linear cumulative damage law was combined to calculate the rod’s fatigue life with Fatigue Analysis Software MSC.Fatigue using nominal stress method. This study provided a reference for the design and improvement of the lifting mechanism.