Advanced Materials Research Vols. 712-715

Abstract: Based on entropy technology, combined with fuzzy evaluation method, five experiments parameters evaluation of high speed wire-cut electrical discharge machining (WEDM-HS) are done,which evaluation results are in accordance with process analysis results, verify correction of evaluation method, and provide some theory basis for fuzzy evaluation and optimization of machining process.

Abstract: With low permeability reservoir into the scale of development, well test gets further attention and application. But in the field application, well test interpretation model, interpretation methods of choice still exist more problems in low permeability and extra-low permeability reservoir. In this paper, with low permeability reservoir build-up well test process, we established mathematical model of the low permeability reservoir build-up well test, and deduce the analytical solution of the mathematical model. Using the deduced theoretical formula, analyze the impact factors. The results of the study show that: well storage coefficient, inner zone permeability and outer zone permeability are sensitive factors; skin coefficient is not sensitive factors.

Abstract: Experimental study on the combustion and emission performance of turbocharged lean-burned CNG engine by the ignition time. Speed of the engine is 1340r/min,1615r/min,1890r/min,with 25%, 50%,75%,100% load. Results show that when keeping other combustion boundary conditions unchanged, the effect of the ignition time on engine output torque and CH4 is little,the effect changes as speed varies from low speed and load conditions to higher level.However,the effects of ignition time on NOx emissions are huge.With the backward changes of the ignition time,NOx emissions has decreased significantly.

Abstract: The influence of anode current collector layer (ACCL) thickness is studied for different ACCL porosity and different pitch width. The results shows conclusively that the output current density depends strongly on the ACCL thickness and a suitable choice of the ACCL thickness is very important for the high performance of a SOFC stack. Furthermore, the optimal ACCL thickness is found to be dependent linearly on the pitch width and the parameters for the linearity are given.

Abstract: Three dimensional transient numerical simulation on cylinder flow field of 4B26 diesel was done by AVL FIRE. Detailed flow field structure of diesel cylinder was calculated. The typical swirl flow and squish flow were established in 4B26 diesel engine chamber. swirl flow and squish flow can increase the fuel and air mixing rate, and can improve diesel combustion and can reduce emissions of pollutants. Oil beam could accelerate the air around it.

Abstract: In the research of buoy wave power devices, earlier studies have indicated that the vertical cylindrical can absorb the most power from wave by comparing the loading conditions of several buoys (e.g.cuboid, vertical cylindrical, horizontal cylindrical, sphere, and so on) using the Froude-Krylov theory. However, it is not argued the motion response of buoys with the same basal area and the different basal shapes. In this paper, buoys with the same basal area and the different basal shapes are investigated by the mean of simulation. There are two modes for the floating system, one is with mooring line and the other is without. In both cases, the motions in horizontal (x axis) and vertical (z axis) direction will be studied.

Abstract: Based on the fact of low single seed plant rate, high seed damaged rate and low seed adaptability for conventional and mechanistic precision seed-metering device, a new belt type of seed-metering device was designed (patent No.20101020638.7). both of the 1/4 spherical shape and its size was first established by analyzing the working process of the seed-metering combination the material character of the tested corn seed, and the structure size 6mmX6mm of the seed scoop of this type of seed-metering was then determined by the frame test in agricultural lab, which was tested to own the good work performance. At last, the working adaptability tests were operated, the conclusion showed that the following character indexes were single seed plant rate 98.6%, repeated plant rate 6.3%, leakage plant rate 0.8% and seed damaged rate 0.05% when the size of seed-scoop is 8mmX12mm and the belt speed is1.05 m/s.

Abstract: Synthesis load model considering distribution network connection can simulate actual performance of power grid, however, the model structure is quiet complicated, and distinguished result of parameters is not unique. To solve the above-mentioned problems, this paper proposes a load model parameters identification method based on sensitivity analysis by analysis the structure of synthesis load model with distribution network connection, The simulation results show the model is effective and proper, and the method can reduce computation and save computing time.

Abstract: The microporous on spinneret has the characteristics of high precision, small pore size and large quantity. Spinneret microporous finishing operation is mainly used for removing the burr formed on the spinneret silk surface after micropores drilling and punching. The burrs seriously affect the quality of the spinning fibers. Micropore spinneret finishing plays a vital role in improving the quality of processing micropore. This paper introduces a system consisting of the spinneret micropore fine machine,then focuses on fine machine positioning system and proposes a high-precision positioning method of the microporous.

Abstract: A mathematical analytic expression is proposed to calculate the eddy electromagnetic fields induced by rotating simplified propeller model based on Faradays law. The simulation of this model gives the distribution characteristics of the induced electric field signals. The longitudinal characteristics and transit characteristics shows the transit characteristics is discrete and has apparent characteristics.