Advanced Materials Research Vols. 1008-1009

Abstract: In this paper, The static strength analysis on the output of the two types of cylinder block models (concave and no concave) when they are working were studied. To make sure that the cylinder block is safe during the whole working process, it should satisfy the requirement of the allowable stress of material on the maximum load conditions. And the firing order of the cylinders are continuous. This paper focuses on the static strength analysis of the cylinder block and comparative analysis of the two structures.

Abstract: This paper estimates the static strength of a certain type of cooling fan designed by a company in the rotating speed of 1260 rpm and 1380 rpm, evaluates static strength according to the cooling fan’s permissible stress in F state and T1 state, estimates the fatigue strength according to the operation load of cooling fan suffering from different direction when locomotive running and evaluates the cooling fan fatigue life according to the IIW standard. Static strength and fatigue strength calculation using ANSYS companies in the United States commercial version of the ANSYS software to complete.

Abstract: The effect of the turbine installation position on two-phase flow of a single six-blade ruston turbine in stirred tank with different agitation speeds is numerically simulated by using the large eddy simulation combined with mixture model. The result shows that when stirring low-density mixture, with the increasing stirring axle speed, volume fraction of low-density granules near the paddle is higher, while that near the barrel is low. When the paddle is installed with close distance to the tank bottom, the upper low-density granules are transported to the tank bottom to form good stirring effect. With increasing of the paddle location, distribution of low-density granules is hardly found at the bottom of stirred tank.

Abstract: Fault diagnosis for wind turbine is an important task for reducing their maintenance cost. However, the non-stationary dynamic operating conditions of wind turbines pose a challenge to fault diagnosis for wind turbine. Fault diagnosis is essentially a kind of pattern recognition. In this paper, a novel fault diagnosis method based on enhanced supervised locally linear embedding is proposed for wind turbine. The approach first performs the recently proposed manifold learning algorithm locally linear embedding on the high-dimensional fault signal samples to learn the intrinsic embedded multiple manifold features corresponding to different fault modes. Enhanced supervised locally linear embedding not only can map them into a low-dimensional embedded space to achieve fault feature extraction, but also can deal with new fault samples. Finally fault classification is carried out in the embedded manifold space. The wind turbine gearbox ball bearing vibration fault signals are used to validate the proposed fault diagnosis method. The results indicate that the proposed approach obviously improves the fault classification performance and outperforms the other traditional approaches.

Abstract: Ball mills with double inlets and outlets (BMDIO) are widely equipped in milling systems of thermal power plants because of BMDIOs’ vantage on being able to pulverize various raw coal. In this paper, dynamic characteristics of mill’s coal level were studied by pulverizing coal mechanism analysis. Furthermore, models for filled level of mill were obtained with mathematical Equations. The nonlinear, strong coupling and large lag features of BMDIO’s dynamic characteristics were demonstrated by the model for level of materiel constructed in this paper. And, the model would be become the available theory basis for the calculation of pulverized coal into furnace and design of combustion in fossil-fired thermal unit.

Abstract: Emission characteristics of an electronic-controlled high pressure common-rail diesel engine with low-blend Gas-to-liquids (GTL) and low-blend biodiesel fuels are studied. Pure diesel fuel, G10 fuel (10% GTL blend with diesel fuel) and B10 fuel (10% biodiesel blend with diesel fuel) are used in this research. The results show that torque of the engine with pure diesel fuel is higher than G10 fuel, and B10 fuel is the lowest. Compared to the pure diesel fuel, the brake specific fuel consumption (BSFC) of the engine with G10 fuel decreases, but the B10 fuel increases slightly. Hydrocarbon (HC) emissions of the engine with G10 fuel or B10 fuel are lower than the pure diesel fuel, and the carbon monoxide (CO) emission increases slightly, and nitrogen oxides (NOx) emissions have no distinct change. Compared to the G10 fuel, the CO and HC emissions of the engine with B10 fuel are lower.

Abstract: In order to better research on the spray characteristics of biodiesel and n-butanol blends, an experimental study of spray characteristics of different fuel mixtures was investigated in a constant volume vessel using high speed photograph method, and analyzed the influence of different proportions of acidic oil biodiesel and n-butanol on the macroscopic parameters of spray penetration, spray cone angle and so on. The results show that with the increase of acidic oil biodiesel ratio, the air entrainment is weakened, spray penetration gradually increases and spray cone angle decreases under the same injection pressure and back pressure. After adding n-butanol in acidic oil biodiesel and diesel mixture fuel, the surrounding air entrainment is enhanced, and spray front end widen. With the increase of mixing ratio, spray penetration increases first, then decreases. The spray cone angle increases after adding n-butanol, and decreases with the increase of mixing ratio. The results show that adding n-butanol can be used as one of the methods to improve biodiesel spray characteristics.

Abstract: The changing of injector nozzle structure will influence the combustion and emission properties in diesel engine. Three-dimensional numerical simulation of multiphase flow of mini-sac nozzles of high pressure common rail were calculated by using the computational fluid dynamics ( CFD ) method in this paper. The results shown that this method can be more accurately obtained a lot of useful information on the flow field inside the nozzle in a relatively short period of time, and it is convenient for analysis and research the influence of geometry parameters on the flow characteristics inside the nozzle. The paper also studied the influence of nozzle inlet pressure, the angle between the axis of the hole and the axis of the injector and nozzle entrance radius to the flow characteristics inside the nozzle. It also studied the distribution of internal pressure, velocity of flow, gas-phase volume fraction and turbulent kinetic energy. These studies provided a favorable basis for the design and improvement of the nozzle structure and optimize combustion system matches.

Abstract: To increase the prediction speed of ice accretion on the 3D engine inlet, the Proper Orthogonal Decomposition (POD) method was introduced. Taking the ice shapes from CFD numerical calculation results as samples, in view of the change of icing temperature, the procedures of predicting the ice shapes by POD method were introduced, which used ice shapes’ coordinates and ice accretion height as compute parameters, respectively. The POD and CFD ice shapes were found coincident, which indicates that the POD method can fast and accurately calculate the 3D engine inlet ice shapes. The results from the two different POD parameters were shown and compared, and the ice shapes were nearly the same, which means they have the same effect. However, the POD method based on ice accretion height is simpler and more appropriate

Abstract: With the promotion of energy-saving and exhaust reduction policy, the application of diesel engine has been further extended. The formation and harm of nitrogen oxides (NO_X) and particulate matter (PM) were mentioned in detail, which are major pollutants in diesel exhaust. Reviewed the research progress and application of diesel engine exhaust emission control technology, fuel quality improvement, internal purification and after-treatment are introduced separately. Finally, the future development direction of exhaust emission control technology was given combining research situation of diesel engine.