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In this paper, the 3D flow analysis model of gasoline engine turbocharger compressor was built by using the software NUMECA. The flow fields of the vaneless diffuser and volute, such as airflow velocity field, temperature field, pressure field and the entropy field were simulated. The internal flow performance of the vaneless diffuser and volute were analyzed. The simulation results show that the field changes accord with the compressor characteristics, thus the vaneless diffuser and volute of the compressor design is reasonable. The approach of numerical simulation and flow field analysis by using CFD method can accurately predict the compressor performance. The research methods and conclusions provide theoretical and practical reference for the optimization design of the compressor.

Non-autoclaved and non-sintered fly-ash perforated brick is a kind of new material for non-load-bearing walls. In order to promote the application of this new material in village and town buildings of seismic area, compression and shear strength of non-autoclaved and non-sintered fly-ash perforated brick masonry was tested and crack and failure progress was analyzed. The test results show that the failure processes and characteristics of the non-autoclaved and non-sintered fly-ash perforated brick masonry in compression and in shear are similar to that of the common brick masonry, however the non-autoclaved and non-sintered fly-ash perforated brick masonry tend to fail in brittle manner. The compression and shear strength are all less than that of the common brick masonry. A mathematic model of 6 degrees polynomial was used to express the compressive constitutive relationship and the whole process of non-autoclaved and non-sintered fly-ash perforated brick masonry in compression was described. The curve was close to the measured data.

Let π be a set of primes. Isaacs established the π-theory of characters, which generalizes the theory of Brauer module characters. Based on Isaacss work, we introduce the definition of Mπ-groups, and prove that if G=NwrCp is an Mπ-group, where Cp is a cyclic group of order p and pπ, then N is an Mπ-group.

A geometric model and finite element grid model of JQ40A gasoline engine turbocharger were set up based on the CFD software NUMECA. And the stress, deformation and vibration modal analysis on turbocharger’s compressor impeller, turbine and integrated turbine box was carried out by software ANSYS. The result shows that thin blade impeller design, weight reduction design of the turbine is beneficial to reducing the maximum structural stress, deformation and rotation frequency. The integrated design of the exhaust manifold and the turbine housing is helpful to reducing the flow resistance and the vibration frequency, so as to effectively avoid the resonance region, ensure turbocharger’s reliability and make for enhancing aerodynamic performance. Research methods and conclusions which are of important theoretical significance and practical value, provide basis for optimization design of turbocharger.

In this paper, the finite element model and mesh model of JQ40A gasoline engine turbocharger compressor was built by using Computational Fluid Dynamics(CFD) software NUMECA. The compression ratio and efficiency characteristics of compressor were simulated and verified experimentally. Based on the established models, the airflow velocity field, pressure field, temperature field and entropy field in the compressor volute passage and impeller clearance were simulated and analyzed. The simulation results show that the pressure loss is low and the flow passage design is reasonable; A rational volute export curvatureRdoes not affect the compressor efficiency; the compressor impeller rim size can be adjusted to accommodate the engine torque characteristics; the engine speed affects internal loss of the flow field; within a certain range the impeller tip clearance is smaller, the higher the efficiency of the compressor is. The research methods and conclusions provide a basis for the optimization design of the compressor.

Reactive powder concrete (RPC) is an ultra-high performance concrete (UHPC). Cement and silica fume content of RPC are generally rather high compared to the conventional concrete. The aim of this paper is to decrease the cement content of RPC by using phosphorous slag powder. Firstly the effect of grinding time on the activity index of phosphorous slag was investigated. And then, the mix proportion design of this UHPC containing phosphorous slag powder and silica fume was done through orthogonal design. The results indicate that the utilization of phosphorous slag powder in RPC is feasible when the dosage of phosphorous slag powder is about 35% (by weight of the binder) and the water-binder ratio is less than 0.18. By substituting phosphorous slag powder for a part of cement and keeping the water-binder ratio at about 0.14, UHPC specimens whose content of mineral admixtures, including phosphorous slag powder and silica fume, was about 40%~50% (by weight of the binder) were obtained after they had been cured in 80 °C water for 72 hours. The compressive and flexural strength of those specimens was more than 150 MPa and 20 MPa respectively.

This article has established a three-way catalytic converter reactor model of gas phase reactions and surface reactions. Based on this model, cold start transient emission numerical simulation has been done. The result shows that the influence of ambient temperature and exhaust temperature on the HC is much greater than the impact on the CO.

In the paper, the natural gas engine (NGE)model based on AVL BOOST software is built and simulated. The simulation value and experiment value coincide, showing that the NGE model is correct and reasonable. On this basis, the model has been used to analyze the effect of the key parameters, such as compression ratio, ignition advance angle, valve timing, supercharging ratio on the engine power, maximum combustion pressure, exhaust temperature, the maximum rise rate of pressure. Combined with the relevant theories of engine, the value ranges of the key parameters can be designed. The research achievement is valuable in the development and optimization matching of the NGE.

In order to reduce effectively the particulate ignition temperature of Diesel Particulate Filter containing MnOx-CeO2 catalysts，the physical and mathematical calculation models of MnOx-CeO2 catalysts were established on Diesel Particulate Filter，and according to bench tests, the activity measurements of the five different concentrations were processed for MnOx-CeO2 catalyst. The results indicated that when concentration is 20ppm, the ignition temperature can be droped about 105°C, activity measurements of Kp、Kpm and ΔKp decrease 10%, 8% and 7% respectively. Meanwhile, regeneration time can be shortened to 7min. It shows that Diesel Particulate Filter which contains concentration of this type not only has higher regeneration rate and level , but also decrease effectively exhaust back pressure.

In order to further reduce sensitivity to misalignments not only double crowned pinion but also profile and longitudinal geometry modified face gear have been studied. The profile geometry modification were realized by application of rack cutters, and applied parabolic motion of the center of grinding disk for the pinion and face gear longitudinal crowning. Tooth contact analysis (TAC) and Load Tooth contact analysis (LTCA) have been performed to simulate the meshing and contact of double-crowned face gear driver. The further avoidance of edge contact in presence of big magnitude misalignment was illustrated with numerical examples.