Numerical simulation of remodeling in mandible under orthopedic loads

The research on the remodeling in mandible under the action of orthopedic loads is important for the determination of orthopedic scheme. a three-dimensional finite element model of mandible and temporomandibular joint is established. Using Cowin Remodeling Law, the finite element simulation of the remodeling in mandible during the orthopedics under the action of orthopedic loads is carried out. Comparing the numerical results after remodeling with those before remodeling, it is demonstrated that the normal remodeling greatly affects the distribution of strain and strain gradient on the surface, therefore the effect cannot be ignored in the determination of the orthopedic scheme.     

Simulation of methanol steam reforming in micro channel with lattice Boltzmann method

Lattice Boltzmann method is used to simulate the methanol steam reforming process in a micro channel. Lattice evolution model with dual rate kinetic parallel reaction mechanism is established. The impacts of boundary temperature, inlet velocity on reaction outlet parameters, such as methanol conversion rate, outlet concentrations of hydrogen and carbon monoxide and maximum temperature difference, are studied. It is found that under a certain boundary temperature and inlet velocity, when the methanol molar ratio, boundary temperature and inlet velocity are 1.3, 523 K and 0.1 m/s respectively, the methanol conversion ratio can reach the highest value of 94.36%, together with the concentrations of hydrogen and carbon monoxide of 0.098 9 and 0.009 5% respectively. With the increase of boundary temperature and decrease of inlet velocity, the concentration of CO will increase.     

Numerical Simulation of Flow field and Temperature field in Combustion Chamber Widened Suddenly

The flowfield and temperature field are numerically Simulated by the mathematical model of the fluid flow and heat transfer in circular combustion chamber widened suddenly. The distributions and influence factors of the flow field and temperature field are studied in it. The results have the guiding significance for the design of combustion chamber. The mathematical models can serve as the quantitative analysis methods for design.     

Numerical simulation of backward flow of methane roof layer in an airway

We study methane backward flow in the laneways at various wind velocities and angles based on computational fluid dynamics theory; analyze the backward flow area length, the concentration distribution and the methane roof layer thickness. The results show that the methane roof layer would move against the airflow in a declensional ventilated airway if the downward air velocity is not large enough. The faster the airflow speed, the smaller the methane backward flow area becomes, and the methane roof layer becomes thicker and shorter. In a declensional ventilated airway, the methane/air mixing capacity increases with the increase of the inclination of the airway, and the thickness of methane roof layer decreases with the increase of the inclination of the airway.     

Numerical simulation of outburst prevention air door destruction by coal and gas outbursts

We explore the destruction of outburst prevention air doors by coal and gas outbursts using numerical simulation. The reflective overpressure when an outburst acts on doors is elucidated, and its formula is obtained. The destruction of outburst prevention wind doors by coal and gas outburst are simulated using ANSYS software based on data of wind door pressure obtained by similarity simulation experiment. The simulation results show that the weakest place of gate posts is where the wind tube is. Simulation results also show the first shock wave pressure that acts on an outburst prevention wind door is not the maximum one. Due to the effect of reflected overpressure, the outburst prevention wind door pressure will reach the maximum in several milliseconds. This finding is similar to the experiment result.     

Numerical simulation on natural convection of water near the maximum density in horizontal annulus

In order to understand the basic characteristics of the heat transfer of natural convection of water near the maximum density in a horizontal annulus, two dimensional numerical simulation was conducted using the finite volume method. The outer wall temperature was maintained at 0 ℃, and the temperature of inner wall at 1 ℃ to 10 ℃. The results show that the heat transfer coefficient at the inner wall first decreases with increased annulus width, then increases, and then constantly decreases with the increased inner radius in the region of calculation. When the temperature difference is below 4 ℃, the heat transfer coefficient increases with increasing temperature difference. When the temperature difference exceeds 4 ℃, it decreases with the increase of the temperature difference. Finally, the formula of heat transfer at the inner wall was obtained by using stepwise linear regression.     

Numerical Simulation in Flow Field of CNG Vehicle Catalytic Converters

The steady flow in the catalytic converters of CNG was simulated. The gas can breakaway in the entering pipe and the flow of the gas can convergence well in the exhaust pipe. The flow distributing mainly depends on the flow capability of the expanding pipe. The pressure falls apparently in the carrier of catalytic converters. The noble metals in the center of the catalytic converters are consumed more quickly than the edge zone.     

Numerical Model of Tuyere Pulverized Coal and Raceway Coke Combustion in BF

Based on inevitability analysis of Tuyere coal and Raceway coke combustion numerical simulation, this paper retrospects previous study and summarizes two phase turbulent flow numerical model of pulverized coal and air, pyrogenation and radiation transmit-heat numerical model of pulverized coal volatile ash, combustion energy equation of coke grain. The authors put forward a new idea of boundary condition using CCD technique.     

Numerical Simulation of HVAC in Vehicle Air Conditioning System

Through applying the theory of Computational Fluid Dynamics(CFD),this paper describes the numerical simulation of a typical HVAC in vehicle air conditioning system for improving on the structure of HVAC,shortening the time periods of product design and reducing the costs of design. By applying CFD to simulate designs and improve on the inconsepuential designs,it can make the symmetrical distributing of velocity and temperature of air in HVAC,obtain a proper value of velocity and reduce the yawp value.From the result of simulation,the numerical model has been optimized.It advances the capability of air-conditioning system.While applying CFD to the design of HVAC,it carry the purpose of shortening design the periods of HVAC and reducing the costs of empolderings and tests.     

Numerical Simulation of Catalytic Combustion of Extremely Low Concentration CH4

This paper used FLUENT to simulate the Catalytic combustion characteristics of extremely low concentration methane in microchannel of honeycomb combustor which was coated with catalyst Pt/Al2O3.It analyzed the effect of inlet CH4 concentration, temperature of catalyst wall and inlet fuel velocity on CH4 conversion ratio. The results show that CH4 conversion rate is increases with the increase of inlet CH4 concentration and catalyst wall temperature and the decrease of inlet fuel velocity. When inlet fuel velocity is 0.1 m/s, CH4 volume concentration is 1%, catalyst wall temperature is 950 K, the conversion ratio of CH4 can achieve to 97.0%.     

Numerical Simulation of Strata Movement Behavior in Deep Excavation

According to the complex conditions of deep excavation in Nantong mine, FLAC program are carried out for strata movement, ground pressure and surface displacement due to coal extraction. Based on the analysis of Nantong mine, the basic features of strata movement, the fundamental behavior of ground pressure and the related parameters of surface displacement are obtained. The results are of referential value for mining, supporting and preventing of surface displacement.     

Numerical Simulation of Fluid Flow in Converter Combined Blown Bath

The fluid flow mathematic models in converter combined blown are set up.It is simulated for flow state and velocity distribution of gas and stir action in different behaviours of bottom blown,top blown and combined blown by software PHOENICS(Parabolic Hyperbolic or Elliptic Numerical Integration Codes Series).In normal operation condition of ejection guns,the fluid flow in bath is axisymmetric three-dimensions flow.The results reveal out dynamic main area and slowness cyclone zones,also asked dead zone abating or erasing in practice.These shows that bottom blown gun ought to 0.5~0.7 circumference diameter of fused bath using top-bottom combined blown process.     

Numerical simulation and on-site test of anincreasing pipe gas delivery capacity device

The theoretical analysis and experiment show that the wall oscillation can reduce the friction drag of the pipe. The operation mechanism, on-site test and numerical simulation of the Increasing Gas Delivery Capacity Device for the Pipe (IGDCDP) invented by the author are introduced in the paper. The on-site test shows that the IGDCDP can not only reduce the friction drag, but also enhance the gas delivery capacity obviously in the natural gas network. The numerical simulation results show that at the time of inducing some new vortex disturbance waves, the pressure pulse wave generated from the impinging edge has an effect on the oscillation cavity wall to cause oscillation with the large structured vortex rings, so the oscillation cavity is the main component that generating the pulsed jet.     

Numerical Simulation of the Flow Resistance in TWC with Guiding Components

The steady flow resistance in the Three Catalytic Converters(TWC) with guide components of CNG(Compressed Natural Gas)cars is simulated.The location set guide flow equipment has great impact on pressure losing which can be adjusted to the optimal while adopting some measures.Pressure losing by adding combination flow-guide plate which can evidently improve flow field uniformity has a little impact on engine.Pressure losing will be small while adopting optimal location and guiding-flow construction.     

Simulation of Ventilation and Air Conditioning Project in Xiluodu Underground Hydroelectric Power Station

For the benefit of environment protection and sustainable economic development especially in western china, to build more hydroelectric power stations is a basic policy of our government. Xiluodu project is the biggest underground hydroelectric power station. which includes 18 power generation units with a capacity more than 12 600 MW. By establish a set of heat and humidity balance equations applying on the Xiluodu project underground workshop with its boundary conditions, this paper has present an one_dimensional heat conduction model to simulate its dynamical heat transfer process. On the purpose of compare deferent design schemes of HVAC system, a package of software for numerical simulation is developed. In this paper,we have also recommend some criteria for the evaluation of HVAC system design schemes. The computation result has show that if utilizing the reservoir water and AC chiller to process the air,combing other anti_humidification technical measures,it will assure the anticipated air quality of underground facilities.     

A Numerical Simulation of Two-Dimension PoissonProcess and its Application in Simulation of an Uneven Road

An attempt is made to develop a numerical simulation rnodel of two-dimensionpoisson prcoess. Simulated and checked on computer,the road surface and spectrum of the roadwhich close to the ISO,The methed developed in this pa per is proved to be feasible and practicable.     

Numerical Simulation on Confluence of the Two Rivers in Chongqing City

Flows of the confluence of Yangtze River and Jialing River in the city of Chongqing are numerically simulated by using Delft3D Model with staggered grids and ADI integral method. The water level, flow velocity and drogue trace are studied. Comparing the numerical results with observed data shows good agreement. Therefore the computational model and the simplified parameters are of good accuracy and have practical meaning. The results show that the contamination will linger near the Caiyuanba area and drift to Chaotianmen and the right bank of Yangtze River upstream. The results can be used to forecast flood, inspect contamination and management of riverway in the city.     

Numerical simulation of NO and N2O emission in fluidized bed reactor

Both NO and N2O emission in fluidized bed reactor are studied by numerical simulation. The effects of excess air ratio, coal composition and co combustion of coal and biomass are researched. The results show that NO and N2O are the main products of the NOx in the fluidized bed reactor combustion, and the emission of NO and N2O increases with the excess air ratio increasing. The NOx production has strong relationship with coal composition. The nitrogen content of the coal plays an important role in the production of NO and N2O, as well as oxygen to nitrogen mass ratio and hydrogen to nitrogen mass ratio. In the co combustion process of coal and biomass, carboxyl group have remarkable effect on HCN production, which reduces the content of NO and NO2. The co combustion of coal and biomass can reduce the emission of NO and N2O.     

Numerical Simulation of Laminar Mixed Convection Heat Transfer in Vertical Narrow Rrectangular Channels

Using N-S function, and transforming the gravity item to temperature and differential pressure related items, the authors simulate the mixed convection heat transfer in vertical narrow rectangular channels. The results reveal that intense chimney effect exists in cross-section of the whole field and nearby the wall of the channel, When flow is laminar, the velocity of main flow will be decreased, disturbing nearby the heating wall is strengthened, and the convection heat transfer of vertical narrow rectangular channel is enhanced. It also can destroy the uniformity of the heat transfer coefficient distribution. Considering the reliability of equipment, this kind of convection pattern only can be used in low heat flux. The buoyancy-influencing model putted forward can predict mixed convection heat transfer, and also can be used to simulate the turbulent mixed-convection heat transfer problem.