Numerical Simulation of Frost Characteristic on Refrigeration System Evaporator

In order to analyze the running performance of refrigeration air conditioning system and confirm thaw periods in reason, frost process and change process of frost thickness of evaporator surface are studied. Based on basic theory and experiential formula of heat transfer process and mass transfer process, the math model of mass transfer of vapor on evaporator outside and growth process of frost are established. Aiming at a sort of finned-tube evaporator, frost process and change process of frost thickness are simulated numerically. The influence of environment parameters is analyzed.     

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.     

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.     

地方特色食品辐照保质技术研究

经济的快速发展,对地方特色食品工业提出了更高的要求。通过食品辐照保质技术的研究,解决地方特色食品加工过程中贮存保质的难题,从而为地方经济建设服务。     

Numerical Analysis of Diffusion Characteristic in the Proton Exchange Membrane Fuel Cell

A two-dimension,steady-state,multi-component transport model is presented to investigate the cathode performance of a proton exchange membrane fuel cell with an interdigitated gas distributor.Darcy law is used to describe the flow in the porous media.Subsequently,the model is applied to predict the pressure,velocity and mass fraction distributions in the electrode and explore the effect of the change of differential pressure between the inlet and the outlet,electrode thickness and rib width on the performance of fuel cell.The results show that: current density creases with the higher differential pressure between the inlet and outlet,but the increment is diminishing;electrode thickness has an optimum value which depends on the electrode morphology and the gas distributor design parameters;using narrower electrode rib can improve the performance of fuel cell.     

Numerical Simulation of the Solidification Process Under the Effect of Nature Convection

The process of solidification is numerically simulated with control volume method. The authors study the nature convection in the liquid phase and flow pattern of nature convection during the process of solidification. The result of simulation shows that there are the global flow cells inside the liquid phase, and the local circumfluence exists in the global cells. Especially, the authors analyze transformation of the interface between phases under the effect of free convection on the process of solidification.     

Simulation on the Characteristics of Flow Pattern in Sprial uP-flow Reactor

In order to analyze the reason why the Spiral Up-flow Reactor system has excellent removal effect of COD, N and P, the authors use PHOENICS, a computational fluid dynamics program, to investigate the hydraulic characteristics and flow model of the anaerobic part of Spiral uP-flow reactor. The result shows that the fluid in the reactor unit flowed upward by the spiral way, and that flow pattern was combined by plug flow and complete-mix flow, and that the percentage of plug flow was about sixty-five percent. Spiral Up-flow Reactor units the Characteristics of PFR and CSTR, which makes it work well.     

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.     

1961—2010天水市光、温、水资源变化特征及其与粮食产量的关系

为了探索气象资源变化与粮食产量的关系,运用天水市7个国家基本（一般）气象站1961—2010年日照时数、温度、降水资料,借助于气候变化率、Mann-kendall、Z-score标准化等方法,对该地近50年农业气候资源变化规律进行分析,并建立了综合资源指数模式。结果表明：1961—2010年,该地日照时数以30 h/10 a气候变率下降;年平均气温以为0.40℃/10 a气候变率上升,年平均最高气温以0.36℃/10 a气候变率上升,年平均最低气温以0.39℃/10 a气候变率上升;降水量以20 mm/10 a的气候变率下降。综合资源指数呈二次曲线变化,变化的转折点在1982年;1961—1982年以0.08/10 a气候变率下降,1982—2010年以0.48/10 a气候变率上升。与当地的实际粮食产量变化基本吻合。     

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.     

Simulation of Evacuating Buffer in High-rise Building Fires

Buffer zone set between aisle and anteroom is proposed to improve the traditional mode of pressurizes mechanic smoke extraction. Fire Dynamic Simulation is used to simulate the model of high-rise fire. Eight models are set and analyzed, in which the smoke temperature distribution and concentration distribution are compared, and the best parameters is worked out. The result shows, when exhaust smoke volume is constant, the velocity of air curtain is as low as possible; when the volume of air curtain is constant, the smoke volume is as low as better. Based on the comparison, it is found that the smoke removal efficiency of mode 4 is the best one, which is about 74.06%. The evacuating buffer not only can let smoke out timely, but also can guarantee safe personnel evacuation.     

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 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 Berthing Velocity of the Ship

Based on the field data of berthing velocity for the ship (10000t-50000t), the berthing velocities have been numerically simulated by using Monte Carlo method in this paper. After statistical tests, it shows that the maximum values of the berthing velocity follow a Gumber distribution and the probability curves of failure for the means of maximum values are also obtained. The present results have been compared with the ones determined by specification of harbor engineering both at home and abroad.     

刺葡萄的品质分析及加工性能研究

选取湖南省几个有代表性产地所生产的刺葡萄进行了品质分析,对其加工特性进行了讨论。结果表明,刺葡萄主要成分的平均含量为:总糖13.21%,总酸0.35%,糖酸比37.8,抗坏血酸21.92m g/100g,单宁0.04%,蛋白质0.88%,果胶0.81%和纤维素0.23%。从加工性能分析,刺葡萄是制造果汁的优良原料。     

一次黄渤海海上大风过程模拟分析

2009 年2 月13 日黄渤海海域冷锋过境,出现海上大风天气过程。为分析此次大风过程的形成机理以及物理量场的分布特征,利用WRF数值模式对此次大风过程进行数值模拟。研究发现,WRF数值模式对这次冷锋型天气过程的高、中、低空天气系统的演变和强度模拟效果较好,成功揭示了黄渤海沿海地区大气环流形势及控制天气系统演变的主要特征：此次大风过程主要是冷锋过境引起的大风降温过程,冷空气开始入侵,地面气压梯度力增强,风速开始增大,同时明显反映出冷暖气团的斜压性,锋面的斜压性增强地面风速。物理量场的模拟说明,当测站上空由上升运动转为下沉运动时,风速逐渐增大,风速的大小与下沉运动的强度呈正比。温度和相对湿度场的分布反映了锋面过境的系统演变。     

Analysis and FEM Simulation of the Forming Process of Front Bumper Bracket

The processing characteristics of the front bumper bracket are analyzed,and a reasonable process scheme is worked out.The three-dimensional sheet metal forming analysis software PAM-STAMP are adopted to simulate the bracket's drawing process.Then the surface of die is proved fine through analyzing the FLD diagrams and the forming results.An economical and optimized die structure is decided,and a complete set of dies of the bracket is designed.The spacing block is added in the sizing mold,which control the size precision of end products and assembling columns actively,and finally the certified products.The material utility and the labor productivity are raised,the production cost is saved,and the mold design quality and the efficiency are improved effectively.     

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.