首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
The time-changing analysis model for concrete filled steel tubes was established based on the time-changing concrete model of CEB-FIP MC90, in which the interaction between steel tube and concrete core was considered by the restraint conditions of master and slave nodes. The numerical simulation method was developed for analyzing the whole construction process of high-rise CFST structures. A real structure was taken as numerical example, in which the influence of concrete creep and shrinkage as well as construction process was considered. The results of numerical simulation are compared with those obtained from on-site monitoring. It is shown that the concrete creep and shrinkage as well as construction process have big influence on high-rise CFST structures, which should be taken into account in designs and constructions.  相似文献   

2.
With societal development, wastes exist in industry, agriculture and human life. In particular, a large volume of urban industrial sewage is discharged and pesticides and fertilizers are widely used, leading to groundwater pollution in many areas. Based on a water quality model of hydrodynamic dispersion and the multi element balance (MEB) method, a general program for simulating groundwater flow and quality is carried out using the program VC++ for visual presentation. Using this program in a case study, the transportation mechanism of groundwater flow and quality is simulated numerically. The result indicates that the program is visual and can be manipulated well. It offers a point of reference for the reasonable exploitation, protection and utilization of the groundwater.  相似文献   

3.
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.  相似文献   

4.
Combined microwave-convection drying characteristics are investigated by numerical simulation. Combined microwave-convection drying has advantage of swift drying and sterilization. Based on qualitative analyses on the mechanism of combined microwave-convection drying, the differential equations are established and the numerical simulation method is described. The humidity, vapor pressure and temperature, along the radius in a spherical pill, are calculated by the numerical simulation during drying process. The calculation results show the relationship between humidity, vapor pressure, temperature and drying time, and that drying process is greatly influenced by input microwave power. The calculation results are good consistent with the experimental datum.  相似文献   

5.
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.  相似文献   

6.
7.
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.  相似文献   

8.
沿海防护林网防风效应数值模拟研究   总被引:1,自引:0,他引:1  
为研究沿海防护林网的防风效能,采用计算流体力学软件FLUENT对上海浦东新区的水杉林网周围的气流场分布进行了数值模拟。结果表明:水杉林网对气流有着明显的削弱作用,风速在林带前5 H左右处逐渐下降,在林带后出现回流现象,随后林带对气流的作用逐渐减弱,风速逐渐恢复。各林带的有效防护距离在10 H左右,因此,林网中林带间距设置在15 H左右比较合适。  相似文献   

9.
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.  相似文献   

10.
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.  相似文献   

11.
This paper provides a theoretic basis to analyze the mechanism of control rod dropping and a solution method to solve the process of dropping. The authors analyze the effect of different forces acting on the control rod in detail. A mathematical model is built and a program is written to solve the process of downward motion. Finally, the model and relative coefficients of the model are modified according to the experimental data. The modified model can well simulate the process of dropping of the control rod, which gives a powerful proof to the accuracy of the model.  相似文献   

12.
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.  相似文献   

13.
With numerical simulation, an analysis is done on the three-dimension air flow in the helix intake port of a diesel engine. The anthors acquire the distribution of characteristic parameters of air in the port, such as velocity, pressure, turbulence kinetic energy, as well as the flow coefficient and rotate moment around the erect axes at the outlet. The results of simulation indicate that the negotiability of the port is very good while the ability of forming eddy can be enhanced, so several improve measures have been put forward. Comparing with simulation results of these measures, it finds out that the method of combining increase the distance between the definition curve of volute cavity and central line of valve protruding support as well as increase the eddy shell angle can obviously enhance the ability of forming eddy, which is an efficient and rational method.  相似文献   

14.
15.
The article uses the large Eddy simulation of Fire Dynamics Simulator(FDS)and parallel computing methods to numerical simulation on fire facilities in an underground garage. The main research is the effects of exhaust system and automatic sprinkler system in fire scene. Results show that: exhaust system can discharge high temperature and toxic gases, reduce smoke concentration and improve visibility effectively. Automatic water spray equipment mainly reduces heat release rate, and make smoke flow near the ceiling, which control the fire temperature very well. Combined with mechanical smoke exhaust system, it can better control the development of fire and effectively put out the initial fire. This study provides reference for fire safety design and assessment, which is of great significance to reduce casualties and property losses caused by the fire of underground garage.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
In this paper,a numerical simulation of the casting process for making the MMC.using the PEM, is studied.The convection of liquid metal and the release of latent heat of solidification are taken into account.The algorithm and program for axisymmetric casting model are developed to the problem of coupling between flow and heat transfer,as well as phase change.The variational curves of temperature,the position of flow front and the distrsbutions of volume fraction of solid metal in matrix and their variation with time are obtained.The influences of technological paarmeters to casting are discussed.  相似文献   

19.
提高烤房内温度及气流组织分布的均匀性,不仅可有效提高烟叶烘烤质量,而且可在一定程度上缩短烘烤时间,从而降低烘烤能耗。以密集型标准烤房为模拟研究对象,建立了装烟室内空气流动的k-ε两方程三维紊流模型。利用大型计算流体力学软件Fluent,对密集烤房内温度场及速度场进行了系统地数值模拟。分析了装烟室内温度及气流分布的均匀性,并获得了密集烤房合理的送风量。相关的数值模拟结果可为密集烤房结构、气流组织分布优化及循环风机选型提供参考。  相似文献   

20.
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.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号