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51.
52.
Lin Ge Luo Xiaonan Li Chunjing Shi XiquanLi Yi Wang Ruomei 《Applied mathematics and computation》2011,218(2):492-501
The balance theory of 3D garment simulation tries to integrally study the complex system of human body-fabric-environment. The theory includes the geometrical balance, dynamic balance, pressure balance, and heat and moisture transfer balance. In this paper, the ICAD-balance equations are established based on the framework of balance theory and the heat and moisture transfer model of garment. A finite volume method is employed to solve the equations. Experiment results show that ICAD-balance equations can excellently simulate real situation. Therefore, our balance theory provides a good tool for customized clothing design, electronic mirror for clothing-test-platform, and comfortable clothing evaluation research. 相似文献
53.
防护林带:湍流的数学模型与计算机模拟 总被引:3,自引:0,他引:3
虽然防护林用于减小风速、控制热量和水汽传递及污染物扩散、
改善气候与环境、增加作物产量等已经有几百年了, 但直到近几十年,
人们才开始系统地研究防护林空气动力学的遮蔽机制.在本综述中,我
们考察了绕防护林带的流动与湍流控制机制,最新的模型与数值模拟
研究情况;通过数值模拟与实验数据的比较,来了解防护林带结构与防
风效果之间的关系;讨论数值分析如何及为什么能够得到所需要的结果.
本文将从多孔隙防护林带流动基本方程组的推导开始,讨论数值模型及
模拟过程,对附体与分离流动进行预测;分析了遮蔽机制与动量交换;对
风向、防护林密度、宽度和三维性对流动与湍流的影响作了系统的论
述.还对热流和土壤水分蒸发的新模型及数值模拟作了简述.最后,我们
对网络工作站、群和高性能分布式并行计算机及其对防护林带模型预
报能力的提高作了讨论. 相似文献
54.
55.
船用气水分离器惯性级流场分析及阻力特性研究 总被引:4,自引:0,他引:4
采用二阶全展开ETG有限元与大涡模拟(LES)相结合的算法,对120-20-35-3型船用气水分离器惯性级在不同雷诺数条下的流动进行了模拟,通过其中一组雷诺数条件下计算所得该实验件阻力系数与物理实验所得阻力系数相比较,确定出该雷诺数条件下采用大涡模拟时所需的亚格子应力模型常数,将该常数带入其它各组雷诺数条件下的计算中,并将计算结果与相同条件下的物理实验结果相比较,证实了该常数的通用性。该常数一经确定,对各雷诺数条件下的流场进行分析,结果反映出采用二阶全展开ETG有限元与大涡模拟(LES)相结合的算法可以捕捉到非常丰富的涡系及涡动的时变过程。在流场分析的基础上本文计算了该实验件内的能耗场,计算结果表明实验件内的能耗主要集中在大涡丰富的区段内。 相似文献
56.
The influence of macro-scale heterogeneities on the imbibition process is investigated for Savonnières, a French layered limestone. Free uptake experiments are performed both parallel and perpendicular to the bedding. It is found that the position of the different layers, and the exact material properties inside each layer can significantly influence the imbibition process. The experimental results are compared with numerical simulations. For the flow simulations, moisture permeability of the different layers is obtained with the upscaling technique presented in Part 1. Good agreement between simulations and experiments validate the proposed upscaling from meso to macroscopic scale. 相似文献
57.
Hydraulics of Peat Filters Treating Septic Tank Effluent 总被引:3,自引:0,他引:3
Peat is an alternative filter medium for the treatment of various waste streams including septic tank effluent. The water holding capacity and adsorption capacity of peat make it a favorable filter medium over sand or gravel which are commonly used as the filter medium for the drainage field of septic systems. This paper presents the results of a field study to evaluate the hydraulics of a peat filter used to treat the septic tank effluent from a public school west of Ottawa, Canada. An experimental box was placed within the filter during its construction to provide access to the vertical profile of the peat layer. The filter is periodically pulsed with septic tank effluent, which is distributed over the top of the filter and flows vertically through the peat. The filter was instrumented with tensiometers and transducers to monitor the pore water pressures in response to a pulse of septic tank effluent. An in-depth study of the hydraulics of the system was completed. The soil moisture retention curve and the hydraulic conductivity as a function of density were determined in laboratory experiments. A one-dimensional unsaturated flow model was used to predict the pressure response due to a pulse. A comparison of the field and model results illustrates the impact of the density variations, and the corresponding hydraulic conductivity variations, on the model predictions. The compaction of the peat is an important design consideration for the filter since it directly impacts the flow characteristics and the hydraulic retention time within the filter. 相似文献
58.
A. Naceri 《Mechanics of Composite Materials》2009,45(3):331-336
The properties of moisture diffusion parameters and their effect on the tensile mechanical behavior of a fabric composite
(glass fiber/epoxy resin) in the warp and weft directions were investigated. The water up take by specimens conditioned in
a humid environment under different relative humidities (0, 60, and 96% RH) at a constant temperature of 60°C was evaluated
by weight gain measurements. The water absorption followed Fick’s diffusion law in the fabric composite. A comparison between
the values obtained for the moisture diffusion coefficient and the equilibrium moisture content at the laboratory and those
given by Loos and Springer showed that the parameters depended not only on the nature of materials, but also on environmental
conditions. The effect of moisture absorption on tensile characteristics of the composite, which was tested in uniaxial tension
in the warp and weft directions at constant imposed displacement rates up to failure, showed a significant reduction in the
ultimate tensile strength of the specimens conditioned at 96% RH.
Russian translation in Mekhanika Kompozitnykh Materialov, Vol. 45, No. 43, pp. 479-488, May-June, 2009. 相似文献
59.
Faitel'son E. A. Korkhov V. P. Aniskevich A. N. Starkova O. A. 《Mechanics of Composite Materials》2004,40(1):57-66
The results of a complex study of structural changes in a cured Norpol 440 polyester resin under the action of damp environment and mechanical loading are presented. A considerable effect of absorbed moisture on the structure and some characteristics of the material is revealed by using thermophysical methods and X-ray diffractometry. The joint effect of moisture and mechanical stress is estimated by investigating the creep in stationary and nonstationary moisture conditions. The anisotropy of the material structure formed during creep is evaluated from the results of dilatometric measurements. It is found that the degree of anisotropy of the material after creep accompanied by moisture sorption is higher than that after creep in the conditions of moisture equilibrium with atmosphere. It is established that the aftercure and relaxation of the residual creep deformation come to an end at heating to 80-85°C. At a further rise in temperature and repeated heating, changes in the material structure are not observed. 相似文献
60.