内燃机工作过程模拟分析与研究

采用FIRE软件进行了内燃机工作过程的数值模拟分析,得到与排气噪声影响因素有关的燃烧气体的温度、压力参数,同时还得到了在这些工况下NOx的排放情况,为发动机的燃烧、排放以及燃烧室的优化设计等的研究提供了基础,同时还为进一步设计发动机消声器提供了信息。     

ROTAX914缸内直喷式发动机分层混合气形成的模拟研究

按照直喷式汽油机的要求对ROTAX914汽油机的部分结构和参数进行了改造和调整,并使用AVLFIRE软件对改造后缸内混合气的形成过程进行了模拟研究。研究发现,喷射角度、喷油定时、初始滚流比浓区中心位置、浓区中心的形成、浓区中心的形状及位置有较明显的影响;通过喷射参数的调整及缸内气流的组织,在燃烧室中形成了满足直喷式发动机要求的分层混合气。     

一种基于FIRE滤波器的遥感图像增强

探讨了模糊理论与遥感图像处理的内在联系；提出了一种基于FIRE滤波器的遥感图像模糊增强方法。针对此方法，进行仿真试验并与其他方法进行了对比分析与评价，此方法表现出明显的优越性。     

基于AVL FIRE柴油机燃用生物柴油的数值模拟

利用AVL FIRE软件对JX493ZLQ3柴油机燃用柴油、B20、B50、B100的喷雾特性和燃烧特性进行数值模拟。模拟结果表明:生物柴油的雾化效果较差,并且生物柴油的高十六烷值、低热值较小等原因,其压力升高率要比较平缓,可以使柴油机工作更柔和,噪音也有所下降,并且生物柴油含氧,可以改善燃烧,但在生物柴油掺混量较高时,动力性有所下降。而在柴油中掺混少量生物柴油对柴油机的动力性及经济性都有所帮助。更多还原     

The Influence of FRW-1 Fire Retardant Treatment on the Bonding of Plywood

In this work the influence of FRW-1 fire retardant treatment on the bonding strength of plywood was studied. The results showed that the bonding strength of FRW-1 fire-retardant-treated Poplar plywood decreased by 25.3% as compared to untreated plywood; furthermore, free formaldehyde in the fire-retardant-treated Poplar plywood decreased by 64.9% when compared to untreated plywood. In our studies we also analyzed: the pH value and the buffering capacity of fire-retardant-treated and untreated wood powder; and the influence of FRW-1 fire retardant treatment on the gelation time of urea-formaldehyde (UF) adhesives. The results show that FRW-1 fire retardants reduced the pH value and increased the buffering capacity of FRW-1 fire-retardant-treated wood powder. The gelation time of the UF adhesive mixed with FRW-1 fire-retardanttreated wood powder was shortened by 15% as compared with the untreated wood powder. The results of the scanning electron microscope analysis showed that the FRW-1 fire retardant was mainly confined to: the trachea lumen of the Poplar wood; the wall of trachea; as well as around the pits when using an impregnation method at ambient temperature and pressure. It is possible that this has led to the decrease in mechanical action between the veneer and the adhesive.     

国外新型互联网试验床建设展望

介绍美国、欧盟、日本正在进行的几个新型互联网试验床建设研究项目的进展情况,着重探讨了PlanetLab、FIRE、CoreLab组织实施形式和研究进展,分析了它们的技术特征和发展趋势.     

基于FIRE的柴油机燃烧过程模拟分析

应用AVL的FIRE软件,对6105柴油机最大扭矩工况和标定工况时的缸内喷雾及燃烧过程进行了三维模拟计算,根据计算结果,分析了燃烧室内燃油喷雾的流场分布和燃烧进程.模拟计算及分析结果可为柴油机燃烧过程的完善提供有价值的参考依据.     

某增压汽油机进气过程流体流动特性研究

采用瞬态可压缩黏性流体微分方程和标准k-ε双方程紊流模型对某增压汽油机进气过程的流体流动特性进行数值模拟。计算结果表明,缸内瞬时温度和压力的变化,主要受到气缸内壁和新鲜充量传热以及活塞运动的影响,而进气道内瞬时温度的变化与进气道内气流运动的湍流强度密切相关。因此,要提高该汽油机的充量系数,最合理的办法是抑制进气道内的湍流强度。     

A novel membrane transport model for polymer electrolyte fuel cell simulations

This work presents the development of a 1D model describing water and charge transport through the polymer electrolyte membrane (PEM) in the fuel cell. The considered driving forces are electrical potential, concentration and pressure gradients. The membrane properties such as water diffusion and electro-osmotic coefficients, water sorption and ionic conductivity are treated as temperature dependent functions. The dependencies of diffusion and electro-osmotic coefficients on the membrane water concentration are described by linear functions. The membrane conductivity is computed in the framework of the percolation theory under consideration that the conducting phase in the PEM is formed by a hydrated functional groups and absorbed water. This developed membrane model was implemented in the CFD code AVL FIRE using 1D/3D coupling. The simulated polarization curves at various humidification of the cathode are found in good agreement with the experiments thus confirming the validity of the model.