爆炸焊接斜碰撞过程的数值模拟

 借助动力学分析软件ANSYS/LS-DYNA 11.0,建立了考虑材料强度的流体弹塑性力学模型,运用光滑粒子流体动力学（SPH）方法,对爆炸焊接斜碰撞过程进行了数值模拟。界面波和射流的模拟结果与爆炸焊接生产实际中的现象较为吻合,说明采用SPH方法对爆炸焊接斜碰撞过程进行模拟研究是有科学价值的。     

实验楼火灾安全报警及联动控制系统设计

通过对实验教学楼存在火灾安全隐患的分析,对辽宁工程技术大学综合实验楼火灾自动报警系统、火灾探测器及手动报警按钮、火灾消防联动控制系统进行设计分析,提出了综合实验楼火灾报警及联动控制方案.研究表明,火灾安全报警及联动控制系统设计时除应按照报警及防火设计规范要求外,还应对具体的工程情况具体分析,采用更适用于工程特点的消防系统.设计者要多方面考虑综合因素,使报警准确、联动控制无误.真正做到"防患于未然",达到防灾、灭灾的目的,确保建筑物的安全使用.     

水射流-机械滚刀复合破岩影响因素

针对极硬岩、极端软硬不均等特殊地层,滚刀破岩效率低下,刀具磨损(损坏)严重,掘进机换刀频繁,作业效率低的问题,通过搭建水射流滚刀复合破岩实验系统,针对不同花岗岩,采用不同的机械滚刀间距及水射流辅助破岩方式,开展了纯机械滚刀破岩、水射流切割岩石和水射流机械滚刀复合破岩实验研究,探明了水射流与机械滚刀复合破岩水射流破岩切缝深度、刀具三向力及破岩比能变化规律,为水射流破岩技术在隧道掘进机工程应用提供指导。     

梁侧锚固钢板加固火后混凝土梁受弯试验研究

按照ISO834国际标准升温曲线对6根钢筋混凝土梁进行受火试验,并用梁侧锚固钢板法对其中5根受损梁进行加固,然后进行四点弯曲试验.分析了锚栓间距、角钢加劲肋、梁侧钢板的高度与厚度等因素对加固梁受弯承载力、刚度及延性的影响.结果表明:火灾后受损梁采用梁侧锚固钢板加固后,峰值荷载和刚度均得到显著提高,但其延性变化各异;受弯性能的加固效果随钢板厚度增大及锚栓间距减小而增强,而角钢加劲肋可有效限制钢板屈曲.通过限制钢板与混凝土连接界面上的相对滑移以及梁侧钢板的屈曲,可显著提高钢板与混凝土梁之间协同工作的程度.     

议灭火器的选型配置及监督管理

针对目前建筑灭火器在工程设计、施工、使用以及消防监督过程中存在的不同程度的缺陷,根据规范标准的相关要求,结合工程的实际,从以上方面提出提出相应的消防措施。     

高超声速飞行器反作用控制系统喷流干扰综述

反作用控制系统（reaction control system, RCS）在高超声速飞行器上取得了较为广泛的应用,已成为高超声速飞行器重要的控制手段之一. RCS 工作过程中喷流与来流形成了复杂的干扰流场,使得对RCS的控制能力预测存在困难. 根据RCS 在不同高超声速飞行器上的布局位置及飞行器局部外形特点将RCS 布局方式归纳为4 类,包括小曲率表面喷流、大曲率表面喷流、头部喷流和翼面附近喷流. 对用于模拟各布局方式流动特征的4 种典型模型进行了概述,并对各典型模型喷流干扰问题的研究进展进行了总结. 最后,对今后研究方向提出了一些建议.     

Numerical investigation of the flow and heat behaviours of an impinging jet

The flow and temperature fields of a turbulent impinging jet are rather complex. In order to accurately describe the flow and heat-transfer process, two important factors that must be taken into account are the turbulence model and the wall function. Several turbulence models, including κ–? turbulence models, κ–ω turbulence models, low-Re turbulence models, the κ–κ_l–ω turbulence model, the Transition SST turbulence model, the V2F turbulence model and the RSM turbulence model, are examined and compared to experimental data. Furthermore, for the near wall region, various wall functions are presented for comparison and they include the standard wall function, the scale wall function, the non-equilibrium wall function and the enhanced wall function. The distribution features of velocity, turbulent kinetic energy and Nusselt number are determined in order to provide a reliable reference for the multiphase impinging jet in the future.     

高速喷流下的柔性旋转火箭发射系统瞬态响应

对于柔性旋转火箭发射系统，考虑高速燃气喷流作用下的系统耦合振动．建立发射系统动力学模型，数值计算发射管流场结构，确定系统瞬态响应和燃气流冲击对火箭发射姿态的影响，更加真实地模拟柔性旋转火箭的发射动力学环境．     

Direct numerical simulation of a particle-laden low Reynolds number turbulent round jet

Direct numerical simulation method is used for the investigating of particle-laden turbulent flows in a spatially evolution of low Reynolds number axisymmetric jet, and the Eulerian–Lagrangian point-particle approach is employed in the simulation. The simulation uses an explicit coupling scheme between particles and the fluid, which considers two-way coupling between the particle and the fluid. The DNS results are compared well with experimental data with equal Reynolds number (R_e = 1700). Our objects are: (i) to investigate the correlation between the particle number density and the fluctuating of fluid streamwise velocity; (ii) to examine whether the three-dimensional vortex structures in the particle-laden jet are the same as that in the free-air jet and how the particles modulate the thee-dimensional vortex structures and turbulence properties with different Stokes number particles; (iii) to discover the particle circumferential dispersion with different Stokes number particles. Our findings: (i) all the particles, regardless of their particle size, tend to preferentially accumulate in the region with large-than-mean fluid streamwise velocity; (ii) the small Stokes number particles take an important part in the modulation of three-dimensional vortex structures, but for the intermediate and larger sized particles, this modulation effect seems not so apparent; (iii) the particle circumferential dispersion is more effective for the smaller and intermediate sized particles, especially for the intermediate sized particles.     

Convected level set method for the numerical simulation of fluid buckling

‘Fluid buckling’ is a phenomenon characterized mainly by the existence of fluid toroidal oscillations during flow. It appears when a high viscosity fluid flows vertically against a flat surface and may occur in industrial applications, as in injection molding of a propergol in complex‐shaped cavities. These coiling or folding oscillations appear during the mold filling stage, leading to air entrapment. To understand and to model this free surface flow problem, a convected level set method is proposed. First, a sinus filter is applied to the distance function to get a smooth truncation far from the interface. Second, the reinitialization is embedded in the transport equation model, avoiding it as a separate step during calculation. In order to validate the method, numerical results are presented on classical interface capturing benchmarks. Finally, results are shown on two‐dimensional and three‐dimensional viscous jet buckling problems. Copyright © 2010 John Wiley & Sons, Ltd.