涡流比对双燃料发动机燃烧过程影响的数值分析

利用数值模拟的方法研究了涡流比对柴油引燃天然气发动机燃烧速率的影响。计算软件为经过修改的KIVA-Ⅲ程序。计算对象为具有深盆形燃烧室的发动机。研究表明，当涡流比从0依次增加到2．5、5时，虽然缸内平均湍流强度增加。但最高湍流区湍流强度先升后降；由于燃烧速率赖于当地的湍流强度，而不是缸内的平均湍流强度。所以燃烧速率并不是一直随涡流比增大而增大。     

CNG/柴油双燃料车用发动机排放特性研究

通过用YZA102Q柴油机改装的CNG／柴油双燃料发动机进行燃用双燃料和纯柴油两种情况下的对比试验。对CNG／柴油双燃料发动机THC、CO、NOx和烟度的排放特性，以及空燃比、引燃油量、喷油提前角对双燃料发动机排放的影响进行了研究和分析。     

双离合器式自动变速器换挡特性研究

介绍了双离合式自动变速器工作原理，建立了换挡过程的数学模型，并对升、降挡的换挡特性进行了仿真与试验分析，为DCT的开发设计提供了参考依据。     

浅谈FAS双中心建设及设备维护

重点分析了西安局集团公司由2K数调主系统组网更新改造为FAS双中心网络的建设方法,并根据日常维护经验,列举了调度台通道故障处理、FASB简易故障判断及计表倒换试验、FASA和FASB系统与MSC之间的业务故障处理等.     

Hydroelastic analysis of oblique irregular waves with a pontoon-type VLFS edged with dual inclined perforated plates

The fluid-structure interaction of oblique irregular waves with a pontoon-type very large floating structure (VLFS) edged with dual horizontal/inclined perforated plates has been investigated in the context of the direct time domain modal expansion theory. For the hydroelastic analysis, the boundary element method (BEM) based on time domain Kelvin sources is implemented to establish water wave model including the viscous effect of the perforated plates through the Darcy’s law, and the finite element method (FEM) is adopted for solving the deflections of the VLFS modeled as an equivalent Mindlin thick plate. In order to enhance the computing efficiency, the interpolation-tabulation scheme is applied to assess rapidly and accurately the free-surface Green function and its partial derivatives in finite water depth, and the boundary integral equation of a half or quarter VLFS model is further established taking advantage of symmetry of flow field and structure. Also, the numerical solutions are validated against a series of experimental tests. In the comparison, the empirical relationship between the actual porosity and porous parameter is successfully applied. Numerical solutions and model tests are executed to determine the hydroelastic response characteristics of VLFS with an attached anti-motion device. This study examines the effects of porosity, submerged depth, inclined angle and gap distance of such dual perforated anti-motion plates on the hydroelastic response to provide information regarding the optimal design. The effects of oblique wave angle on the performance of anti-motion and hydroelastic behavior of VLFS are also emphatically examined.     

Dual extended Kalman filter for vehicle state and parameter estimation

The article demonstrates the implementation of a model-based vehicle estimator, which can be used for combined estimation of vehicle states and parameters. The estimator is realised using the dual extended Kalman filter (DEKF) technique, which makes use of two Kalman filters running in parallel, thus 'splitting' the state and parameter estimation problems. Note that the two problems cannot be entirely separated due to their inherent interdependencies. This technique provides several advantages, such as the possibility to switch off the parameter estimator, once a sufficiently good set of estimates has been obtained. The estimator is based on a four-wheel vehicle model with four degrees of freedom, which accommodates the dominant modes only, and is designed to make use of several interchangeable tyre models. The paper demonstrates the appropriateness of the DEKF. Results to date indicate that this is an effective approach, which is considered to be of potential benefit to the automotive industry.     

液化石油气／柴油双燃料发动机放热规律分析

利用CB366燃烧分析仪测录的液化石油气（LPG）／柴油双燃料发动机和原柴油机示功图，比较了LPG／柴油双燃料发动机和原柴油机的燃烧特性及负荷对二者的影响，分析了供油提前角、掺烧比两因素对最高燃烧压力、燃烧放热率、着火开始时刻等双燃料发动机燃烧特性的影响，得出了有关双燃料发动机燃烧特性的结论。     

酸性环境干湿循环条件下膨胀土的膨胀特性及微观作用分析

弄清酸雨及干湿循环共同作用下膨胀土的膨胀性能及其微结构与矿物成分的变化，对研究酸雨区膨胀土的基本性质劣化及工程问题意义重大。为此，以广西酸雨重灾区百色原状膨胀土为对象，模拟酸雨（pH=3，5，7）与干湿循环（n=1，2，3，4）两者共同作用的环境，开展了无、有荷膨胀率试验，并采用扫描电镜（SEM）、压汞仪（MIP）和X射线衍射仪（XRD）分析了该环境下试样的微结构及矿物成分的演变规律。研究结果表明：酸性环境使试样的膨胀率增大，溶液的pH值越小，膨胀率越大；随干湿循环作用次数的增加，不同溶液环境下试样的膨胀率均先增大后趋于稳定，且2次作用后的增幅最大；经酸性环境与干湿循环共同作用试样的膨胀率增大更多，溶液pH值为3和5，经2次干湿循环后其膨胀率比pH值为7的分别增长了24.7%和7.9%；上覆压力能明显抑制试样膨胀率的增长，设定测试压力越大，该值下降越显著。酸性环境与干湿循环共同作用下膨胀率增大的机理可通过微观结构分析作出解释：酸性环境作用下膨胀土中游离SiO₂，Al₂O₃，K₂O，MgO，CaO等胶结物出现不同程度的溶蚀和淋滤，削弱了叠聚体结构间的联结作用，使面面叠聚结构的排列趋于分散，微孔隙体积及数目不断增大，同时遭受干湿循环作用后，土中微孔隙加速发育，土颗粒与溶液水间化学反应更剧烈，致使其膨胀变形进一步增大。因此，酸雨重灾区的膨胀土工程建设，必须考虑酸性环境与干湿循环共同作用造成的膨胀土基本性质劣化的不利影响。     

西安动车段控制集中系统工程设计方案研究

针对西安动车段控制集中系统工程设计涉及专业广、相关系统多等特点,引起控制集中系统设计、施工、调试难度大等一系列问题,结合西安动车段控制集中系统工程主要特点,对工程主要功能结构进行研究,采取合理的合署办公及岗位设置方案、系统接口方案、配套终端设置方案以及系统调试开通的实施方案,并成功应用于西安动车段工程。     

双燃料发动机电力推进LNG船可燃气体探测系统设计简介

详细介绍了双燃料发动机电力推进LNG船可燃气体探测系统设计的基本要求,包括可燃气体探头及取样管在不同区域的布置情况及数量要求。所述内容不仅涉及LNG船本身的要求,也覆盖了其他类型的液化气体运输船的相关要求。