期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
液压自由活塞发动机的气体流动模拟 被引量:4
1
作者 朱涛 汪洋 +1 位作者 张中 熊仟 《中国机械工程》 EI CAS CSCD 北大核心 2010年第18期2196-2201,共6页
基于Amesim建立了两行程自由活塞发动机模型,针对直流扫气特点提出了单区三阶段扫气模型,根据CFD计算结果对扫气参数进行了标定,在准确预测扫气性能的基础上分析了耦合活塞动力学条件下的气体交换过程。研究结果表明,当气口的配气相位... 基于Amesim建立了两行程自由活塞发动机模型,针对直流扫气特点提出了单区三阶段扫气模型,根据CFD计算结果对扫气参数进行了标定,在准确预测扫气性能的基础上分析了耦合活塞动力学条件下的气体交换过程。研究结果表明,当气口的配气相位角不变时,自由活塞发动机的气口面积随时间的变化关系与曲柄发动机的气口面积随时间的变化关系存在显著差异。气口高度减小对提高充气效率有利,但是受到扫气效率过分下降的约束。排气流动控制明显改善了扫气性能,利用排气脉动效应可以显著提高充气效率。 展开更多
关键词 自由活塞 扫气 时-面值 充气效率
下载PDF
On Light-Like Extremal Surfaces in Curved Spacetimes
2
作者 HUANG Shou-Jun HE Chun-Lei 《Communications in Theoretical Physics》 SCIE CAS CSCD 2014年第1期15-22,共8页
In this paper, we find that under a diffeomorphic of nonlinear geodesic equations are concerned with light-like extremal surfaces in curved spaeetimes. It is interesting to transformation of variables, the light-like ... In this paper, we find that under a diffeomorphic of nonlinear geodesic equations are concerned with light-like extremal surfaces in curved spaeetimes. It is interesting to transformation of variables, the light-like extremal surfaces can be described by a system Particularly, we investigate the light-like extremal surfaces in Schwarzschild spacetime in detail and some new special solutions are derived systematically with aim to compare with the known results and to illustrate the method. 展开更多
关键词 light-like extremal surfaces geodesic equations curved spacetimes Schwarzschild spacetime
原文传递
Evaporation of liquid fuel droplet at supercritical conditions 被引量:7
3
作者 HE Peng LI YunQing ZHAO LiFeng 《Science China(Technological Sciences)》 SCIE EI CAS 2011年第2期369-374,共6页
A comprehensive analysis of liquid fuel droplet evaporation at supercritical conditions is performed.The numerical model is based on complete time-dependent conservation equations,with a full account of variable therm... A comprehensive analysis of liquid fuel droplet evaporation at supercritical conditions is performed.The numerical model is based on complete time-dependent conservation equations,with a full account of variable thermophysical properties and vapor-liquid interfacial thermodynamics.And the model employs the Peng-Robinson(PR)equation of state(EOS).As a specific example,problems involving n-heptane droplet in nitrogen gas are investigated.The results indicate that the increase of ambient pressure and temperature results in the increase of surface temperature rise rate and surface regression rate.The transition from subcritical state to supercritical state can occur at the droplet surface when the droplet evaporates in a strongly supercritical environment. 展开更多
关键词 EVAPORATION fuel droplet supercritical conditions
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部