Numerical investigation of cavitating flow behind the cone of a poppet valve in water hydraulic system

Computational Fluid Dynamics (CFD) simulations of cavitating flow through water hydraulic poppet valves were performed using advanced RNGk-epsilon turbulence model. The flow was turbulent, incompressible and unsteady, for Reynolds numbers greater than 43000. The working fluid was water, and the structure of the valve was simplified as a two dimensional axisymmetric geometrical model. Flow field visualization was numerically achieved. The effects of inlet velocity, outlet pressure, opening size as well as poppet angle on cavitation intensity in the poppet valve were numerically investigated. Experimental flow visualization was conducted to capture cavitation images near the orifice in the poppet valve with 30° poppet angle using high speed video camera. The binary cavitating flow field distribution obtained from digital processing of the original cavitation image showed a good agreement with the numerical result. Project supported by the National Natural Science Foundation of China (No. 59835160) and Scientific Research Foundation for Returned Overseas Chinese Scholars, State Education Ministry of China (No. 50175097)     

基于供需平衡理论对辽宁本科英语翻译专业发展问题的必要性研究

本论文围绕基于供需平衡视角下的辽宁高校英语翻译专业发展现状和提升路径两部分展开。本论文拟从教育学、社会学和管理学的视角审视目前辽宁高校英语翻译专业存在的问题。本研究主要是在借鉴教育经济学中人才供需理论的基础上,深入挖掘辽宁高校英语翻译专业自身的特点与性质以及市场供需之间的关系,以供需平衡的视角应对目前英语翻译专业发展的困境,进而找到优化学科发展,提升学生就业能力的路径。     

专业实验室实现开放的实践和探索

本文从多方面介绍了专业实验室的特点,开放时所面临的问题,并从实际出发,总结自己在实践探索中的一些经验,提出了解决的措施。     

教学投影机亮度变暗的解决方案

对投影机亮度变暗的原因与维修、维护的范围及效果进行了分析，提出了维护、维修的方案及成本预测。     

“三大基础”在青少年足球训练中的应用

结合青少年足球教学训练的重点和实践,提出了在教学训练中应注意的问题．强调“三大基础”的训练,应根据青少年的特点和其今后发展方向入手。力求做到在基础中突出重点,从而更好地完善训练方式,提高训练效果。     

做专家型的员工

每到年终的时候，当老板的总是要给优秀员工发一个大大的红包，这时做老板的常常会有类似的感慨：要是企业里的员工都能像小王一样，该多好啊，我们企业将会有多大的发展啊。而业绩落在小王后面的小李小赵也会在心里暗自思忖：我什么时候也能做到他那么好的表现呢?     

语文新课程教学要树立新观念

语文新课程教学要树立文化观念、审美观念、个性观念、时代观念、发展观念和创新观念,引导学生体味作品丰富的文化内涵,培养高尚的审美情趣,培养创新能力,发展健康个性,形成健全人格,为学生的终身发展奠定基础。     

《太平经》易学思想浅析

从元气本原论、天人关系论、阴阳矛盾论等方面分析 ,《太平经》体现了易学哲学的宇宙生成模式、宇宙结构模式和宇宙通变模式 ,对易学在汉代的发展产生了重要的推动作用。探讨《太平经》的易学思想 ,有助于我们正确认识其在中国古代易学史上的地位     

Clinical detection and movement recognition of neuro signals

INTRODUCTION Human limbs are complex, delicate systems.Their reconstruction, both for appearance and forfunction compensations, proves to be complicatedprojects. With the development of science and tech-nology, both researchers and disabilities hope to haveartificial limb much more perky, comfortable, dex-terous and effective. Although thousands of pros-thetic limbs are commercially available worldwide,most of them, from mechanical styles to electricstyles, from motion controlled t…     

法律基础课教学改革的实践

本文阐述了高等院校法律基础课的性质和地位 ,提出了法律基础课改革的措施。