The aeroelastic effects on the scatter phenomenon of wind-tunnel data

The unsteady Reynolds-averaged Navier-Stokes equations coupled with the k SST turbulence model are solved to obtain the steady and unsteady aerodynamic forces for airfoils and wings.The effects of vibration types and amplitudes on aerodynamic forces of airfoils and wings are studied.The deformation characteristics of a swept wing induced by steady aerodynamic load are presented.It is found that for a vibrating elastic wing at small and medium incidences,its mean aerodynamic loads are almost the same as those obtained from the static one.On the contrary,at high incidences especially around the stall incidence,the vibration may change the mean values.In addition,the larger amplitude is,the larger discrepancy will be.For a swept wing,the steady aerodynamic loads usually lead to the "pitching down" effect on the wing tip which delays the stall compared with a rigid one;But this phenomenon dose not occur on a aeroelastic wing which can induce the separation ahead and trigger the stall.The above conclusions are in good agreement with the scatter characteristics of wind-tunnel data.The reason why the data obtained from wind tunnel and CFD are different is also analyzed.Meanwhile,it can be an explanation for scatter phenomenon of wind-tunnel data,especially for high incidence cases,which remains a puzzle so far.     

龙开口水电站枢纽工程关键技术研究

龙开口水电站枢纽采取主河床泄洪、右岸坝后厂房布置形式,大坝为碾压混凝土重力坝.大坝的防震抗震,右岸变形体边坡治理,骨料料源选择、加工及运输,河中深槽处理,施工导流技术,泄洪消能技术,尾水渠粉质边坡治理等问题是工程建设的关键技术问题.针对这些问题,在可研、招标及技施阶段开展了大量研究工作,取得了许多有价值的成果,最终制定了合理的设计方案,为工程建设提供了技术保障.     

80 kt/a硫铁矿制酸扩建装置采用的新技术措施

针对采用水洗净化工艺的某80kt/a硫铁矿制酸装置的扩建设计，介绍了其中主要改扩建工段及设备采用的新技术措施，设计中对原料工段、沸腾炉、文氏管、泡沫塔、转化器、换热器等进行了改进，满足了厂方两期建设产量不同的要求。     

Effect of FTY720 and ICAM-1 mAb mono and combination therapy in cardiac allo-transplantation in rats

Objective To observe the effect of FTY720 and ICAM-1 mAb mono and combination therapy in cardiac silo-transplantation in rats. Methods Rats were randomly assigned to 9 groups, heart allo-transplantation were performed in abdominal site with micro-surgical technique. Recipients with allografts were treated with different doses of FTY720 and(or) ICAM-1 mAb. Graft survival, histopathology andlevel of serum IL-2, IFN-γ, IL-4, IL-10were investigated. Results Low doses of FTY720 (lmg/kg) combined with ICAM-1 mAb achieved synergistic effect in the prolongation of cardiac graft survival, combination index(CD =0.67. Conclusion Concomitant therapy of FTY720 and ICAM-1 mAb achieved a synergistic effect in the prolongation of heart allograft survival in rats.     

低温冰箱内温度场的有限元分析

认为有限元分析方法FEM(funite elementmethod)是一种应用非常广泛的数值计算方法;介绍了ANSYS有限元分析软件,并利用ANSYS软件对一台低温冰箱内的温度场进行计算和分析;提出了优化箱内温度场均匀分布的措施.     

非线性系统平稳分岐解镇定的简化原理

研究了一类具有线性不可控模态的非线性系统平稳分岐解的镇定问题.假定系统参数不可测量.基于不变流形理论,从原非线性系统导出了一个一维的简化方程.从简化方程的性质导出了原系统能分岐镇定的一些充分和必要条件.并举例说明了此方法的有效性.     

基于CMAC的电液负载模拟器自学习控制

通过建立某飞行器舵机电液负载模拟器与操舵系统联动的数学模型，分析了电液负载模拟器的多余力产生原理。提出了采用结构不变性原理设计补偿环节的基于CMAC神经网络的控制结构和算法。通过对系统的动态仿真表明，该方法可有效地抑制多余力，明显改善电液负载模拟器的动态加载性能。     

基于FreeSWAN的网络安全研究和VPN的构建

随着电子商务、政府上网工程、虚拟企业等的发展，对如何在公网上架构虚拟私有网(VPN)有日益迫切的需求．我们对免费的FreeSWAN软件进行了二次开发，利用我们研制的客户端VPN软件NetGuard能方便、经济、灵活地建立自己的VPN网络．本文对FreeSWAN的编译、安装、配置，以及管理等进行了详细的分析和讨论．     

提高虚拟空间会议系统服务质量QoS的若干技术

虚拟空间会议系统是视频会汉系统发展的最高形式．本文结合作者研究工作，通过分析与视频会议系统服务质量相关的技术，提出了基于VST系统的相关技术策略，这些策略能够有效地提高VST系统的服务质量．     

无刷直流电动机的设计(23)

9．3转矩系数Km和反电势系数Ke的计算公式 无论在电动机的设计技术领域，还是在电动机的应用技术领域，转矩系数Km和反电势系数Ke是两个评价电动机性能的重要技术指标。