This paper presents a compact XYZ micro-stage driven by an impact driving mechanism.A moving body is translationally actuated along the X-,Y-,and Z-axes in millimeter-scale range and with nanometer-scale resolution.Cr...This paper presents a compact XYZ micro-stage driven by an impact driving mechanism.A moving body is translationally actuated along the X-,Y-,and Z-axes in millimeter-scale range and with nanometer-scale resolution.Cr-N thin-film strain sensors are integrated into the micro-stage for closed-loop positioning.Closed-loop control is also carried out.The motion errors in six degrees of freedom are also investigated for this micro-stage.It is clarified by analysis of finite element method that rotational motion errors around the driving axis are caused by torques due to tensions from the elastic hinges of microstage.The mechanical structure of XYZ micro-stage to cancel out the torque generated is proposed and the second prototype is fabricated.Although the rotational motion error is successfully suppressed in the second prototype,a rotational motion error of more than 0.1°remains due to remaining torque and assembly error of the elastic hinges.Then,in order to reduce the rotational motion error,the prototype is designed in which the location of elastic hinges is single-layered.By designing a mechanical structure in which torque is suppressed,all rotational motion errors are successfully reduced to less than 0.05°in the prototype with single-layer hinges.展开更多
本文针对微型涡喷发动机的氢气分级微混燃烧室出口温度场进行优化,通过构建Work-bench和UG联合仿真优化方法,且基于近似模型和遗传算法,建立了多参数驱动的优化设计流程,获得了氢气微混燃烧室最优参数组合的掺混孔孔径和轴向位置,以及...本文针对微型涡喷发动机的氢气分级微混燃烧室出口温度场进行优化,通过构建Work-bench和UG联合仿真优化方法,且基于近似模型和遗传算法,建立了多参数驱动的优化设计流程,获得了氢气微混燃烧室最优参数组合的掺混孔孔径和轴向位置,以及关键参数对出口热点温度的影响规律,并针对最优方案详细分析了燃烧室内流场、组分场和温度场的演化规律。研究结果表明:高温区集中在微混单元出口的0~20 mm内,燃烧室出口热点受外壁孔径影响最为敏感,减小外火焰筒掺混孔径和增加内火焰筒掺混孔径有利于提升出口温度分布均匀性。最优方案中内、外火焰筒掺混射流涡长度分别达到了29 mm和34 mm,出口温度分布系数(Outlet Temperature Distribution Factor,OTDF)仅为0.13,NO_(x)排放为3×10^(-6)。展开更多
基金supported by JSPS KAKENHI Grant Numbers JP 15H05759 and JP 20H00211。
文摘This paper presents a compact XYZ micro-stage driven by an impact driving mechanism.A moving body is translationally actuated along the X-,Y-,and Z-axes in millimeter-scale range and with nanometer-scale resolution.Cr-N thin-film strain sensors are integrated into the micro-stage for closed-loop positioning.Closed-loop control is also carried out.The motion errors in six degrees of freedom are also investigated for this micro-stage.It is clarified by analysis of finite element method that rotational motion errors around the driving axis are caused by torques due to tensions from the elastic hinges of microstage.The mechanical structure of XYZ micro-stage to cancel out the torque generated is proposed and the second prototype is fabricated.Although the rotational motion error is successfully suppressed in the second prototype,a rotational motion error of more than 0.1°remains due to remaining torque and assembly error of the elastic hinges.Then,in order to reduce the rotational motion error,the prototype is designed in which the location of elastic hinges is single-layered.By designing a mechanical structure in which torque is suppressed,all rotational motion errors are successfully reduced to less than 0.05°in the prototype with single-layer hinges.
文摘本文针对微型涡喷发动机的氢气分级微混燃烧室出口温度场进行优化,通过构建Work-bench和UG联合仿真优化方法,且基于近似模型和遗传算法,建立了多参数驱动的优化设计流程,获得了氢气微混燃烧室最优参数组合的掺混孔孔径和轴向位置,以及关键参数对出口热点温度的影响规律,并针对最优方案详细分析了燃烧室内流场、组分场和温度场的演化规律。研究结果表明:高温区集中在微混单元出口的0~20 mm内,燃烧室出口热点受外壁孔径影响最为敏感,减小外火焰筒掺混孔径和增加内火焰筒掺混孔径有利于提升出口温度分布均匀性。最优方案中内、外火焰筒掺混射流涡长度分别达到了29 mm和34 mm,出口温度分布系数(Outlet Temperature Distribution Factor,OTDF)仅为0.13,NO_(x)排放为3×10^(-6)。
