Micro turbine engine （MTE） is an important kind of propulsion system for miniature unmanned aircraft or missiles, because of its better high-speed performance （than propeller propulsion） and higher propulsion effi...Micro turbine engine （MTE） is an important kind of propulsion system for miniature unmanned aircraft or missiles, because of its better high-speed performance （than propeller propulsion） and higher propulsion efficiency （obviously than rockets）. Windmill start is a common air-starting mode used in micro turbine engine. The windmill starting characteristics are important to the practical use of micro turbine engine. In this paper, the windmill starting characteristics research for a 12 cm diameter （MTE-D） micro turbine engine is carried out by experiment and numerical simulation. The characteristic of rotor mechanical losses at low-speed condition is stud- ied, and the engine common working line of windmill starting process is obtained. Based on the engine windmill characteristics, the propane ignition characteristics under different inflow conditions are researched, and the envelope of propane ignition and propane flameout is determined. The experimental research of fuel supply and ignition characteristics is completed, and the envelope of fuel supply and ignition is obtained. The windmill stage, propane ignition stage, fuel ignition stage and acceleration process from idling-speed to 80% full speed of MTE-D micro turbine engine is optimized, and the optimization windmill starting parameters are collected. The successful wind-mill starting experiment under this condition with engine speed up to 80% full speed indicates that these starting parameters are reasonable. All the starting parameters of MTE-D micro turbine engine obtained in this work are dimensionless parameters, and the conclusions obtained in this study have some reference to other micro turbine engines with the similar structural form and starting process.展开更多
研究城市道路交叉口电动自行车行驶特征能够为拥堵治理和渠化改善提供量化依据。受设施环境、交通量及驾驶人行为等因素影响,电动自行车在停驻等候、启动加速和通过交叉口3个阶段呈现显著差异性特征。基于无人机航拍数据,采用Data From ...研究城市道路交叉口电动自行车行驶特征能够为拥堵治理和渠化改善提供量化依据。受设施环境、交通量及驾驶人行为等因素影响,电动自行车在停驻等候、启动加速和通过交叉口3个阶段呈现显著差异性特征。基于无人机航拍数据,采用Data From Sky交通轨迹分析软件提取基础数据,建立了包括停驻面积、机动车启动延误、电动自行车行驶速度和行驶轨迹膨胀度等关键参数的量化分析方法。以汕头市金砂路4个典型交叉口为例进行应用分析,结果表明:停驻等候阶段,停驻数量与面积呈非线性函数关系;启动加速阶段,当等候区位于机动车前方时,电动自行车停驻数量与机动车启动延误显著正相关,每10辆电动自行车造成0.6~0.9 s机动车延误;通过交叉口阶段,电动自行车85%位速度为23.5 km·h-1,且行驶轨迹膨胀度呈先增后稳的变化趋势。展开更多
文摘Micro turbine engine （MTE） is an important kind of propulsion system for miniature unmanned aircraft or missiles, because of its better high-speed performance （than propeller propulsion） and higher propulsion efficiency （obviously than rockets）. Windmill start is a common air-starting mode used in micro turbine engine. The windmill starting characteristics are important to the practical use of micro turbine engine. In this paper, the windmill starting characteristics research for a 12 cm diameter （MTE-D） micro turbine engine is carried out by experiment and numerical simulation. The characteristic of rotor mechanical losses at low-speed condition is stud- ied, and the engine common working line of windmill starting process is obtained. Based on the engine windmill characteristics, the propane ignition characteristics under different inflow conditions are researched, and the envelope of propane ignition and propane flameout is determined. The experimental research of fuel supply and ignition characteristics is completed, and the envelope of fuel supply and ignition is obtained. The windmill stage, propane ignition stage, fuel ignition stage and acceleration process from idling-speed to 80% full speed of MTE-D micro turbine engine is optimized, and the optimization windmill starting parameters are collected. The successful wind-mill starting experiment under this condition with engine speed up to 80% full speed indicates that these starting parameters are reasonable. All the starting parameters of MTE-D micro turbine engine obtained in this work are dimensionless parameters, and the conclusions obtained in this study have some reference to other micro turbine engines with the similar structural form and starting process.
文摘研究城市道路交叉口电动自行车行驶特征能够为拥堵治理和渠化改善提供量化依据。受设施环境、交通量及驾驶人行为等因素影响,电动自行车在停驻等候、启动加速和通过交叉口3个阶段呈现显著差异性特征。基于无人机航拍数据,采用Data From Sky交通轨迹分析软件提取基础数据,建立了包括停驻面积、机动车启动延误、电动自行车行驶速度和行驶轨迹膨胀度等关键参数的量化分析方法。以汕头市金砂路4个典型交叉口为例进行应用分析,结果表明:停驻等候阶段,停驻数量与面积呈非线性函数关系;启动加速阶段,当等候区位于机动车前方时,电动自行车停驻数量与机动车启动延误显著正相关,每10辆电动自行车造成0.6~0.9 s机动车延误;通过交叉口阶段,电动自行车85%位速度为23.5 km·h-1,且行驶轨迹膨胀度呈先增后稳的变化趋势。
