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基于改进三阶段法的快速出口滑行道转出位置的确定方法研究 被引量:7
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作者 李明捷 王汝昕 《科学技术与工程》 北大核心 2014年第36期234-237,共4页
快速出口滑行道的设置是一种既经济又有效的用于提高跑道容量的方法,对提高机场运行效率有重要意义。论文将飞机自跑道入口至接地转出划分成三个阶段,分别为空中段、减速段与转出段。在分析三个阶段对应长度影响因素的基础上,针对某机... 快速出口滑行道的设置是一种既经济又有效的用于提高跑道容量的方法,对提高机场运行效率有重要意义。论文将飞机自跑道入口至接地转出划分成三个阶段,分别为空中段、减速段与转出段。在分析三个阶段对应长度影响因素的基础上,针对某机场运行的典型机型,运用三阶段法对不同风力负荷条件下各阶段长度进行计算,最后引入机型累计运行比例的概念,确定快速出口滑行道的最终转出位置及条数,总结了三阶段法的计算步骤。实例验证该方法的可行性,对机场平面设计有一定的借鉴价值。 展开更多
关键词 快速口滑行道 三阶段法 转出速度 最佳 最佳区域
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嘉陵江中下游地区近30年土地利用与覆被变化过程研究 被引量:50
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作者 仙巍 邵怀勇 周万村 《地理科学进展》 CSCD 北大核心 2005年第2期114-121,共8页
应用遥感和GIS技术及数理统计学的方法,利用1972年M SS遥感影像、1986年和2000年的TM遥感影像,在总结了目前使用较广泛的土地利用类型动态度模型的基础上,提出了转出速度、转入速度、综合动态度、状态指数等模型,并指出唯有将这些模型... 应用遥感和GIS技术及数理统计学的方法,利用1972年M SS遥感影像、1986年和2000年的TM遥感影像,在总结了目前使用较广泛的土地利用类型动态度模型的基础上,提出了转出速度、转入速度、综合动态度、状态指数等模型,并指出唯有将这些模型综合运用,才能更好地理解土地利用类型的动态变化。利用上述模型以及LUCC的幅度、区域差异模型,深入而全面的研究了自上世纪70年代初期以来嘉陵江中下游地区14个县市区LUCC的过程。 展开更多
关键词 土地利用与土地覆被变化 转出速度 速度 平衡状态 嘉陵江中下游地区
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Output Speed and Torque of Differential Double-Stator Swing Hydraulic Multimotors
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作者 闻德生 蔡秋雄 +1 位作者 马洪胜 高俊峰 《Journal of Donghua University(English Edition)》 EI CAS 2013年第6期487-493,共7页
A new type of differential double-stator swing hydraulic motor, based on double stator structure, was introduced. Compared with the traditional swing hydraulic motors, it could provide various kinds of rotational spee... A new type of differential double-stator swing hydraulic motor, based on double stator structure, was introduced. Compared with the traditional swing hydraulic motors, it could provide various kinds of rotational speeds and torques under the same conditions of input flow rate and pressure. The operating prindple and graphic symbols were described. The output speed and torque characters in multifarious connection modes were analyzed through single-acting differential double-stator swing hydraulic multi-motors. Then the differential connection modes and differential principles of differential double-stator swing hydraulic multi-motors were stated. Furthermore, the output speed and torque characters of double- acting and triple-acting ones in multifarious connection modes were gotten. The interaction between output torque and the displacement ratio was studied. Finally, the internal leakage that influenced the volumetric efficiency was researched. The theoretical and experimental researches show that the differential double-stutor swing hydraulic multi-motors can provide various kinds of rotational speeds and torques. Predictably, this new kind of swing hydraulic multi-motors has broad application prospects in machine tool equipments, engineering machineries, and simulation turntables. 展开更多
关键词 swing hydraulic motors DOUBLE-STATOR differential connection TORQUE rotational speed
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Flow Fields with Vortex in a Small Semi-open Axial Fan 被引量:12
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作者 Norimasa. Shiomi Yoichi Kinoue +2 位作者 Ying zi Jin Toshiaki Setoguchi Kenji Kaneko 《Journal of Thermal Science》 SCIE EI CAS CSCD 2009年第4期294-300,共7页
In order to clarify the effect of tip clearance (TC) size on fan performance and the flow field at rotor outlet in a small semi-open axial fan, the experimental investigation was carried out. The tip diameter of tes... In order to clarify the effect of tip clearance (TC) size on fan performance and the flow field at rotor outlet in a small semi-open axial fan, the experimental investigation was carried out. The tip diameter of test fan rotor was 180mm and test TC sizes were lmm (TC=1mm) and 4mm (TC=4mm). Fan characteristics tests were carried out for two cases of TC size and three-dimensional velocity fields at rotor outlet were measured using a single slant hot-wire probe at four flow-rate conditions. As a result, it was found that the pressure - flow-rate characteristics curves for two cases showed almost the same tendency. However, the ensemble averaged velocity profiles along radial measurement stations of TC-4mm largely changed compared with that of TC=1mm in cases of small flow-rate condition. From the phase-locked averaging results, it was also found that the vortex existed in the rotor outlet flow field of high flow-rate condition for each TC case. Compared with the vortices for TC=1mm and TC=4mm, the vortex for TC=4mm was stronger than that for TC=1mm. 展开更多
关键词 FAN semi-open type VORTEX tip clearance
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