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Supercavitation is a revolutionary technique to achieve high drag reduction for underwater vehicle. It can help us to break through the conventional speed barrier. This article presents a numerical algorithm for ventilated supercavitation flow field based on mixture multiphase flow model, briefs the calculation results and compares them with that tested in high-speed water tunnel and towing tank. The mathematical model, its numerical calculation method, computational region and boundary conditions are discussed in detail. Some pertinent nondimensional parameters about the ventilated supercavitation, such as geometrical configuration of supercavity, drag coefficient and ventilation rate are investigated. Reynolds number is selected to predict gas ventilation rate instead of Froude number. Finally, based on the test and simulation results, a semi-empirical formula of the ventilation rate estimation suitable for different conical angle caritators is proposed. 相似文献
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日前,长春66千伏城网是由长变分网和北郊分网组成的。长变分网是由长春一次变和长春发电厂、汽车厂热电站及16条送电线路、10个二次变电所组成的,如图1所示。北郊分网是由北郊一次变和6条送电线路及3个二次变电所组成的,如图2所示。从1984年开始,长春市的电压质量管理被水电部列入全国35个重点城市之后,为了不断改善电压质量,尽快地达到部颁考核标准,在无功调节与调压方面做了一些工作。首先,安装了有载调压变压器及电力 相似文献
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通过多年来的事故教训,使我们逐渐认识到,供电网中所发生的重大系统事故,多数是因为电网中的重点设备发生故障、继电保护装置和开关失灵或电网运行结线方式不合理等原因造成的。对此,几年来我们在反事故斗争中,除了严格贯彻执行规程制度和反事故措施外,还围绕电网运行结线方式和重点设备运行情况,开展了监察工作,起到了防患于未然的作用。下面谈谈几点体会。一、掌握电网薄弱环节加强电网安全监察 相似文献
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