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Numerical simulation of internal flow field in air–water transition process of transmedium engine 认领 引用
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作者 Conglin LIU Huanting JIANG +2 位作者 Xiaobo FANG Hong CHEN Changmeng LIU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第5期281-297,共17页
Transmedium vehicles are characterised by high flexibility and strong attack capability,which makes them a key area of current research.However,the transition between air and water remains a critical outstanding issue... Transmedium vehicles are characterised by high flexibility and strong attack capability,which makes them a key area of current research.However,the transition between air and water remains a critical outstanding issue.The ramjet integrated air–water engine designed in this study is effective and stable in both air and water modes and shows a high degree of adaptability.Using three-dimensional numerical simulations,this study investigates the impact of intake configurations and environmental pressure variations on engine performance,with a focus on the distribution of internal flow field parameters and performance changes during the transition process.The results show that,although the secondary air intake configuration in air mode effectively improves the engine thrust,it causes the front part of the engine to overheat,resulting in a reduction in overall power.The primary intake configuration is more favorable for ensuring a safe transition.During the descent of a vehicle from high altitude,the pressure of the engine's exhaust tailpipe gradually increases,and the combustion products move to the front of the engine,resulting in a significant loss of power.The entire air–water transition process takes 0.3 s.To ensure the stable transition of the engine's thrust,this paper proposes a preloaded oxidizer supply control scheme,which injects the preloaded oxidizer within 0.012 s after transition,opens the water intake at 0.205 s,and achieves the engine's design performance for underwater mode at 0.3 s,after which the oxidizer injection is stopped.This scheme significantly improves the efficiency of the transition process and enhances engine stability.The results of this study provide theoretical support for the design and optimization of air–water transition in transmedium ramjet engines. 展开更多
关键词 Air-water transition Internal flow field Preloaded oxidizer supply scheme Ramjet engine Transmedium
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基于倾转电机的可折翼的水空两栖无人机设计与实现 认领 引用 被引量:5
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作者 刘阳 王开松 +4 位作者 唐威 秦可成 张涛 杨展 邹俊 《机械工程学报》 EI CAS CSCD 北大核心 2024年第2期272-286,共15页
由于兼具着水下航行与空中飞行能力,近年来水空两栖无人机走入人们的视角。针对现有水空无人机面对复杂场景(水空界面、室内等)无法发挥作用的问题,提出一种结合旋翼机、固定翼与折翼机构的水空两栖无人机。设计一种基于倾转电机的三旋... 由于兼具着水下航行与空中飞行能力,近年来水空两栖无人机走入人们的视角。针对现有水空无人机面对复杂场景(水空界面、室内等)无法发挥作用的问题,提出一种结合旋翼机、固定翼与折翼机构的水空两栖无人机。设计一种基于倾转电机的三旋翼机构与基于舵机操控的折翼机构,利用倾转机构与折翼机构来实现固定翼与旋翼的模式切换以达到鸟类的飞行状态。对于自然界内的鸟类来说,翅膀的控制是十分重要的。在空中绝大部分鸟类都是利用翅膀的收折来控制飞行的转向与高度;当鸟类将要入水或者已经入水时,许多鸟类都是将翅膀完全收起以减小阻力面积来入水或者在水下运动。效仿鸟类收翅原理来设计折翼结构与倾转旋翼结构,使水空两栖无人机可实现旋翼与固定翼自由变换。为验证结构的可靠性,对无人机结构进行理论分析与仿真试验,以及空中与水下等复杂场景试验,试验结果表明,该无人机在空中可实现旋翼与固定翼的自由切换,在水下可实现水空界面的跨介质飞行,这些结果验证了方案的可行性与有效性。 展开更多
关键词 跨介质无人机 倾转旋翼 折翼设计
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从遵崇公路开通大型报道谈打造广播动态平台 认领 引用
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作者 滕明艳 《遵义师范学院学报》 2008年第6期41-44,共4页
媒体竞争激烈的时代,要提高广播的接受率,就必须紧紧围绕广播的特点,打造出最能体现广播特色、最大限度发挥广播优势的报道形式。广播和其他媒体比起来,是传统媒体中传播速度最快、最能有效进行互动的媒介。只要抓住"互动"这... 媒体竞争激烈的时代,要提高广播的接受率,就必须紧紧围绕广播的特点,打造出最能体现广播特色、最大限度发挥广播优势的报道形式。广播和其他媒体比起来,是传统媒体中传播速度最快、最能有效进行互动的媒介。只要抓住"互动"这个特点,在广播与听众间、广播媒体间、广播与其他媒体间打造"动态平台",就能让广播的节目听起来更加生动,更富有感染力。这对广播提高自身竞争力,增强广播节目的可听性会起到积极的促进作用。 展开更多
关键词 传受互动 动态平台 跨区域联合 跨媒体协作
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