Model of Airflow Field on the Deck for Shipborne Helicopter Flight Dynamics Analysis

来源 :Transactions of Nanjing University of Aeronautics and Astron | 被引量 : 0次 | 上传用户:hubeijj111
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
For the research of helicopter/ship dynamic interface,the method of combining steady flow and stochastic flow is adopted to establish a flow field model applied to the flight dynamics analysis of shipborne helicopter.The steady flow is calculated by computational fluid dynamics(CFD)method,while the stochastic flow is composed of the compensation velocity derived from ship motion and turbulence above the deck.The accuracy of the proposed flow field model is verified by comparing the helicopter response in the proposed flow field with the results calculated by US Army′s Military Specifications(MIL)model which is commonly used in engineering.Meanwhile,it also shows the proposed flow field model is more appliable to flight dynamics analysis of shipborne helicopter.On that the basis,ship deck flow field is simulated at different sea conditions by adjusting the wind speed on the deck,mother ship movement and shipboard turbulence,etc.And helicopter angular rate response is calculated.The results show that the difference of dynamic stability between helicopter′s roll and pitch leads to the facts that the influence of above factors on the helicopter′s roll angular rate response is greater than that of pitch angular rate,that the frequency and amplitude of mother ship roll motion are much greater than those of pitch motion,and that the disturbance caused by roll motion on the air has greater influence on the helicopter response.The shipboard turbulence is the main disturbance factor that influences helicopter flight stability and its intensity determines the amplitudes of angular rate response. For the research of helicopter / ship dynamic interface, the method of combining steady flow and stochastic flow is taken to establish a flow field model applied to the flight dynamics analysis of shipborne helicopter. Steady flow is calculated by computational fluid dynamics (CFD) method while the stochastic flow is composed of the compensation velocity derived from ship motion and turbulence above the deck. The accuracy of the proposed flow field model is verified by comparing the helicopter response in the proposed flow field with the results calculated by US Army’s It is commonly used in engineering. Meanwhile, it also shows the proposed flow field model is more appliable to flight dynamics analysis of shipborne helicopter. On that the basis, ship deck flow field is simulated at different sea conditions by adjusting the wind speed on the deck, mother ship movement and shipboard turbulence, etc. And helicopter angular rate response is calculated. sults show that the difference of dynamic stability between helicopter’s roll and pitch leads to the facts that the influence of above factors on the helicopter’s roll angular rate response is greater than that of pitch angular rate, that the frequency and amplitude of mother ship roll motion are much greater than those of pitch motion, and that the disturbance caused by roll motion on the air has greater influence on the helicopter response. shipboard turbulence is the main disturbance factor that influenced helicopter flight stability and its intensity determines the amplitudes of angular rate response.
其他文献
河北女篮在2007年全国女篮乙级联赛中,经过八场比赛的较量,最终取得了四胜四负的成绩,无缘进入甲级队行列。河北女篮在联赛中较高的失误率,是影响该队最终比赛成绩的主要原因
经过30多年的社会经济发展,我国职业教育发展已达到空前的规模,取得了令人瞩目的成就,已初步构建具有中国特色的职业教育体系。然而,我们也必须清醒地看到,职业教育规模扩张背后隐
大江DJ110-81主要技术参数rn发动机型式:单缸风冷四冲程缸径×行程:52.4×49.5(mm) 排量:107ml标定功率:4.4kW(8000r/min)最大扭矩:5.7N·m(6000r/min) 润滑方式:压力飞溅离
翻转课堂作为一种先学后教、以评促教、以学定教的教学模式,改变了传统课堂的教学结构,使学生不再只是简单的、机械的接收教师的知识传授,教师也不再需要对同一个知识点进行
中学生的网络偏差行为已经日益成为一个重要网络社会问题,但是国内对中学生网络偏差行为的实证研究相对较少。为了探讨影响青少年网络偏差行为的因素,本研究采用问卷调查法对
学位
A combined arrival and departure scheduling problem is investigated for multi-airport system to alleviate the problem of airspace congestion and flight delay.Fi
兖州矿业(集团)公司济宁二号煤矿在复杂条件下的综采工作面安撤施工中采取了一系列的安全高效技术。采取大功率回柱绞车、专用卸车平台和多绞车调整防倒的技术,解决了63下07
Mechanical elastic wheel(ME-wheel)is a new type of non-inflatable safety tyre,and the structure is significantly different from traditional pneumatic tyre.In or
21世纪是网络的时代,随着网络在社会经济、政治、文化、军事等领域的作用日益明显,其安全隐患也愈加突出。由于互联网的“虚拟”特性,网民容易在思想上形成网络是个“无规则、无