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....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.展开更多
A Lagrange dynamic model is established based on small-angle approximation to improve the simulation model for shipborne helicopter landing collision.To describe fuselage motion effectively,the proposed model consider...A Lagrange dynamic model is established based on small-angle approximation to improve the simulation model for shipborne helicopter landing collision.To describe fuselage motion effectively,the proposed model considers ship motion,the interaction of the tires with the deck,and tire slippage.A mechanism of sliding motion is built,and a real-time reliability analysis of the algorithm is implemented to validate the proposed model.Numerical simulations are also conducted under different operation conditions.Results show that the proposed dynamic model can simulate the collision motion of helicopter landing in real time.Several suggestions for helicopter pilot landing are likewise provided.展开更多
针对直升机着舰过程中的下滑进场环节,从流场环境对直升机飞行品质影响的角度出发,研究了直升机着舰策略。分析了下滑进场区域的流场分布,研究表明流场的分布与距离甲板的高度相关,高度越低,气流速度均值越大,且下洗气流主要集中在迎甲...针对直升机着舰过程中的下滑进场环节,从流场环境对直升机飞行品质影响的角度出发,研究了直升机着舰策略。分析了下滑进场区域的流场分布,研究表明流场的分布与距离甲板的高度相关,高度越低,气流速度均值越大,且下洗气流主要集中在迎甲板风方向的路线区域,对直升机的飞行品质造成影响。分析了不同甲板风(Wind on deck,WOD)条件下直升机平衡状态量,分别从旋翼所需功率、操纵量和机体姿态等方面对进场方式进行了研究,表明合理的进场方式有利于着舰安全。展开更多
基金supported by the Aviation Science Fund(20145784010)
文摘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.
基金supported by the Hebei Province“Giant Plan”,China(Grant No.4570031)the Hebei Province Natural Science Fund,China(Grant No.E2019203431)the Foundation for Innovative Research Groups of the Natural Science Foundation of Hebei Province,China(Grant No.E2020203174).
文摘A Lagrange dynamic model is established based on small-angle approximation to improve the simulation model for shipborne helicopter landing collision.To describe fuselage motion effectively,the proposed model considers ship motion,the interaction of the tires with the deck,and tire slippage.A mechanism of sliding motion is built,and a real-time reliability analysis of the algorithm is implemented to validate the proposed model.Numerical simulations are also conducted under different operation conditions.Results show that the proposed dynamic model can simulate the collision motion of helicopter landing in real time.Several suggestions for helicopter pilot landing are likewise provided.
文摘针对直升机着舰过程中的下滑进场环节,从流场环境对直升机飞行品质影响的角度出发,研究了直升机着舰策略。分析了下滑进场区域的流场分布,研究表明流场的分布与距离甲板的高度相关,高度越低,气流速度均值越大,且下洗气流主要集中在迎甲板风方向的路线区域,对直升机的飞行品质造成影响。分析了不同甲板风(Wind on deck,WOD)条件下直升机平衡状态量,分别从旋翼所需功率、操纵量和机体姿态等方面对进场方式进行了研究,表明合理的进场方式有利于着舰安全。
