CAJ | 학술논문

基于非定常面元/时间步进全展自由尾迹建立了旋翼/机身非定常气动干扰分析方法。方法中耦合了非定常面元法和时间步进自由尾迹，以准确模拟旋翼非定常气动力、旋翼尾迹及桨叶对机身的非定常干扰效应。为模拟前飞状态下具有升力的机身，将机身离散为汇/偶极子面元，并采用涡线镜像法模拟旋翼尾迹靠近机身表面产生的加速效应。通过计算前飞状态的 Maryland、ROBIN（Rotor Body INteraction）旋翼/机身干扰下的非定常压力分布，并与可得到的实验值、CFD 计算结果对比，验证方法的准确性。随后分析前飞速度、旋翼与机身距离对旋翼/机身非定气动干扰的影响。计算结果表明机身头部和中部非定常压力主要受桨叶的通过性影响，而机身尾梁主要受尾迹/机身干扰影响，机身非定常气动力频率为桨叶片数的倍频。随前飞速度的增加，机身非定常压力幅值增加，尾梁压力幅值先增加后减小；增加旋翼与机身距离将减小机身和尾梁非定常压力幅值。
기우비정상면원/시간보진전전자유미적건립료선익/궤신비정상기동간우분석방법。방법중우합료비정상면원법화시간보진자유미적，이준학모의선익비정상기동력、선익미적급장협대궤신적비정상간우효응。위모의전비상태하구유승력적궤신，장궤신리산위회/우겁자면원，병채용와선경상법모의선익미적고근궤신표면산생적가속효응。통과계산전비상태적 Maryland、ROBIN（Rotor Body INteraction）선익/궤신간우하적비정상압력분포，병여가득도적실험치、CFD 계산결과대비，험증방법적준학성。수후분석전비속도、선익여궤신거리대선익/궤신비정기동간우적영향。계산결과표명궤신두부화중부비정상압력주요수장협적통과성영향，이궤신미량주요수미적/궤신간우영향，궤신비정상기동력빈솔위장협편수적배빈。수전비속도적증가，궤신비정상압력폭치증가，미량압력폭치선증가후감소；증가선익여궤신거리장감소궤신화미량비정상압력폭치。
Unsteady aerodynamic load on helicopter fuselage is mainly due to aerodynamic interaction of rotor and fuselage.An unsteady panel/time-step full-span free-wake method is established to accurately pre-dict the rotor/fuselage unsteady aerodynamic interaction for the vibration load analysis of whole vehicle.The unsteady panel method is used to consider unsteady aerodynamics of rotors and fuselage,and the free-wake method is applied to accurately simulate dynamics of rotor wake.Helicopter fuselage is discretizated into source/doublet panels to simulate its lift in forward flight,and vortex line mirror method is adapted to ac-count acceleration phenomenon resulted from rotor wake close to fuselage surface.To validate the accuracy of this approach,unsteady rotor/fuselage aerodynamic interaction of Maryland and ROBIN modes are simu-lated in forward flight,and compared with measured data and CFD results.Finally,the influences of ad-vanced ratio,rotor-fuselage distance on unsteady aerodynamic interaction are analyzed.It is shown that the unsteady pressure of fuselage is mainly affected by rotor blade pass effect,while that of tail boom is mainly due to the interaction of rotor wake and fuselage,and the frequency of unsteady pressure is times of blades number.Amplitude of unsteady pressure on fuselage will increase as advance ratio increases,that of tail boom,however,will increase and then decrease.Increasing rotor-fuselage distance will decrease amplitude of unsteady pressure on fuselage and tail boom.