升力浮力复合型飞艇动导数分析

Dynamic derivative analysis for hybrid airship incorporating lift and buoyancy

计算了球体和椭球体的平移、转动加速度导数,数值模拟了NACA0015翼型的俯仰振荡,验证了计算流体动力学(CFD)方法计算动导数的有效性.模拟升力浮力复合型飞艇的强迫振荡运动,得到了全艇以及机翼、艇身、平尾和垂尾的动导数,并与常规飞艇进行了比较分析.机翼对速度导数的贡献导致复合型飞艇升沉速度导数、滚转角速度导数较常规飞艇显著增大.常规飞艇加速度导数以惯性力成分为主,但黏性力成分以及机翼对艇身和尾翼的干扰对复合型飞艇升沉、滚转和俯仰3个方向的加速度导数有重要影响,不能将加速度导数简化为附加质量系数.

Translational and rotational acceleration derivatives of sphere and ellipsoid were calculated,and pitch oscillation of the NACA0015 airfoil was simulated.The applicability of computational fluid dynamics（CFD） method was validated.Forced oscillation of hybrid airship incorporating lift and buoyancy was simulated.The dynamic derivatives of whole airship,wing,hull,horizontal tail and vertical tail were obtained.The results were compared with those of conventional airship.The heave and roll velocity derivatives are much larger than those of conventional airship due to the contribution of wing.The viscous force and the interference of wing on hull and tail are important for the acceleration derivatives in the heave,roll and pitch directions.Consequently,the acceleration derivatives can not be simplified as additional mass coefficients.