The longitudinal aerodynamics of agriculture aircraft during low-altitude flight operation was analyzed. And the longitudinal static stability criterion in ground effect was discussed, including the effects of major aerodynamic derivatives on longitudinal static stability. By the five-order small-disturbance linear equation in ground effect, the influence on the mode properties of agriculture aircraft during low-altitude flight operation was computed. And the approach of mode vectors was used to investigate the dynamic stability, which is useful to understand the major variables acting in different modes. The longitudinal dynamic stability was analyzed by Routh's criteria. To ensure dynamic stability, the favorable position of the center of gravity was deduced by approximations. The results show that the longitudinal aerodynamics and stability influenced by ground effect should not be ignored for the agriculture aircraft during low-altitude flight operation.
Zerihan J,Zhang Xin. Aerodynamics of a single element wing in ground effect . AIAA 2000-0650, 2000
Ahmed M R, Takasaki T, Kohama Y. Aerodynamics of a NACA 4412 airfoil in ground effect[J].AIAA Journal.2007, 45(1):37-47
Gera J.Stability and control of wing-in-ground effect vehicles or wingships . AIAA1995-0339, 1995
Chun H H, Chang C H. Longitudinal stability and dynamic motion of a small passenger WIG craft[J].Ocean Engineering.2002, 29:1145-1162
Kornev N,Matveev K. Complex numerical modeling of dynamics and crashes of wing-in-ground vehicles . AIAA 2003-600, 2003
�ź���,¥����,��ΰ��.��Ч�������ȶ�����������о�[J].�Ϻ���ͨ��ѧѧ��, 1999, 33(3):361-364 Zhang Hongling, Lou Liangen, Zhou Weilin.Longitudinal stability and maneuverability of wing-in-ground effect vehicles[J]. Journal of Shanghai Jiaotong University, 1999, 33(3):361-364(in Chinese)
����ƽ,����,�����.���շ��������ж���ѧ[M].����:�������պ����ѧ������, 2005 Fang Zhenping, Chen Wanchun, Zhang Shuguang. Flight dynamics of aircraft[M]. Beijing:Beijing University of Aeronautics and Astronautics Press, 2005 (in Chinese)