For pure pitching motion, the results show that average drag coefficient decreases as airfoil thickness is reduced.
在低雷诺数条件下，对于纯俯仰运动，随着翼型厚度的减小，平均阻力系数也变小。
2
The circular arc automatic door is reciprocating swing, and its motion parameters are the number of swing per minute, the size of the swing Angle and the travel speed ratio coefficient.
圆弧形自动门是往复摆动，其运动参数是每分钟摆动次数、摆角大小和行程速比系数等。
3
Based on the achievements obtained. the theoretic formula that determine the rut size of the caterpillar tractor and the friction drag coefficient of motion was deduced.