نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشجوی دکتری، دانشگاه تهران، تهران، ایران
2 دانشیار،دانشگاه تربیت مدرس، تهران، ایران
3 دانشیار، دانشگاه تهران، تهران، ایران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
In the present study, a general introduction of a flapping wing is given by combining parts of a solid and a shell wing with a dominant plunge motion. In this experimental study, air flow velocity, flapping frequency, and angle of attack are considered as input variables. Composite wings with different span lengths and stiffness were designed and built. The variations of the thrust coefficient with respect to the reduced frequency with the angle of attack contours are measured and plotted. Also, the lift coefficient curves with respect to the angle of attack for the reduced frequency contours are measured and displayed. Both of these curves and performance indices are measured at speeds of 5 to 10 m/s. In order to reduce the measurement error including hysteresis and drift error in force measurement, the technique of difference between two states of fixed wing and flapping wing conditions has been used. The extracted graphs show the relationship between kinematic parameters such as speed, flapping frequency, angle of attack with performance indices such as lift and thrust coefficient. In addition, the flexibility of the shell wing has been changed by changing the number of ribs and the span of the shell wing. The results showed that the flexibility of the shell section has a direct effect on the thrust and thrust power, while the presence of the bulk section mainly increases the lift. This experimental study has shown that the bulk shell composite structure can have better aerodynamic efficiency and thrust efficiency.
کلیدواژهها [English]
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