The micro Flapping Rotary Wing （FRW） concept inspired by insects was proposed recently. Its aerodynamic performance is highly related to wing pitching and rotational motions. Therefore, the effect of wing pitching k...The micro Flapping Rotary Wing （FRW） concept inspired by insects was proposed recently. Its aerodynamic performance is highly related to wing pitching and rotational motions. Therefore, the effect of wing pitching kinematics and rotational speed on unsteady aerodynamic forces and power consumption of a FRW in hovering flight is further studied in this paper using computational fluid dy- namics method. Considering a fixed pitching amplitude （i.e., 80°）, the vertical force of FRW increases with the downstroke angle of attack and is enhanced by high wing rotational speed. However, a high downstroke angle of attack is not beneficial for acquiring high rotational speed, in which peak vertical force at balance status （i.e., average rotational moment equals zero.） is only acquired at a comparatively small negative downstroke angle of attack. The releasing constraint of pitching amplitude, high rotational speed and enhanced balanced vertical force can be acquired by selecting small pitching amplitude despite high power consumption. To confirm which wing layout is more power efficient for a certain vertical force requirement, the power consumed by FRW is compared with the Rotary Wing （RW） and the Flapping Wing （FW） while considering two angle of attack strategies without the Reynolds number （Re） constraint. FRW and RW are the most power efficient layouts when the target vertical force is produced at an angle of attack that corresponds to the maximum vertical force coefficient and power efficiency, respectively. However, RW is the most power efficient layout overall despite its insufficient vertical force production capability under a certain Re.展开更多
This study provides an overview of Building-Integrated Wind Turbines,focusing on cement silos as wind concentrators,along with determining the amount of power that could be connected without regard to wind direction.T...This study provides an overview of Building-Integrated Wind Turbines,focusing on cement silos as wind concentrators,along with determining the amount of power that could be connected without regard to wind direction.The motivation of this research is the intermittency issue of wind stream in an open environment and non-exploration of wind turbines between cement silos.Building-Augmented Wind Turbines provide 717 W of aerodynamic power at 16 m/s,whereas Standalone Wind Turbines produce 562 W.This is due to the wind speed acceleration between buildings,which causes a concentration effect.Meanwhile,using the simulation software ANSYS,the turbine geometry is developed utilising a Computational Fluid Dynamics evaluation.展开更多
基金Acknowledgment This research was primarily supported by the Na- tional Natural Science Foundation of China （Grant number： 11672022）.
文摘The micro Flapping Rotary Wing （FRW） concept inspired by insects was proposed recently. Its aerodynamic performance is highly related to wing pitching and rotational motions. Therefore, the effect of wing pitching kinematics and rotational speed on unsteady aerodynamic forces and power consumption of a FRW in hovering flight is further studied in this paper using computational fluid dy- namics method. Considering a fixed pitching amplitude （i.e., 80°）, the vertical force of FRW increases with the downstroke angle of attack and is enhanced by high wing rotational speed. However, a high downstroke angle of attack is not beneficial for acquiring high rotational speed, in which peak vertical force at balance status （i.e., average rotational moment equals zero.） is only acquired at a comparatively small negative downstroke angle of attack. The releasing constraint of pitching amplitude, high rotational speed and enhanced balanced vertical force can be acquired by selecting small pitching amplitude despite high power consumption. To confirm which wing layout is more power efficient for a certain vertical force requirement, the power consumed by FRW is compared with the Rotary Wing （RW） and the Flapping Wing （FW） while considering two angle of attack strategies without the Reynolds number （Re） constraint. FRW and RW are the most power efficient layouts when the target vertical force is produced at an angle of attack that corresponds to the maximum vertical force coefficient and power efficiency, respectively. However, RW is the most power efficient layout overall despite its insufficient vertical force production capability under a certain Re.
文摘This study provides an overview of Building-Integrated Wind Turbines,focusing on cement silos as wind concentrators,along with determining the amount of power that could be connected without regard to wind direction.The motivation of this research is the intermittency issue of wind stream in an open environment and non-exploration of wind turbines between cement silos.Building-Augmented Wind Turbines provide 717 W of aerodynamic power at 16 m/s,whereas Standalone Wind Turbines produce 562 W.This is due to the wind speed acceleration between buildings,which causes a concentration effect.Meanwhile,using the simulation software ANSYS,the turbine geometry is developed utilising a Computational Fluid Dynamics evaluation.
