A new species of the genus Macromotettixoides Zheng, Macromotettixoides undulatifemura sp. nov. is described from the Emeishan Area of Sichuan, China. Type specimens are deposited at the Institute of Zoology, Shaanxi ...A new species of the genus Macromotettixoides Zheng, Macromotettixoides undulatifemura sp. nov. is described from the Emeishan Area of Sichuan, China. Type specimens are deposited at the Institute of Zoology, Shaanxi Normal University, Xi＇an, China.展开更多
Abstract： A new species, Systolederus choui sp. nov., from Jinggangshan, Jiangxi Province, China, is described. The new species is allied to Systolederusfujianensis Zheng and S. longinota Zheng, but differs in： 1）l...Abstract： A new species, Systolederus choui sp. nov., from Jinggangshan, Jiangxi Province, China, is described. The new species is allied to Systolederusfujianensis Zheng and S. longinota Zheng, but differs in： 1）length of pronotum 3.7-4.1 （ ♂）, 5.5-6.6 （♀） times as long as the portion surpassing apex of hind femur; 2） width of middle femur equal to width of tegmina in female; 3） length of third segment of posterior tarsi largerthan the first. The types are deposited in the Biological Museum, Sun Yat-sen University. This is the thirtieth known species of Systolederus in the world. A catalogue of all currently recognized species in the genus Systolederus is given.展开更多
One new species of the genus Mazarredia Bolivar, Mazarredia nigripennis sp. nov. is described. This new species can be distinguished from Mazarredia brachynota Zheng, 2005 by： 1） width of longitudinal furrow narrowe...One new species of the genus Mazarredia Bolivar, Mazarredia nigripennis sp. nov. is described. This new species can be distinguished from Mazarredia brachynota Zheng, 2005 by： 1） width of longitudinal furrow narrower than width of first segment of antennae; 2） with a pair short longitudinal keels between shoulders; 3） hind process of pronotum slightly surpassing the top of hind femora and reaching the base of hind tibia; 4） hind wings reaching the top of hind process; 5） width of midfemur wider than the width of tegmina. Type specimens are deposited in the Institute of Zoology, Shaanxi Normal University, China （2♂） and Department of Chemistry and Life Science, Hechi University, China （1 ♂）.展开更多
At low Reynolds numbers,the variable flexibility of flapping insect wings is considered essential in improving the favorable aerodynamic forces.To further explore whether significant aerodynamic coupling exists betwee...At low Reynolds numbers,the variable flexibility of flapping insect wings is considered essential in improving the favorable aerodynamic forces.To further explore whether significant aerodynamic coupling exists between the microstructure and passive flexible deformation,this paper proposes three technical comparison airfoils:a corrugated wing with deformation,a symmetric flat plate wing with deformation,and a corrugated wing without deformation.Based on STAR-CCM+software,this paper numerically solves the Navier-Stokes equations using the fluid-structure interaction method.The results show that the aerodynamic performance of the flexible corrugated wing is better than that of the rigid corrugated wing,and its lift and thrust are both improved to a certain extent,and the thrust efficiency of the flexible corrugated wing is significantly higher than that of the flexible flat plate.Although the thrust is improved,a part of the lift is lost,and as the flapping amplitude increases past 35°,the disparity gradually increases.A comparison of the flexible technical airfoils shows that the corrugated structure promotes thrust and retards lift,which is closely related to the formation and dissipation of strong vortex rings during the downstroke phase.On the premise of maintaining typical flapping without falling,dragonflies can fly with skillful efficiency by adjusting the way they flap their wings.The results of this work provide new insight into the formation and role of thrust in flapping maneuvering flight and provide a specific reference for developing new bionic flapping-wing aircraft.展开更多
A linearization method and an engineering approach for the geometric nonlinear aeroelastic stability analysis of the very flexi- ble aircraft with high-aspect-ratio wings are established based on the little dynamic pe...A linearization method and an engineering approach for the geometric nonlinear aeroelastic stability analysis of the very flexi- ble aircraft with high-aspect-ratio wings are established based on the little dynamic perturbation assumption.The engineering practicability of the method is validated by a complex example.For a high-altitude long-endurance unmanned aircraft,the nonlinear static deformations under straight flight and the gust loads are calculated.At the corresponding nonlinear equilibrium state,the complete aircraft is linearized dynamically and the vibration modes are calculated considering the large deformation effects.Then the unsteady aerodynamics are calculated by the double lattice method.Finally,the aeroelastic stability of the complete aircraft is analyzed.The results are compared with the traditional linear calculation.The work shows that the geometric nonlinearity induced by the large structural deformation leads to the motion coupling of the wing chordwise bending and the torsion,which changes the mode frequencies and mode shapes.This factors change the aeroelastic coupling relationship of the flexible modes leading to the decrease of the flutter speed.The traditional linear method would give not only an imprecise flutter speed but also a possible dramatic mistake on the stability.Hence,for a high-altitude long-endurance unmanned aircraft with high-aspect-ratio wings,or a similar very flexible aircraft,the geometric nonlinear aeroelastic analysis should be a necessary job in engineering practice.展开更多
基金supported by the National Natural Science Foundation of China (31160433)the Guangxi Natural Science Foundation (0991266)
文摘A new species of the genus Macromotettixoides Zheng, Macromotettixoides undulatifemura sp. nov. is described from the Emeishan Area of Sichuan, China. Type specimens are deposited at the Institute of Zoology, Shaanxi Normal University, Xi＇an, China.
基金supported by the Biodiversity of Mount Jinggangshan in China (2010330007102993)
文摘Abstract： A new species, Systolederus choui sp. nov., from Jinggangshan, Jiangxi Province, China, is described. The new species is allied to Systolederusfujianensis Zheng and S. longinota Zheng, but differs in： 1）length of pronotum 3.7-4.1 （ ♂）, 5.5-6.6 （♀） times as long as the portion surpassing apex of hind femur; 2） width of middle femur equal to width of tegmina in female; 3） length of third segment of posterior tarsi largerthan the first. The types are deposited in the Biological Museum, Sun Yat-sen University. This is the thirtieth known species of Systolederus in the world. A catalogue of all currently recognized species in the genus Systolederus is given.
基金The project is supported by the Guangxi Education Department Foundation of China (200607MS035)
文摘One new species of the genus Mazarredia Bolivar, Mazarredia nigripennis sp. nov. is described. This new species can be distinguished from Mazarredia brachynota Zheng, 2005 by： 1） width of longitudinal furrow narrower than width of first segment of antennae; 2） with a pair short longitudinal keels between shoulders; 3） hind process of pronotum slightly surpassing the top of hind femora and reaching the base of hind tibia; 4） hind wings reaching the top of hind process; 5） width of midfemur wider than the width of tegmina. Type specimens are deposited in the Institute of Zoology, Shaanxi Normal University, China （2♂） and Department of Chemistry and Life Science, Hechi University, China （1 ♂）.
基金the National Natural Science Foundation of China(Grant No.11862017).
文摘At low Reynolds numbers,the variable flexibility of flapping insect wings is considered essential in improving the favorable aerodynamic forces.To further explore whether significant aerodynamic coupling exists between the microstructure and passive flexible deformation,this paper proposes three technical comparison airfoils:a corrugated wing with deformation,a symmetric flat plate wing with deformation,and a corrugated wing without deformation.Based on STAR-CCM+software,this paper numerically solves the Navier-Stokes equations using the fluid-structure interaction method.The results show that the aerodynamic performance of the flexible corrugated wing is better than that of the rigid corrugated wing,and its lift and thrust are both improved to a certain extent,and the thrust efficiency of the flexible corrugated wing is significantly higher than that of the flexible flat plate.Although the thrust is improved,a part of the lift is lost,and as the flapping amplitude increases past 35°,the disparity gradually increases.A comparison of the flexible technical airfoils shows that the corrugated structure promotes thrust and retards lift,which is closely related to the formation and dissipation of strong vortex rings during the downstroke phase.On the premise of maintaining typical flapping without falling,dragonflies can fly with skillful efficiency by adjusting the way they flap their wings.The results of this work provide new insight into the formation and role of thrust in flapping maneuvering flight and provide a specific reference for developing new bionic flapping-wing aircraft.
基金supported by the National Natural Science Foundation of China(Grant Nos.90716006,10902006)the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20091102110015)
文摘A linearization method and an engineering approach for the geometric nonlinear aeroelastic stability analysis of the very flexi- ble aircraft with high-aspect-ratio wings are established based on the little dynamic perturbation assumption.The engineering practicability of the method is validated by a complex example.For a high-altitude long-endurance unmanned aircraft,the nonlinear static deformations under straight flight and the gust loads are calculated.At the corresponding nonlinear equilibrium state,the complete aircraft is linearized dynamically and the vibration modes are calculated considering the large deformation effects.Then the unsteady aerodynamics are calculated by the double lattice method.Finally,the aeroelastic stability of the complete aircraft is analyzed.The results are compared with the traditional linear calculation.The work shows that the geometric nonlinearity induced by the large structural deformation leads to the motion coupling of the wing chordwise bending and the torsion,which changes the mode frequencies and mode shapes.This factors change the aeroelastic coupling relationship of the flexible modes leading to the decrease of the flutter speed.The traditional linear method would give not only an imprecise flutter speed but also a possible dramatic mistake on the stability.Hence,for a high-altitude long-endurance unmanned aircraft with high-aspect-ratio wings,or a similar very flexible aircraft,the geometric nonlinear aeroelastic analysis should be a necessary job in engineering practice.
