The aerodynamic interaction between the contralateral wings and between the body and wings of a model insect are studied, by using the method of numerically solving the Navier-Stokes equations over moving overset grid...The aerodynamic interaction between the contralateral wings and between the body and wings of a model insect are studied, by using the method of numerically solving the Navier-Stokes equations over moving overset grids, under typical hovering and forward flight conditions. Both the interaction between the contralateral wings and the interaction between the body and wings are very weak, e.g. at hovering, changes in aerodynamic forces of a wing due to the present of the other wing are less than 3% and changes in aerodynamic forces of the wings due to presence of the body are less than 2%. The reason for this is as following. During each down- or up-stroke, a wing produces a vortex ring, which induces a relatively large jet-like flow inside the ring but very small flow outside the ring. The vortex rings of the left and right wings are on the two sides of the body. Thus one wing is outside vortex ring of the other wing and the body is outside the vortex rings of the left and right wings, resulting in the weak interactions.展开更多
We give the moment expressions for the boson resonances X with spin-parity JXPXC=0++,1-+,1++ and 2++ posibly produced in the process J/ψ→ρX，X→b1(1235)π，b1→ωπ in terms of the generalized moment analysis metho...We give the moment expressions for the boson resonances X with spin-parity JXPXC=0++,1-+,1++ and 2++ posibly produced in the process J/ψ→ρX，X→b1(1235)π，b1→ωπ in terms of the generalized moment analysis method .The resonance with JXPXC=1-+ can e distingguished from other resonances by means of these moments exceptfor some rather special cases.The suggestion that the search for the hybrid with IG(JPC)=1-(1-+) can be performed in the decay channl J/ψ→ρωππat upgraded BEPC/BES is presented.展开更多
基金supported by the National Natural Science Foundation of China(10732030)the 111 Project (B 07009)
文摘The aerodynamic interaction between the contralateral wings and between the body and wings of a model insect are studied, by using the method of numerically solving the Navier-Stokes equations over moving overset grids, under typical hovering and forward flight conditions. Both the interaction between the contralateral wings and the interaction between the body and wings are very weak, e.g. at hovering, changes in aerodynamic forces of a wing due to the present of the other wing are less than 3% and changes in aerodynamic forces of the wings due to presence of the body are less than 2%. The reason for this is as following. During each down- or up-stroke, a wing produces a vortex ring, which induces a relatively large jet-like flow inside the ring but very small flow outside the ring. The vortex rings of the left and right wings are on the two sides of the body. Thus one wing is outside vortex ring of the other wing and the body is outside the vortex rings of the left and right wings, resulting in the weak interactions.
文摘We give the moment expressions for the boson resonances X with spin-parity JXPXC=0++,1-+,1++ and 2++ posibly produced in the process J/ψ→ρX，X→b1(1235)π，b1→ωπ in terms of the generalized moment analysis method .The resonance with JXPXC=1-+ can e distingguished from other resonances by means of these moments exceptfor some rather special cases.The suggestion that the search for the hybrid with IG(JPC)=1-(1-+) can be performed in the decay channl J/ψ→ρωππat upgraded BEPC/BES is presented.
