In this paper,by applying theoretical method to the governing equations of compressible viscous flow,we derive the theoretical formula of the boundary dilatation flux(BDF)on a flexible wall,which generalizes the most ...In this paper,by applying theoretical method to the governing equations of compressible viscous flow,we derive the theoretical formula of the boundary dilatation flux(BDF)on a flexible wall,which generalizes the most recent work of Mao et al.(Acta Mechanica Sinica 38(2022)321583)for a stationary wall.Different boundary sources of dilatation are explicitly identified,revealing not only the boundary generation mechanisms of vortex sound and entropy sound,but also some additional sources due to the surface vorticity,surface angular velocity,surface acceleration and surface curvature.In particular,the generation mechanism of dilatation at boundary due to the coupled divergence terms is highlighted,namely,the product of the surface velocity divergence(▽_(■B)·U)and the vorticity-induced skin friction divergence(V_(■B)·τ_(ω)).The former is attributed to the surface flexibility while the latter characterizes the footprints of near-wall coherent structures.Therefore,by properly designing the surface velocity distribution,the dilatation generation at the boundary could be controlled for practical purpose in near-wall compressible viscous flows.展开更多
In this paper, we study the boundary dilatation of quasiconformal mappings in the unit disc. By using Strebel mapping by heights theory we show that a degenerating Hamilton sequence is determined by a quasisymmetric f...In this paper, we study the boundary dilatation of quasiconformal mappings in the unit disc. By using Strebel mapping by heights theory we show that a degenerating Hamilton sequence is determined by a quasisymmetric function.展开更多
The geometry of Teichmuller metric in an asymptotic Teichmuller space is studled in this article. First, a binary infinitesimal form of Teichmuller metric on AT（X） is proved. Then, the notion of angles between two g...The geometry of Teichmuller metric in an asymptotic Teichmuller space is studled in this article. First, a binary infinitesimal form of Teichmuller metric on AT（X） is proved. Then, the notion of angles between two geodesic curves in the asymptotic Teichmuller space AT（X） is introduced. The existence of such angles is proved and the explicit formula is obtained. As an application, a sufficient condition for non-uniqueness geodesics in AT（X） is obtained.展开更多
文摘In this paper,by applying theoretical method to the governing equations of compressible viscous flow,we derive the theoretical formula of the boundary dilatation flux(BDF)on a flexible wall,which generalizes the most recent work of Mao et al.(Acta Mechanica Sinica 38(2022)321583)for a stationary wall.Different boundary sources of dilatation are explicitly identified,revealing not only the boundary generation mechanisms of vortex sound and entropy sound,but also some additional sources due to the surface vorticity,surface angular velocity,surface acceleration and surface curvature.In particular,the generation mechanism of dilatation at boundary due to the coupled divergence terms is highlighted,namely,the product of the surface velocity divergence(▽_(■B)·U)and the vorticity-induced skin friction divergence(V_(■B)·τ_(ω)).The former is attributed to the surface flexibility while the latter characterizes the footprints of near-wall coherent structures.Therefore,by properly designing the surface velocity distribution,the dilatation generation at the boundary could be controlled for practical purpose in near-wall compressible viscous flows.
基金Supported by the National Natural Science Foundation of China （Grant Nos. 10171003 and 10231040） and the Doctoral Education Program Foundation of China
文摘In this paper, we study the boundary dilatation of quasiconformal mappings in the unit disc. By using Strebel mapping by heights theory we show that a degenerating Hamilton sequence is determined by a quasisymmetric function.
基金supported by National Natural Science Foundation of China(11371045,11301248)
文摘The geometry of Teichmuller metric in an asymptotic Teichmuller space is studled in this article. First, a binary infinitesimal form of Teichmuller metric on AT（X） is proved. Then, the notion of angles between two geodesic curves in the asymptotic Teichmuller space AT（X） is introduced. The existence of such angles is proved and the explicit formula is obtained. As an application, a sufficient condition for non-uniqueness geodesics in AT（X） is obtained.
