There has been a great deal of research on the driving force of aviation network.Moreover, the research methods and perspectives are also varied.This article mainly studies the driving force of aviation network,the in...There has been a great deal of research on the driving force of aviation network.Moreover, the research methods and perspectives are also varied.This article mainly studies the driving force of aviation network,the influencing factors of main driving force are analyzed.The driving force analysis of different airport and route is carried out respectively.The results can better reveal the connection mechanism of solid routes.Because the sample space of the hub airport and the trunk airport is too small,the conclusions are not sufficiently illustrative,therefore, this article studies only the branch airports.The conclusions are compared with the results of the comprehensive analysis,and we see if the conclusions are the same or similar.展开更多
This paper presents a random physical model of seismic ground motion field on a specific local engineering site.With this model,artificial ground motions which are consistent with realistic records at SMART-1 array on...This paper presents a random physical model of seismic ground motion field on a specific local engineering site.With this model,artificial ground motions which are consistent with realistic records at SMART-1 array on spatial correlation are synthesized.A two-scale modeling method of seismic random field is proposed.In large scale,the seismic ground motion field on bedrock surface is simplified to a two-dimensional spherical wave field based on the seismic point source and homogeneous isotropic media model.In small scale,the seismic ground motion field on the engineering site has a plane waveform.By introducing the physical models of seismic source,path and local site and considering the randomness of the basic physical parameters,the random model of seismic ground motion field is completed in a random functional form.This model is applied to simulation of the acceleration records at SMART-1 array by using the superposition method of wave group.展开更多
It is well known that the non-uniform tip geometry is a promising passive flow control technique in turbomachinery.However,detailed investigation of its effects on the unsteady flow field of turbomachinery is rare in ...It is well known that the non-uniform tip geometry is a promising passive flow control technique in turbomachinery.However,detailed investigation of its effects on the unsteady flow field of turbomachinery is rare in the existiug hteratures.This paper presents an experimental investigation of effects of suction side squealer tip configuration on both the steady and unsteady flow field of an isolated compressor rotor.The flow field at 10%chord downstream from the trailing edge was measured using a mini five-hole probe.Meanwhile,the unsteady flow field inside the passage was investigated using stereo particle image velocimetry(SPIV).The steady results show that the SSQ tip configuration exerts positive effect on the static pressure rise performance of this compressor,and the radial equilibrium at the rotor outlet is obviously rearranged.The SSQ tip configuration would create a stronger tip leakage vortex at the formation phase,and it experiences a faster dissipation process around the rear chord.Also,the splitting process of the tip leakage vortex is severer,which is the main cause of the relatively higher probability of the presence of the streamwise reverse flow.The quantitatively analysis of the tip leakage vortex indicates that the velocity loss inside the blockage region is direct response of the evolutionary procedure of the tip leakage vortex.It keeps increasing until the end of the splitting process.Although the blockage coefficient grows sustainably,the velocity loss will reduce once the turbulent mixing procedure is dominant.展开更多
文摘There has been a great deal of research on the driving force of aviation network.Moreover, the research methods and perspectives are also varied.This article mainly studies the driving force of aviation network,the influencing factors of main driving force are analyzed.The driving force analysis of different airport and route is carried out respectively.The results can better reveal the connection mechanism of solid routes.Because the sample space of the hub airport and the trunk airport is too small,the conclusions are not sufficiently illustrative,therefore, this article studies only the branch airports.The conclusions are compared with the results of the comprehensive analysis,and we see if the conclusions are the same or similar.
基金supported by the Funds for Creative Research Groups of China (Grant No. 50621062)
文摘This paper presents a random physical model of seismic ground motion field on a specific local engineering site.With this model,artificial ground motions which are consistent with realistic records at SMART-1 array on spatial correlation are synthesized.A two-scale modeling method of seismic random field is proposed.In large scale,the seismic ground motion field on bedrock surface is simplified to a two-dimensional spherical wave field based on the seismic point source and homogeneous isotropic media model.In small scale,the seismic ground motion field on the engineering site has a plane waveform.By introducing the physical models of seismic source,path and local site and considering the randomness of the basic physical parameters,the random model of seismic ground motion field is completed in a random functional form.This model is applied to simulation of the acceleration records at SMART-1 array by using the superposition method of wave group.
基金co-supported by the National Natural Science Foundation of China(Grant No.51161130525/No.51136003)the 111Project(No.B07009)
文摘It is well known that the non-uniform tip geometry is a promising passive flow control technique in turbomachinery.However,detailed investigation of its effects on the unsteady flow field of turbomachinery is rare in the existiug hteratures.This paper presents an experimental investigation of effects of suction side squealer tip configuration on both the steady and unsteady flow field of an isolated compressor rotor.The flow field at 10%chord downstream from the trailing edge was measured using a mini five-hole probe.Meanwhile,the unsteady flow field inside the passage was investigated using stereo particle image velocimetry(SPIV).The steady results show that the SSQ tip configuration exerts positive effect on the static pressure rise performance of this compressor,and the radial equilibrium at the rotor outlet is obviously rearranged.The SSQ tip configuration would create a stronger tip leakage vortex at the formation phase,and it experiences a faster dissipation process around the rear chord.Also,the splitting process of the tip leakage vortex is severer,which is the main cause of the relatively higher probability of the presence of the streamwise reverse flow.The quantitatively analysis of the tip leakage vortex indicates that the velocity loss inside the blockage region is direct response of the evolutionary procedure of the tip leakage vortex.It keeps increasing until the end of the splitting process.Although the blockage coefficient grows sustainably,the velocity loss will reduce once the turbulent mixing procedure is dominant.
