The effects induced by the presence of incoming wakes on the boundary layer developing over a high-lift low-pressure turbine profile have been investigated in a linear cascade at mid-span.The tested Reynolds number is...The effects induced by the presence of incoming wakes on the boundary layer developing over a high-lift low-pressure turbine profile have been investigated in a linear cascade at mid-span.The tested Reynolds number is 70000,typical of the cruise operating condition.The results of the investigations performed under steady and unsteady inflow conditions are analyzed.The unsteady investigations have been performed at the reduced frequency of f+=0.62,representative of the real engine operating condition.Profile aerodynamic loadings as well as boundary layer velocity profiles have been measured to survey the separation and transition processes.Spectral analysis has been also performed to better understand the phenomena associated with the transition process under steady inflow.For the unsteady case,a phase-locked ensemble averaging technique has been employed to reconstruct the time-resolved boundary layer velocity distributions from the hot-wire instantaneous signal output.The ensemble-averaging technique allowed a detailed analysis of the effects induced by incoming wakes-boundary layer interaction in separation suppression.Time-resolved results are presented in terms of mean velocity and unresolved unsteadiness time-space plots.展开更多
The paper deals with experimental and numerical results of investigation into supersonic and transonic flow past a two-dimensional model ejector. Results of optical measurements show a flow structure and flow paramete...The paper deals with experimental and numerical results of investigation into supersonic and transonic flow past a two-dimensional model ejector. Results of optical measurements show a flow structure and flow parameter development in the entrance part of the mixing chamber of the ejector. Numerical results are obtained by means of both the straight solution of shock waves in supersonic flow field using classical relations of parameters of shock waves and the Fluent 6 program. Results of numerical solutions are compared with experimental pictures of flow fields. Flow structure development in the mixing chamber is analysed in detail.展开更多
Seed dispersal is an important moment in the life cycle of a plant species. In Arabidopsis thaliana, it is dependent on transcription factor INDEHISCENT （IND）-mediated specification of a separation layer in the dehi...Seed dispersal is an important moment in the life cycle of a plant species. In Arabidopsis thaliana, it is dependent on transcription factor INDEHISCENT （IND）-mediated specification of a separation layer in the dehiscence zone found in the margin between the valves （carpel walls） and the central replum of the developing fruit. It was proposed that IND specifies the separation layer by inducing a local auxin minimum at late stages of fruit development. Here we show that morphological differences between the ind mutant and wild-type fruit already arise at early stages of fruit development, coinciding with strong IND expression in the valve margin. We show that IND-reduced PIN-FORMED3 （PIN3） auxin efflux carrier abundance leads to an increased auxin response in the valve margin during early fruit develop- ment, and that the concomitant cell divisions that form the dehiscence zone are lacking in ind mutant fruit. Moreover, IND promoter-driven ectopic expression of the AGC kinases PINOID （PID） and WAG2 induced indehiscence by expelling auxin from the valve margin at stages 14-16 of fruit development through increased PIN3 abundance. Our results show that IND, besides its role at late stages of Arabi- dopsis fruit development, functions at early stages to facilitate the auxin-triggered cell divisions that form the dehiscence zone.展开更多
文摘The effects induced by the presence of incoming wakes on the boundary layer developing over a high-lift low-pressure turbine profile have been investigated in a linear cascade at mid-span.The tested Reynolds number is 70000,typical of the cruise operating condition.The results of the investigations performed under steady and unsteady inflow conditions are analyzed.The unsteady investigations have been performed at the reduced frequency of f+=0.62,representative of the real engine operating condition.Profile aerodynamic loadings as well as boundary layer velocity profiles have been measured to survey the separation and transition processes.Spectral analysis has been also performed to better understand the phenomena associated with the transition process under steady inflow.For the unsteady case,a phase-locked ensemble averaging technique has been employed to reconstruct the time-resolved boundary layer velocity distributions from the hot-wire instantaneous signal output.The ensemble-averaging technique allowed a detailed analysis of the effects induced by incoming wakes-boundary layer interaction in separation suppression.Time-resolved results are presented in terms of mean velocity and unresolved unsteadiness time-space plots.
文摘The paper deals with experimental and numerical results of investigation into supersonic and transonic flow past a two-dimensional model ejector. Results of optical measurements show a flow structure and flow parameter development in the entrance part of the mixing chamber of the ejector. Numerical results are obtained by means of both the straight solution of shock waves in supersonic flow field using classical relations of parameters of shock waves and the Fluent 6 program. Results of numerical solutions are compared with experimental pictures of flow fields. Flow structure development in the mixing chamber is analysed in detail.
文摘Seed dispersal is an important moment in the life cycle of a plant species. In Arabidopsis thaliana, it is dependent on transcription factor INDEHISCENT （IND）-mediated specification of a separation layer in the dehiscence zone found in the margin between the valves （carpel walls） and the central replum of the developing fruit. It was proposed that IND specifies the separation layer by inducing a local auxin minimum at late stages of fruit development. Here we show that morphological differences between the ind mutant and wild-type fruit already arise at early stages of fruit development, coinciding with strong IND expression in the valve margin. We show that IND-reduced PIN-FORMED3 （PIN3） auxin efflux carrier abundance leads to an increased auxin response in the valve margin during early fruit develop- ment, and that the concomitant cell divisions that form the dehiscence zone are lacking in ind mutant fruit. Moreover, IND promoter-driven ectopic expression of the AGC kinases PINOID （PID） and WAG2 induced indehiscence by expelling auxin from the valve margin at stages 14-16 of fruit development through increased PIN3 abundance. Our results show that IND, besides its role at late stages of Arabi- dopsis fruit development, functions at early stages to facilitate the auxin-triggered cell divisions that form the dehiscence zone.
