This paper introduces an image processing technique into seismic data processing as a noise attenuation technology. The image separation of the seismic profile is obtained by using grating operators based on different...This paper introduces an image processing technique into seismic data processing as a noise attenuation technology. The image separation of the seismic profile is obtained by using grating operators based on different time dips and a set of relative single dip profiles is obtained. A high signal to noise ratio profile can be obtained during reconstruction by statistical weighting. With further processing analysis and geological study, a high signal to noise profile that can meet geological requirements can be produced. The real data examples show that the signal to noise ratio of the profile is greatly improved, the resolution of the profile is maintained, and the fault terminations are much clearer after using the image processing method.展开更多
Particle image velocimetry was applied to the study of the statistical properties and the coherent structures of a fiat plate turbulent boundary layer at Mach 3. The nanoparticles with a good flow-following capability...Particle image velocimetry was applied to the study of the statistical properties and the coherent structures of a fiat plate turbulent boundary layer at Mach 3. The nanoparticles with a good flow-following capability in supersonic flows were adopted as the tracer particles in the present experiments. The results show that the Van Driest transformed mean velocity profile satisfies the incompressible scalings and reveals a log-law region that extends to yld=0.4, which is further away from the wall than that in incompressible boundary layers. The Reynolds stress profiles exhibit a plateau-like region in the log-law region. The hairpin vortices in the streamwise-wall-normal plane are identified using different velocity decompositions, which are similar to the results of the flow visualization via NPLS technique. And multiple hairpin vortices are found moving at nearly the same velocity in different regions of the boundary layer. In the streamwise-spanwise plane, elongated streaky structures are observed in the log-law region, and disappear in the outer region of the boundary layer, which is contrary to the flow visualization results.展开更多
基金This research is sponsored by China National Natural Science Foundation （No. 40574050, No. 40521002） and CNPC Innovation Fund （04E702）.
文摘This paper introduces an image processing technique into seismic data processing as a noise attenuation technology. The image separation of the seismic profile is obtained by using grating operators based on different time dips and a set of relative single dip profiles is obtained. A high signal to noise ratio profile can be obtained during reconstruction by statistical weighting. With further processing analysis and geological study, a high signal to noise profile that can meet geological requirements can be produced. The real data examples show that the signal to noise ratio of the profile is greatly improved, the resolution of the profile is maintained, and the fault terminations are much clearer after using the image processing method.
基金supported by the National Basic Research Program of China (Grant No. 2009CB724100)
文摘Particle image velocimetry was applied to the study of the statistical properties and the coherent structures of a fiat plate turbulent boundary layer at Mach 3. The nanoparticles with a good flow-following capability in supersonic flows were adopted as the tracer particles in the present experiments. The results show that the Van Driest transformed mean velocity profile satisfies the incompressible scalings and reveals a log-law region that extends to yld=0.4, which is further away from the wall than that in incompressible boundary layers. The Reynolds stress profiles exhibit a plateau-like region in the log-law region. The hairpin vortices in the streamwise-wall-normal plane are identified using different velocity decompositions, which are similar to the results of the flow visualization via NPLS technique. And multiple hairpin vortices are found moving at nearly the same velocity in different regions of the boundary layer. In the streamwise-spanwise plane, elongated streaky structures are observed in the log-law region, and disappear in the outer region of the boundary layer, which is contrary to the flow visualization results.
