http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Time-Resolved PIV Investigation on the Unsteadiness of a Low Reynolds Number Confined Impinging Jet
Kim, K. C.,Min, Y. U.,Oh, S. J.,An, N. H.,Seoudi, B.,Chun, H. H.,Lee, I. Ohmsha 2007 JOURNAL OF VISUALIZATION Vol.10 No.4
<P>The flow characteristics in a confined slot jet impinging on a flat plate were investigated in low Reynolds number regime by using time-resolved Particle Image Velocimetry technique. The jet Reynolds number was varied from 404 to 1026, where it is presumed that the transient regime exists. We found that the vortical structures in the shear layer are developed with increase of Reynolds number and that the jet becomes remains steady at the Reynolds number of 404. Vortical structures and their temporal evolution are verified and the results were compared with previous numerical studies. </P>
Visualization of the Inflow Ahead of a Rotating Propeller attached to a Container Ship Model
Paik, B. G.,Kim, G. D.,Lee, J. Y.,Lee, S. J. Ohmsha 2007 JOURNAL OF VISUALIZATION Vol.10 No.1
<P>The inflow ahead of a rotating propeller attached to a container ship model was visualized using a two-frame particle image velocimetry (PIV) technique. For illuminating the inflow region, a transparent window was installed at the stern of the ship model. Ensemble-averaged mean velocity fields were measured at four different blade phases under the design loading condition. The characteristics of the inflow in the upper plane above the propeller axis are quite different from those below the propeller axis. In the far upstream region above the propeller axis, most of the inflow comes from the hull wake and the axial velocity is very small. As the inflow moves toward the propeller plane, its axial velocity component increases rapidly. In addition, the variation of the inflow characteristics with respect to phase angle becomes apparent. The thick hull boundary layer and out-of-plane motion resulting from the propeller rotation produce a large turbulent kinetic energy around the tip of the propeller blade in the upper inflow region. The axial velocity distribution of the propeller inflow is asymmetric with respect to the vertical center axis, exhibiting different axial velocities on the port and starboard sides. </P>
Effect of the wind direction on the near wake structures of an Archimedes spiral wind turbine blade
Ji, H. S.,Qiang, L.,Beak, J. H.,Mieremet, R.,Kim, K. C. Ohmsha 2016 Journal of Visualization Vol. No.
<P>For urban usage of an Archimedes spiral horizontal axis wind turbine, the effect of wind direction was examined for the confront measurement planes from 0A degrees to 15A degrees. Aerodynamic characteristics in the near wake of wind turbine blade were investigated using the particle image velocimetry method. Ensemble and phase-averaged velocity fields were obtained in both front and lee sides of the blade with various angles of attack. The streamlines are parallel with the incoming flow for the range of attack angles; however, wake velocity is decreasing with increasing angle of attack. It has been found that the trajectory of tip vortices varies significantly in the front side plane compared to that of lee side plane when the angle of attack is higher than 10A degrees. Distance between two consecutive vortices in the front plane decreases monotonically with increasing attack angle, while that in the lee side shows an opporsite manner.</P>