CORRELATION OF LOCAL FLOW ACCELERATION IN A NARROW CHANNEL AND ANOMALOUS INTENSIFICATION OF SEPARATED LAMINAR FLOW IN TWO-ROW GROOVES ON ITS WALL

The phenomenon of local acceleration of laminar fl ow at the experimental stand of the Kazan Scientifi c Center of the Russian Academy of Sciences was substantiated by comparing the numerical predictions obtained on a digital analog with the profi les of the longitudinal velocity component measured at Re = 1000 at three points of the 22nd inclined groove in a narrow channel with 26 two-row grooves arranged in the form of \ / on the wall. A connection has been established between the local acceleration of the fl ow in the channel core and anomalous intensifi cation of separated laminar fl ow in two-row grooves on increase in the Reynolds number from 1000 to 2500. It has been found that at Re = 2500 for grooves remote from the entrance in the longitudinal section of the channel passing through the centers of the connecting sections of input spherical segments and trench parts, the negative relative friction reaches minimum values of the order of –9 and is combined with the achievement of maximum velocity values in the shear layers above the grooves (at a height of y = 0.005) of the order of 1.4.
The phenomenon of local acceleration of laminar fl ow at the experimental stand of the Kazan Scientifi c Center of the Russian Academy of Sciences was substantiated by comparing the numerical predictions obtained on a digital analog with the profi les of the longitudinal velocity component measured at Re = 1000 at three points of the 22nd inclined groove in a narrow channel with 26 two-row grooves arranged in the form of \ / on the wall. A connection has been established between the local acceleration of the fl ow in the channel core and anomalous intensifi cation of separated laminar fl ow in two-row grooves on increase in the Reynolds number from 1000 to 2500. It has been found that at Re = 2500 for grooves remote from the entrance in the longitudinal section of the channel passing through the centers of the connecting sections of input spherical segments and trench parts, the negative relative friction reaches minimum values of the order of –9 and is combined with the achievement of maximum velocity values in the shear layers above the grooves (at a height of y = 0.005) of the order of 1.4.
Author:  S. A. Isaev, D. V. Nikushchenko, N. I. Mikheev, N. S. Dushin, A. A. Klyus, E. A. Osiyuk
Keywords:  separated fl ow, narrow channel, inclined groove, intensifi cation, numerical simulation, experiment
Page:  1257