INTENSIFICATION OF THE DETACHED FLOW IN A SINGLE ROW OF INCLINED OVAL TRENCH DIMPLES ON THE WALL OF A NARROW CHANNEL

An analysis of the intensifi cation of a steady-state detached turbulent air fl ow with Re = 104 in a row of oval trench dimples, positioned on the wall of a narrow channel and oriented at an agile of 45o to the incident fl ow, is given. It is shown that the anomalously high velocities of the reverse and secondary fl ows at the entrance of such a dimple (of the order of the mean mass velocity of the fl ow in the channel), as well as the negative friction in this part of the dimple that exceeds in absolute value the friction on the plane wall of the channel by almost fi ve times, are due to the difference between the total pressure in the near zones of stagnation of the air fl ow at the windward slope of the dimple and the negative pressure at the site of generation of a whirlwind-like vortex structure in the dimple.
   
Author:  S. A. Isaev, A. I. Leont′ev, D. V. Nikushchenko A. G. Sudakov, and A. E. Usachov
Keywords:  inclined oval trench dimples, narrow channel, intensifi cation, detached fl ow
Page:  151