Turbulent intensities distributions over a riblets surface

The experimental study on the characteristics of turbulent intensity distribution over the riblets surface and smooth surface was performed. The experimental installation and measurement method of using laser Doppler velocimeter were presented. The experimental results have indicated that maximum value of turbulent intensity is smaller, but its occurrence position is farther in comparison with results of smooth surface. The greater value of turbulent intensity exists in the region near the riblets surface, it means riblets surface enhances flow turbulence. For ratio of depth to thickness of boundary layer greater than or equal to 0.06, the distribution of turbulent intensity is exponential relation, otherwise it is linear relation.