Experimental Investigation into the Drag Performance of Chevron-Shaped Protrusions in Wall-Bounded Turbulence

Chevron-shaped protrusions have been proposed in the literature for turbulent skin friction reduction. However, there is no consensus on the performance of this passive flow control technique; both an increase and a decrease in drag have been observed in previous studies. There is also no experimental evidence to support the working mechanism...

Experimental and numerical investigation into the drag performance of dimpled surfaces in a turbulent boundary layer

Although several previous studies have reported a potential drag-reducing effect of dimpled surfaces in turbulent boundary layers, there is a lack of replicability across experiments performed by different research groups. To contribute to the dialogue, we scrutinize one of the most studied dimple geometries reported in the literature, which...

Reducing turbulent convective heat transfer with streamwise plasma vortex generators

The effect of streamwise plasma vortex generators on the convective heat transfer of a turbulent boundary layer is experimentally investigated. A Dielectric Barrier Discharge (DBD) plasma-actuator array is employed to promote pairs of counter-rotating, streamwise-aligned vortices embedded in a well-behaved turbulent boundary layer over a flat...

Effect of drag reducing riblet surface on coherent structure in turbulent boundary layer

The characteristics of turbulent boundary layer over streamwise aligned drag reducing riblet surface under zero-pressure gradient are investigated using particle image velocimetry. The formation and distribution of large-scale coherent structures and their effect on momentum partition are analyzed using two-point correlation and probability...

Universal characterization of wall turbulence for fluids with strong property variations

Wall-bounded turbulence involving mixing of scalars, such as temperature or concentration fields, play an important role in many engineering applications. In applications with large temperature or concentration differences, the variation of scalar dependent thermos physical properties can be strong. In such cases the strong coupling between...

A program for the computation of a compressible turbulent boundary layer under infinite swept wing conditions.

A method is presented to compute the 3D compressible turbulent boundary layer on an adiabatic wall under infinite swept wing conditions. The mathematical model of turbulence is based on a generalisation of Bradshaw's 2D shear stress equation. This results in a system of 5 equations valid along 5 distinct characteristics. A brief discussion is...