On Reynolds number dependence of micro-ramp-induced transition

The variation of transitional flow features past a micro-ramp is investigated when the Reynolds number is decreased approaching the critical regime. Experiments are conducted in the incompressible flow spanning from supercritical to subcritical roughness-height-based Reynolds number ( , 730, 460 and 320) with tomographic particle image...

Infrared thermography investigation of transitional flow over isolated roughness at high speed

The transitional flow features over and downstream of isolated roughness elements in hypersonic flow are investigated by means of infrared thermography. The local heat flux distribution in the wake of the roughness element reveals the footprint of multiple streamwise counter-rotating vortex pairs. The formation of a turbulent wedge with the...

On Reynolds Number Dependence of Micro-ramp-Induced Transition

The transitional flow features past a micro-ramp are investigated in the incompressible flow regime at critical and supercritical roughness-height based Reynolds number (Reh). Tomographic PIV is adopted as the diagnostic technique to identify the instantaneous three-dimensional flow behaviour in the domain of 73 ramp height streamwise. The...

Geometry effect of isolated roughness on boundary layer transition investigated by tomographic PIV

Boundary layer transition over isolated roughness elements is investigated in the incompressible flow regime using tomographic PIV. Four different geometries (cylinder, square, hemisphere and micro-ramp) are considered maintaining constant height and span of the element. The main target is to compare the different flow topologies and study the...

Roughness Induced Boundary Layer Transition in Incompressible Flow

The fluid dynamics process leading to laminar-turbulent transition behind an isolated roughness element is investigated in the incompressible regime using particle image velocimetry. The study covers the effect of roughness size and geometry on the promotion of transition. The measurement domain covers a large streamwise range from the near wake...

Geometry effect of isolated roughness on boundary layer transition investigated by tomographic PIV

Transitional flow over isolated roughness elements is investigated in the incompressible flow regime using Tomographic PIV. Three different geometries are considered (micro-ramp, cylinder and square) with same height and span. Their effect on accelerating boundary layer transition is compared and discussed. The measurement domain encompasses the...