From a unified perspective, this review describes global skin friction diagnostics based on
surface flow visualizations. The foundations of the developed image-based methods are …

Vortical flows are flows with vortices as their skeleton structures. Vortices are seen
everywhere in our universe and on the earth: from spiral galaxies, atmospheric and oceanic …

High-resolution time-averaged skin-friction fields in wing–body junction flows are extracted
from luminescent oil-film visualization images taken at different viewing angles and positions …

A variational solution of the physics-based optical flow equation is studied for extraction of
high-resolution velocity fields from flow visualization images. The solution to preserve …

The feasibility of skin-friction field measurements using the global luminescent oil-film skin-
friction field estimation method was evaluated for a challenging case of a supercritical airfoil …

This paper develops the principle of global skin friction diagnostics based on temperature
sensitive paint (TSP) measurements in flows. The asymptotic form of the energy equation at …

The surface flow pattern over a conical boattail on an axisymmetric body was investigated
experimentally under low-speed and turbulent-boundary-layer conditions. Seven conical …

Skin-friction τ and surface-pressure p in a viscous flow constitute a pair of the intrinsically
coupled physical quantities denoted by the notation (τ, p), which determines the near-wall …

The effect of Reynolds number on flow behaviors and pressure drag around axisymmetric
conical boattails was experimentally investigated at low-speed conditions. Four conical …

Extraction of high-resolution skin-friction fields from surface flow visualization images as an
inverse problem is discussed from a unified perspective. The surface flow visualizations …