Velocitymap

Velocitymap is a representation of spatially distributed velocity data that maps speed and direction of motion across a region. It is used to visualize flow fields in engineering, physics, and earth sciences. A velocitymap can be two- or three-dimensional, typically rendered with color for speed and with vectors or streamlines for direction.

Velocitymaps are derived from measured or computed velocity fields. Experimental sources include particle image velocimetry (PIV), particle tracking velocimetry (PTV), and Doppler techniques, while numerical sources come from computational fluid dynamics (CFD). Data are interpolated onto a grid and may be filtered to reduce noise while preserving gradients.

Applications span fluid dynamics, aerodynamics, meteorology, oceanography, biomechanics, and crowd or traffic flow. They aid in diagnosing flow features such as separation and turbulence, assessing heat transfer, optimizing sensor placement, and modeling pollutant dispersion. In biology and medicine, velocitymaps enable analysis of blood flow and transport where velocity data are available.

Limitations include measurement noise, limited spatial and temporal resolution, and projection or interpolation biases. Three-dimensional velocitymaps can be hard to interpret and may require supplementary fields like vorticity. Visualization choices, such as color scales and glyphs, influence perception and should follow standard practices and validation.

Related concepts include vector field visualization, flow visualization techniques, PIV, CFD, and velocity fields.