Direct measurement of vorticity and its transport in the surface layer over a paddy field

Wind tunnel modeling of atmospheric emissions from agricultural burning: influence of operating configuration on flame structure and particle emission factor for a spreading-type fire

“…Consequently, the relevant large length scales would be of the same order in both field and tunnel flows, i.e., a flame height of several hundred millimeters for the opposed flow condition over a straw layer. The estimated turbulence intensity in the atmospheric boundary layer is approximately 15 % of the local mean velocity at heights from to 30 m above the ground ( 19), and just above plant canopies measurements range from approximately 30% to 120% (20)(21)(22)(23). The lower values are typical of the turbulence intensities in the tunnel at the height of the fire.…”

Spectra of velocity circulation in the surface layer of the atmosphere

“…In addition, it seems reasonable to think that the flux of vorticity in the atmospheric surface layer is caused mainly by large-scale coherent structures. Hence, one-point combination of the velocity circulation sensor with those of the velocity component and temperature allows the low-frequency part of corresponding cospectra (Ohtou et al, 1983) to be obtained.…”

“…Measurements of velocity circulation have been made to obtain information on the vorticity, Q = curlv (Bovsheverov et al, 1971;Ohtou et al, 1983;Elefterios et al, 1983). The method of measurement was based on Stokes's theorem, relating vorticity flux to velocity circulation.…”