Sisevoolud looduslikus veekogus formeeruvad olukorras kus veesammas on ebaühtlaselt stratifitseeritud. Erineva tihedusega veeosad on looduslikes süsteemides eraldatud künnistega nagu uputatud liivakünkad estuaarides ja topograafilised madalikud hoovussängides, mis piiravad veeliikumise intensiivsust ja vee uuenemist estuaarides ja fjordides. Eksperimentaalsed uuringu METEO-FRANCE hüdromehaanika laboris keskenduvad stratifitseeritud voolu liikumise dünaamika eriküsimustele künnisega voolurennis.
Exchange flows occur when density differences are present in adjacent water bodies. These water bodies may be separated by a range of topographical features, including submerged sand bars at the mouths of estuaries and submarine sills within fjords. The presence of such natural topographic flow obstructions can have significant implications for the intrusion of saline marine waters into semi-enclosed estuarine impoundments or fjordic basins. Experimental investigations in the METEO-FRANCE fluid-mechanics laboratory will concentrate on special questions of stratified flow dynamics in silled channel.