The Flow Of Gases In Furnaces

FORMULA FOR THE INVERTED WEIR 159
A being a coefficient determined experimentally and depending
upon the depth of the gaseous stream, h, the thickness of the crest
of the weir in the direction of flow, Ey the velocity with which the
gases arrive at the weir or sill, the temperature and specific weight
of the gas composing the stream, and the roughness of the walls
at the sides and top of the flowing stream.