Hi,

I've read people using terms like bulk & space-averaged velocity in many papers. however, i can't seem to find the definition for them. for e.g., in some convective boundary conditions, the c term in du/dt + c*du/dx = 0 refers to space-averaged exit velocity.

hope someone can enlighten me.

Thanks!

bulk: relative to different parts; space-averaged: as it means.

thanks. but what i need is the formula, say in a channel or duct flow. how can i calculate its value.