https://doi.org/10.1351/goldbook.D01740
The ratio of the ingoing @V06642@ (\(\frac{\text{d}V}{\text{d}t}\)) and the culture volume (\(V\)). In continuous @F02337@, a measure of a rate at which the existing medium is replaced with fresh medium, \(D\) is the reciprocal of the hydraulic retention time (\(\mathrm{HRT}\)).