DamköhlerZahl
The Damköhlerzahl, often abbreviated as Da, is a dimensionless number used in chemical engineering and reaction engineering to compare the relative timescales of chemical reactions and transport processes such as flow or diffusion. Named after the German chemist Gerhard Damköhler, the Damköhlerzahl provides insight into whether a reaction is limited by chemical kinetics or by mass transfer.
The Damköhlerzahl is typically defined as the ratio of the characteristic time for a flow or transport
In a simple form for homogeneous reactions, Da can be calculated as the product of the reaction
The value of Damköhler number indicates the dominant process: a low Da (less than 1) suggests that
Understanding the Damköhler number helps engineers optimize reactor design, control reaction conditions, and improve efficiency by