Energy Input per Unit Mass (E)

Calculation Explanation

This calculator estimates the energy input per unit mass of fluid (E) for bubble column and airlift bioreactors, based on gas sparging.

Bubble Columns:
The energy input is estimated as:
E = g ⋅ U_G
Where:

• E: Energy input per unit mass (W/kg or m²/s³).
• g: Acceleration due to gravity (assumed 9.81 m/s²).
• U_G: Superficial gas velocity (m/s).

Airlift Bioreactors:
The energy input accounts for the geometry of the riser and downcomer:
E = ( g ⋅ U_Gr ) / ( 1 + (A_d / A_r) )
Where:

• E: Energy input per unit mass (W/kg or m²/s³).
• g: Acceleration due to gravity (assumed 9.81 m/s²).
• U_Gr: Superficial gas velocity in the riser section (m/s).
• A_d: Cross-sectional area of the downcomer (m²).
• A_r: Cross-sectional area of the riser (m²).

Ensure consistent SI units (m, s) for inputs.