Geometry Calculator

Compound

Sets C_s, D, and ρ below from literature values. Pick "Custom" to set them yourself.

Geometry

Select a geometry above to set its dimensions.

Sphere

Radius, r1.70 mm

Cube

Edge length, s2.70 mm

Cylinder

Radius, r1.50 mm

Height, h3.00 mm

Hemisphere

Radius, r2.10 mm

Solid & Medium

Solid density, ρ1.20 g/cm³

Saturation solubility, C_s5.0 mg/mL

Initial bulk conc., C₀0.0 mg/mL

Dissolution medium, V_soln500 mL

Boundary Layer & Hydrodynamics

Diffusion coefficient, D1.0 × 10⁻⁵ cm²/s

Sherwood correlation (Ranz–Marshall)

Boundary layer thickness, h10 µm

Flow velocity, U5.0 cm/s

Kinematic viscosity, ν0.0100 cm²/s

Validated against real rotating-disk data (Kaunisto et al., Pharm Dev Technol 2009, 14:400–408): this correlation overpredicted measured dissolution rates by 3–5× across 30–100 rpm for benzoic acid and aspirin. It gets the direction of hydrodynamic effects right, not the absolute rate. For a real number, calibrate h from a known mass-transfer coefficient instead of relying on this toggle.

Simulation

Duration60 min

Show Hixson–Crowell overlay

Y-axis

Dissolution profile by geometry