r m Radial distance to rotation axis in centrifuge $\overline{r}$ m Average radial distance in centrifuge r0 m Radial reference distance in centrifuge at z = 0 (base of sediment or top of cream) RGF - Relative Gravity Force = acceleration factor in centrifuge with respect to free fall (RGF = 1 in earth’s gravity) $\text{RGF}=|g/{g}_{grav}|$ s - Structured fabric phase containing dispersed solids and emulsion droplets t s Time T - Dimensionless time $T=t/\tau$ v m/s Speed $U\left(\varphi \right)$ - Dimensionless fluid flow speed $U\left(\varphi \right)=-\delta {\varphi }^{2}/\left(1-\varphi \right)$ V m3/(m2s) The volume per unit time per unit lateral area WE - whole egg x m Spatial coordinate, often horizontal z m Spatial coordinate, often vertical. Increases with height Z m Horizontal distance from bottom vessel in centrifuge $Z={r}_{0}-r$ δ - Dimensionless number for relative importance of gravity over elasticity in earth’s gravity (RGF = 1) and in centrifuge $\delta =-\text{RGF}\left(\Delta \rho {g}_{grav}H/{\epsilon }_{0}\right){\left(1-{\varphi }_{0}\right)}^{3}/{\varphi }_{0}^{4}$ ε N/m2 Elasticity $\varphi$ - Porosity, here fractional volume available for fluid $\varphi ={\varphi }_{w}$ ${\varphi }_{s}$ - Volume fraction dispersed phase (solids, air, oil, and structurant) ${\varphi }_{w}$ - Porosity = local fractional volume available for fluid ${\varphi }_{w}+{\varphi }_{s}=1$ ${\varphi }_{0}$ - Initial porosity, initial volume fraction available for fluid μ Pas Viscosity of a fluid, μw for aqueous phase p - pi p = 3.141592654 P - Dimensionless Pi number ρ kg/m3 Density, mass per unit volume; ρs for dispersed, ρw for fluid τ s Relaxation time $\tau =\left(\left(1-{\varphi }_{0}\right)/{\varphi }_{0}\right)2\mu {H}^{2}/\left({k}_{0}{\epsilon }_{0}\right)$ ω rad/s Cyclic frequency $\omega =2\text{π}f$ ξ - Dimensionless vertical distance from bottom of vessel $\xi =z/H$ Θ - Dimensionless height of depleted zone $\Theta =\Omega /H$ Ω m Height of depleted zone Δρ kg/m3 Average density difference between dispersed and fluid phase, positive in sedimentation $\Delta \rho ={\rho }_{s}-{\rho }_{w}$