viscosity data fitting

viscosity data fitting

This tool allows you to fit measured viscosity data to a certain viscosity model.
Cross-WLF $$\eta = \frac{\eta_0}{1+(\frac{\eta_0 \cdot \dot{\gamma}}{\tau^{\star}})^{1-n}}$$ $$\eta_0 = D_1 exp(- \frac{A_1 (T-T^{\star})}{A_2 +(T-T^{\star})})$$ $$A_2 = A_3 + D_3 \cdot p$$ $$T_\star = D_2+D_3 \cdot p$$
  • `\eta` .. melt viscosity
  • `\eta_0` .. zero viscosity
  • `\dot{\gamma}` .. shear rate
  • `\tau^{\star}` .. critical stress at transition to shear thinning
  • `n` .. high shear exponent
  • `T` .. temperature
  • `T_\star` .. solidification temperature
  • `p` .. pressure
  • `D_1,A_1,A_3,D_3` .. fitting coefficients
Carreau-WLF $$\eta = \frac{P_1 a_T}{(1+a_T P_2 \dot{\gamma})^{P_3}}$$ $$log(a_T) = \frac{C_1 \cdot (T_0-T_s)}{C_2+(T_0-T_s)}-\frac{C_1 \cdot (T-T_s)}{C_2+(T-T_s)}$$
  • `P_1` .. zero viscosity [Pas]
  • `P_2` .. transition rate [s]
  • `P_3` .. Exponent
  • `T_s \approx T_s+50 ^\circ C`
  • `C_1=8.86`
  • `C_2 = 101.6 ^\circ C`

Choose your viscosity model:



Input your data here: