Flow-Induced Crystallization Tutorial

This first tutorial checks that the Crystal application runs and shows how the GO-polySTRAND theory responds to a simple synthetic data set. The files used here are theory-generated data, so the calculation is intended as a reproducible sanity check before working with experimental crystallization data.

Load Synthetic Data

  1. Start RepTate and create a new Flow Induced Crystallization Application logo.

  2. Open the three synthetic files in data/Crystal:

    • InitialTest_gdot0.05.shearxs

    • InitialTest_gdot0.1.shearxs

    • InitialTest_gdot0.2.shearxs

    These files use the .shearxs format handled by the Crystal application: each file stores gdot, T, and tstop parameters and the columns t, sigma_xy, Ndot, phi_X, and N.

  3. Use the plot tabs on the left of the application window to inspect the individual plots. Use the View selector near the upper-right corner of the application window to switch between stress, viscosity, nucleation rate, nucleation density, and crystal-fraction views.

Run GO-polySTRAND

  1. In the theory selector, choose GO-polySTRAND and create the theory einstein.

  2. Calculate the theory calculate once with the default settings to confirm that the model runs on the loaded files.

  3. For the synthetic data check, set both G_C and N_0 to 1e-3 and calculate again. The tutorial data were generated from theory output, and these values are the documented settings for reproducing the crystal-fraction and nucleation-density curves.

Things To Try

After the initial calculation, explore the model response by changing one setting at a time:

  • Change Gamma to adjust the sensitivity to shear.

  • Make small changes to epsilonB to adjust the quiescent crystallization barrier. In the original tutorial notes this is described as analogous to changing temperature.

  • Adjust tau0 to scale the nucleation rates.

  • Adjust G_C to change the crystal growth rate.

  • Use the theory’s modes menu to edit the number of modes, relaxation times, and mode fractions. The mode fractions should add up to 1.

  • Double-click a data set and edit file parameters such as gdot and tstop to see how the plotted quantities respond. The T parameter is stored by the .shearxs file type; the initial tutorial notes state that it has no effect in this synthetic check.

Steady Nucleation View

  1. Open the data files in data/Crystal/CoccorulloMacromolecules2008/Steady_Shear_Nucleation_Data.

  2. Reduce the application to one view if you want a compact plot, then select the Steady Nucleation view. This view gives one point per loaded file, using the flow rate from the file parameters on the x-axis and the final nucleation-rate value on the y-axis.

  3. Use View All to show the loaded files together.