Data set dense granular flow of elongated and flattened particles

Description

Series information

This dataset contains the results of numerical simulations stored in individual Python pickle (.pkl) files. Each file corresponds to a single simulation run and contains a Python dictionary with various physical and computational quantities measured or derived during the simulation. These quantities include time-dependent observables, diagnostic metrics, and simulation parameters, structured in a consistent format across files to facilitate post-processing and analysis.

• percent_aligned: the fraction of particles whose axis of symmetry makes an angle of less than pi/4 with the xz plane (prolate), xy plane (oblate)
• S2: nematic order parameter
• Omega_x, Omega_y, Omega_z: The components of the mean angular velocity vector (Ω) along the x, y, and z axes, respectively
• tke: translational component of the fluctuating kinetic energy
• rke: rotational component of the fluctuating kinetic energy
• omega_fluctuations: A 3-component array representing the root-mean-square (RMS) average fluctuation of the angular velocity components
• vx_fluctuations, vy_fluctuations, vz_fluctuations: RMS average fluctuation of the velocity components in the x, y, and z directions, respectively
• kinetic_stress: A 3×3 tensor representing the kinetic stress in the system
• measured_shear_rate: The observed or computed shear rate in the system
• c_r_values: The spatial separation distances (r) corresponding to the autocorrelation functions like c_delta_vy and c_delta_omega_z
• c_y_values: The spatial separation distances (y) corresponding to the correlation function c_density_y
• c_density_y: The spatial correlation of density along y (used to check smectic ordering)
• c_delta_vy: The spatial autocorrelation function of the velocity fluctuations in the y-direction
• c_delta_omega_z: The spatial autocorrelation function of the fluctuations in the z-component of angular velocity
• box_x_length, box_y_length, box_z_length: The physical dimensions of the simulation domain along the x, y, and z axes, respectively. Along y the dimension is averaged
• Z: The average coordination number — the mean number of contacts per particle in the system
• percent_sliding: The fraction of inter-particle contacts that are sliding (as opposed to sticking)
• stress_contacts: The contact stress tensor, derived from inter-particle contact forces and positions
• shear_stress_normal: The component of the contact stress tensor attributed to normal forces (perpendicular to contact surfaces)
• shear_stress_tangential: The tangential (or frictional) contribution to the shear stress tensor, resulting from forces parallel to contact surfaces
• fabric: The fabric tensor computed with the contact normals
• muI_dissipation: Energy dissipation estimated based on the μ(I) rheology framework
• thetax_mean, thetaz_mean: Circular mean angles (in radians) around the x axis in the xy-plane and the z axes in the xz, respectively
• shear_rate: The externally imposed or internally measured shear rate of the system. This scalar value quantifies the rate of deformation due to shear, playing a key role in flow characterization and rheology
• area_adjustment_ellipsoid: A 10 element array representing the surface area of the spehroids polar slices, from 0 to pi/2
• total_area: The total surface area of the average radius particles
• total_normal_dissipation: The total power dissipated through normal contact forces (perpendicular to contact surfaces)
• total_tangential_dissipation: The total power dissipated through tangential (frictional) contact forces
• pdf_thetax, pdf_thetaz: probability distribution of the angles whose means are thetax_mean and thetaz_mean respectively
• auto_corr_vel: The temporal autocorrelation function of particle velocity fluctuations in the y direction
• auto_corr_omega: The temporal autocorrelation function of angular velocity fluctuations in the z direction
• strain: A uniformly spaced array representing the accumulated shear strain in the system, used to compute the temporal autocorrelations
• inertialNumber: The dimensionless inertial number (I) measured troughtout the simulation
• phi: The solid volume fraction in the system
• press: The average isotropic pressure within the system, from the trace of the stress tensor
• p_yy: The component of stress tensor acting along the y-axis (normal stress in y direction)
• p_xy: The shear stress component acting in the plane defined by x and y directions
• Nx_diff, Nz_diff: First and second normal stress differences resepctively
• Dyy, Dzz: Diffusion coefficients along the y and z directions, respectively
• contacts_hist_global_normal, contacts_hist_global_tangential: Histogram contact forces measured in the normal and tangential direction, respectively
• power_dissipation_normal, power_dissipation_tangential: array of normal and tangential power dissipation accumulated on a single particle at constant polar angle spacing on the surface
• contacts_hist_cont_point_local / bin_counts_power: density of contacts per spheorid surface slice

Note: All the following quantities are measured at discrete, equally spaced slices along the y-axis.

• Ncount_avg & Ncount_std_dev: Average number of particles counted and its std
• vx_avg & vx_std_dev: Mean velocity component in the x-direction and its std
• vy_avg & vy_std_dev: Mean velocity component in the y-direction and its std
• vz_avg & vz_std_dev: Mean velocity component in the z-direction and its std
• c_omegaz_avg & c_omegaz_std_dev: Average angular velocity about the z-axis and its std
• density_mass_avg & density_mass_std_dev: Average local mass density and its std
• v_pxx_loc_avg & v_pxx_loc_std_dev: Average normal stress in the x-direction and its std
• v_pyy_loc_avg & v_pyy_loc_std_dev: Average normal stress in the y-direction and its std
• v_pzz_loc_avg & v_pzz_loc_std_dev: Average normal stress in the z-direction and its std
• v_pxy_loc_avg & v_pxy_loc_std_dev: Average shear stress in the xy-plane and its std