tfix transient porosity computations - cngf-pf - continuum model for granular flows with pore-pressure dynamics (renamed from 1d_fd_simple_shear)
(HTM) git clone git://src.adamsgaard.dk/cngf-pf
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---
(DIR) commit e31d3345807d0cb55f417a1955a601fa4ee8b14f
(DIR) parent f36482758fdcf502bc8934b5a14aa13604d01d7b
(HTM) Author: Anders Damsgaard <anders@adamsgaard.dk>
Date: Wed, 18 Nov 2020 10:28:15 +0100
fix transient porosity computations
Diffstat:
M cngf-pf.1 | 4 ++--
M cngf-pf.c | 3 +--
M simulation.c | 105 +++++++++++++++++++-------------
M simulation.h | 22 ++++------------------
4 files changed, 70 insertions(+), 64 deletions(-)
---
(DIR) diff --git a/cngf-pf.1 b/cngf-pf.1
t@@ -108,8 +108,8 @@ Fluid dynamic viscosity [Pa*s] (1.787e-3).
Only relevant with fluid dynamics enabled
.Fl ( F ) .
.It Fl K Ar dilatancy-constant
-Factor relating dilatancy and shear stress [TODO] (default 1.0).
-Only relevant with transient granular dynamics enabled
+Factor relating dilatancy angle to the volume fraction [-] (default
+4.09). Only relevant with transient granular dynamics enabled
.Fl ( T ) .
.It Fl k Ar fluid-permeability
Darcian intrinsic permeability of granular material [m^2] (default
(DIR) diff --git a/cngf-pf.c b/cngf-pf.c
t@@ -137,7 +137,7 @@ main(int argc, char *argv[])
sim.mu_f = atof(EARGF(usage()));
break;
case 'K':
- sim.dilatancy_angle = atof(EARGF(usage()));
+ sim.dilatancy_constant = atof(EARGF(usage()));
break;
case 'k':
new_k = atof(EARGF(usage()));
t@@ -280,7 +280,6 @@ main(int argc, char *argv[])
write_output_file(&sim, normalize);
filetimeclock = 0.0;
}
- sim.t += sim.dt;
filetimeclock += sim.dt;
iter++;
(DIR) diff --git a/simulation.c b/simulation.c
t@@ -58,7 +58,7 @@ init_sim(struct simulation *sim)
sim->transient = 0;
sim->phi_min = 0.20;
sim->phi_max = 0.55;
- sim->dilatancy_angle = 1.0;
+ sim->dilatancy_constant = 4.09; /* Pailha & Pouliquen 2009 */
/* Iverson et al 1997, 1998: Storglaciaren till */
/* sim->mu_s = tan(DEG2RAD(26.3)); */
t@@ -141,26 +141,27 @@ prepare_arrays(struct simulation *sim)
free(sim->phi);
free(sim->k);
- sim->z = linspace(sim->origo_z, /* spatial coordinates */
+ sim->z = linspace(sim->origo_z, /* spatial coordinates */
sim->origo_z + sim->L_z,
sim->nz);
- sim->dz = sim->z[1] - sim->z[0]; /* cell spacing */
- sim->mu = zeros(sim->nz); /* stress ratio */
- sim->mu_c = zeros(sim->nz); /* critical-state stress ratio */
- sim->sigma_n_eff = zeros(sim->nz); /* effective normal stress */
- sim->sigma_n = zeros(sim->nz); /* normal stess */
+ sim->dz = sim->z[1] - sim->z[0]; /* cell spacing */
+ sim->mu = zeros(sim->nz); /* stress ratio */
+ sim->mu_c = zeros(sim->nz); /* critical-state stress ratio */
+ sim->sigma_n_eff = zeros(sim->nz); /* effective normal stress */
+ sim->sigma_n = zeros(sim->nz); /* normal stess */
sim->p_f_ghost = zeros(sim->nz + 2); /* fluid pressure with ghost nodes */
- sim->phi = zeros(sim->nz); /* porosity */
- sim->phi_c = zeros(sim->nz); /* critical-state porosity */
- sim->phi_dot = zeros(sim->nz); /* rate of porosity change */
- sim->k = zeros(sim->nz);/* permeability */
- sim->xi = zeros(sim->nz); /* cooperativity length */
- sim->gamma_dot_p = zeros(sim->nz); /* shear velocity */
- sim->v_x = zeros(sim->nz); /* shear velocity */
- sim->g_local = zeros(sim->nz); /* local fluidity */
- sim->g_ghost = zeros(sim->nz + 2); /* fluidity with ghost nodes */
- sim->I = zeros(sim->nz);/* inertia number */
- sim->tan_psi = zeros(sim->nz); /* tan(dilatancy_angle) */
+ sim->p_f_dot = zeros(sim->nz); /* fluid pressure change */
+ sim->phi = zeros(sim->nz); /* porosity */
+ sim->phi_c = zeros(sim->nz); /* critical-state porosity */
+ sim->phi_dot = zeros(sim->nz); /* rate of porosity change */
+ sim->k = zeros(sim->nz); /* permeability */
+ sim->xi = zeros(sim->nz); /* cooperativity length */
+ sim->gamma_dot_p = zeros(sim->nz); /* shear velocity */
+ sim->v_x = zeros(sim->nz); /* shear velocity */
+ sim->g_local = zeros(sim->nz); /* local fluidity */
+ sim->g_ghost = zeros(sim->nz + 2); /* fluidity with ghost nodes */
+ sim->I = zeros(sim->nz); /* inertia number */
+ sim->tan_psi = zeros(sim->nz); /* tan(dilatancy_angle) */
}
void
t@@ -172,6 +173,7 @@ free_arrays(struct simulation *sim)
free(sim->sigma_n_eff);
free(sim->sigma_n);
free(sim->p_f_ghost);
+ free(sim->p_f_dot);
free(sim->k);
free(sim->phi);
free(sim->phi_c);
t@@ -317,10 +319,10 @@ check_simulation_parameters(struct simulation *sim)
warn_parameter_value("sim->phi_max is not within [0;1]",
sim->phi_max, &return_status);
- check_float("sim->dilatancy_angle", sim->dilatancy_angle, &return_status);
- if (sim->dilatancy_angle < 0.0 || sim->dilatancy_angle > 100.0)
- warn_parameter_value("sim->dilatancy_angle is not within [0;100]",
- sim->dilatancy_angle, &return_status);
+ check_float("sim->dilatancy_constant", sim->dilatancy_constant, &return_status);
+ if (sim->dilatancy_constant < 0.0 || sim->dilatancy_constant > 100.0)
+ warn_parameter_value("sim->dilatancy_constant is not within [0;100]",
+ sim->dilatancy_constant, &return_status);
if (sim->fluid != 0 && sim->fluid != 1)
warn_parameter_value("sim->fluid has an invalid value",
t@@ -407,7 +409,8 @@ compute_critical_state_porosity(struct simulation *sim)
int i;
for (i = 0; i < sim->nz; ++i)
- sim->phi_c[i] = sim->phi_min + (sim->phi_max - sim->phi_min) *sim->I[i];
+ sim->phi_c[i] = sim->phi_min
+ + (sim->phi_max - sim->phi_min) * sim->I[i];
}
void
t@@ -426,40 +429,38 @@ compute_critical_state_friction(struct simulation *sim)
(sim->L_z - sim->z[i]) / sim->P_wall);
}
-void
+static void
compute_friction(struct simulation *sim)
{
int i;
if (sim->transient)
for (i = 0; i < sim->nz; ++i)
- sim->mu[i] = sim->tan_psi[i] + sim->mu_c[i];
+ sim->mu[i] = sim->mu_c[i] - sim->tan_psi[i];
else
for (i = 0; i < sim->nz; ++i)
sim->mu[i] = sim->mu_c[i];
}
-void
+static void
compute_tan_dilatancy_angle(struct simulation *sim)
{
int i;
for (i = 0; i < sim->nz; ++i)
- sim->tan_psi[i] = sim->dilatancy_angle * (sim->phi_c[i] - sim->phi[i]);
+ sim->tan_psi[i] = sim->dilatancy_constant * (sim->phi_c[i] - sim->phi[i]);
}
-void
+static void
compute_porosity_change(struct simulation *sim)
{
int i;
- for (i = 0; i < sim->nz; ++i) {
+ for (i = 0; i < sim->nz; ++i)
sim->phi_dot[i] = sim->tan_psi[i] * sim->gamma_dot_p[i] * sim->phi[i];
- sim->phi[i] += sim->phi_dot[i] * sim->dt;
- }
}
-void
+static void
compute_permeability(struct simulation *sim)
{
int i;
t@@ -478,7 +479,7 @@ shear_strain_rate_plastic(const double fluidity, const double friction)
return fluidity * friction;
}
-void
+static void
compute_shear_strain_rate_plastic(struct simulation *sim)
{
int i;
t@@ -488,7 +489,7 @@ compute_shear_strain_rate_plastic(struct simulation *sim)
sim->mu[i]);
}
-void
+static void
compute_shear_velocity(struct simulation *sim)
{
int i;
t@@ -525,7 +526,7 @@ cooperativity_length(const double A,
return A * d / sqrt(fabs((mu - C / p) - mu_s));
}
-void
+static void
compute_cooperativity_length(struct simulation *sim)
{
int i;
t@@ -554,7 +555,7 @@ local_fluidity(const double p,
return sqrt(p / rho_s * d * d) * ((mu - C / p) - mu_s) / (b * mu);
}
-void
+static void
compute_local_fluidity(struct simulation *sim)
{
int i;
t@@ -734,6 +735,22 @@ print_output(struct simulation *sim, FILE *fp, const int norm)
free(v_x_out);
}
+static void
+temporal_increment(struct simulation *sim)
+{
+ int i;
+
+ if (sim->transient)
+ for (i = 0; i < sim->nz; ++i)
+ sim->phi[i] += sim->phi_dot[i] * sim->dt;
+
+ /*if (sim->fluid)
+ for (i = 1; i <= sim->nz; ++i)
+ sim->p_f_ghost[i] += sim->p_f_dot[i] * sim->dt;*/
+
+ sim->t += sim->dt;
+}
+
int
coupled_shear_solver(struct simulation *sim,
const int max_iter,
t@@ -753,7 +770,7 @@ coupled_shear_solver(struct simulation *sim,
do { /* coupled iterations */
if (sim->transient) {
- copy_values(sim->gamma_dot_p, oldval, sim->nz);
+ copy_values(sim->phi_dot, oldval, sim->nz);
/* step 1 */
compute_inertia_number(sim); /* Eq. 1 */
t@@ -791,26 +808,27 @@ coupled_shear_solver(struct simulation *sim,
/* step 9 */
compute_shear_strain_rate_plastic(sim); /* Eq. 8 */
- compute_inertia_number(sim);
+ compute_inertia_number(sim); /* Eq. 1 */
compute_shear_velocity(sim);
#ifdef DEBUG
- for (i = 0; i < sim->nz; ++i) {
+ /* for (i = 0; i < sim->nz; ++i) { */
+ for (i = sim->nz-1; i < sim->nz; ++i) {
printf("\nsim->t = %g s\n", sim->t);
printf("sim->I[%d] = %g\n", i, sim->I[i]);
printf("sim->phi_c[%d] = %g\n", i, sim->phi_c[i]);
printf("sim->tan_psi[%d] = %g\n", i, sim->tan_psi[i]);
printf("sim->mu_c[%d] = %g\n", i, sim->mu_c[i]);
+ printf("sim->phi[%d] = %g\n", i, sim->phi[i]);
printf("sim->phi_dot[%d] = %g\n", i, sim->phi_dot[i]);
printf("sim->k[%d] = %g\n", i, sim->k[i]);
printf("sim->mu[%d] = %g\n", i, sim->mu[i]);
}
#endif
- /* stable velocity field == coupled solution
- * converged */
+ /* stable porosity change field == coupled solution converged */
if (sim->transient) {
for (i = 0; i < sim->nz; ++i)
- r_norm[i] = fabs(residual(sim->gamma_dot_p[i], oldval[i]));
+ r_norm[i] = fabs(residual(sim->phi_dot[i], oldval[i]));
r_norm_max = max(r_norm, sim->nz);
if (r_norm_max <= rel_tol)
break;
t@@ -858,6 +876,9 @@ coupled_shear_solver(struct simulation *sim,
free(r_norm);
free(oldval);
}
+
+ temporal_increment(sim);
+
return 0;
}
(DIR) diff --git a/simulation.h b/simulation.h
t@@ -84,7 +84,7 @@ struct simulation {
double transient;
double phi_min;
double phi_max;
- double dilatancy_angle;
+ double dilatancy_constant;
/* Fluid parameters */
int fluid; /* flag to switch fluid on (1) or off (0) */
t@@ -93,9 +93,9 @@ struct simulation {
double p_f_mod_freq; /* frequency of fluid pressure variations [s^-1] */
double p_f_mod_phase; /* phase of fluid pressure variations [s^-1] */
double p_f_mod_pulse_time; /* single pressure pulse at this time [s] */
- int p_f_mod_pulse_shape; /* waveform for fluid-pressure pulse */
+ int p_f_mod_pulse_shape; /* waveform for fluid-pressure pulse */
double beta_f; /* adiabatic fluid compressibility [Pa^-1] */
- double alpha; /* adiabatic grain compressibility [Pa^-1] */
+ double alpha; /* adiabatic grain compressibility [Pa^-1] */
double mu_f; /* fluid dynamic viscosity [Pa*s] */
double rho_f; /* fluid density [kg/m^3] */
double D; /* diffusivity [m^2/s], overrides k, beta_f, alpha, mu_f */
t@@ -106,6 +106,7 @@ struct simulation {
double *sigma_n_eff; /* effective normal pressure [Pa] */
double *sigma_n; /* normal stress [Pa] */
double *p_f_ghost; /* fluid pressure [Pa] */
+ double *p_f_dot; /* fluid pressure change [Pa/s] */
double *k; /* hydraulic permeability [m^2] */
double *phi; /* porosity [-] */
double *phi_c; /* critical-state porosity [-] */
t@@ -122,24 +123,9 @@ struct simulation {
void init_sim(struct simulation *sim);
void prepare_arrays(struct simulation *sim);
void free_arrays(struct simulation *sim);
-
void check_simulation_parameters(struct simulation *sim);
-
void lithostatic_pressure_distribution(struct simulation *sim);
-
-void compute_inertia_number(struct simulation *sim);
-void compute_critical_state_porosity(struct simulation *sim);
-void compute_critical_state_friction(struct simulation *sim);
-void compute_porosity_change(struct simulation *sim);
-void compute_permeability(struct simulation *sim);
-void compute_tan_dilatancy_angle(struct simulation *sim);
-
-void compute_cooperativity_length(struct simulation *sim);
-void compute_local_fluidity(struct simulation *sim);
-void compute_shear_strain_rate_plastic(struct simulation *sim);
-void compute_shear_velocity(struct simulation *sim);
void compute_effective_stress(struct simulation *sim);
-void compute_friction(struct simulation *sim);
void set_bc_neumann(double *a,
const int nz,