cngf-pf

commit 8050a4f258c3648cf3bc6f9dad04d4173b6450b6
parent 561aedb1a72628bcb9ffaa31e8303dc460407cf8
Author: Anders Damsgaard <anders@adamsgaard.dk>
Date:   Tue, 12 Jan 2021 14:17:39 +0100

add option -j to specify numerical time step manually

Diffstat:
M
cngf-pf.1
 | 
7
+++++++
M
cngf-pf.c
 | 
10
++++++++--

2 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/cngf-pf.1 b/cngf-pf.1
@@ -24,6 +24,7 @@
 .Op Fl h
 .Op Fl I Ar file-interval
 .Op Fl i Ar fluid-viscosity
+.Op Fl j Ar time-step
 .Op Fl K Ar dilatancy-constant
 .Op Fl k Ar fluid-permeability
 .Op Fl L Ar length
@@ -107,6 +108,12 @@ Simulation time interval between writing output to disk [s] (default
 Fluid dynamic viscosity [Pa*s] (1.787e-3).
 Only relevant with fluid dynamics enabled
 .Fl ( F ) .
+.It Fl j Ar time-step
+Override numerical time step length [s].
+Only relevant with fluid dynamics enabled
+.Fl ( F ) .
+Outside of stability testing, is not recommended to specify the
+time step length manually.
 .It Fl K Ar dilatancy-constant
 Factor relating dilatancy angle to the volume fraction [-] (default
 4.09).  Only relevant with transient granular dynamics enabled
diff --git a/cngf-pf.c b/cngf-pf.c
@@ -38,6 +38,7 @@ usage(void)
 	        "[-h] "
 	        "[-I file-interval] "
 	        "[-i fluid-viscosity] "
+	        "[-j time-step] "
 	        "[-K dilatancy-constant] "
 	        "[-k fluid-permeability] "
 	        "[-L length] "
@@ -87,6 +88,7 @@ main(int argc, char *argv[])
 	normalize = 0;
 	new_phi = sim.phi[0];
 	new_k = sim.k[0];
+	sim.dt = -1.0;
 
 	ARGBEGIN {
 	case 'A':
@@ -134,6 +136,9 @@ main(int argc, char *argv[])
 	case 'i':
 		sim.mu_f = atof(EARGF(usage()));
 		break;
+	case 'j':
+		sim.dt = atof(EARGF(usage()));
+		break;
 	case 'K':
 		sim.dilatancy_constant = atof(EARGF(usage()));
 		break;
@@ -240,17 +245,18 @@ main(int argc, char *argv[])
 			sim.k[i] = new_k;
 
 	lithostatic_pressure_distribution(&sim);
+	compute_effective_stress(&sim);
 
 	if (sim.fluid) {
 		hydrostatic_fluid_pressure_distribution(&sim);
-		if (set_largest_fluid_timestep(&sim, 0.5)) {
+		if (sim.dt <= 0.0 && set_largest_fluid_timestep(&sim, 0.5)) {
 			free_arrays(&sim);
 			return 20;
 		}
 	}
+
 	if (sim.dt > sim.file_dt)
 		sim.dt = sim.file_dt;
-	compute_effective_stress(&sim);
 
 	check_simulation_parameters(&sim);