source: anuga_work/development/anuga_1d/config.py @ 5535

Last change on this file since 5535 was 5535, checked in by steve, 14 years ago

Changed name of shallow_water_1d to anuga_1d

File size: 2.9 KB
Line 
1"""Module where global model parameters are set
2"""
3
4epsilon = 1.0e-12
5
6default_boundary_tag = 'exterior'
7
8
9time_format = '%d/%m/%y %H:%M:%S'
10
11min_timestep = 1.0e-6 #Should be computed based on geometry
12max_timestep = 1000
13#This is how:
14#Define maximal possible speed in open water v_max, e.g. 500m/s (soundspeed?)
15#Then work out minimal internal distance in mesh r_min and set
16#min_timestep = r_min/v_max
17#
18#Max speeds are calculated in the flux function as
19#
20#lambda = v +/- sqrt(gh)
21#
22# so with 500 m/s, h ~ 500^2/g = 2500 m well out of the domain of the
23# shallow water wave equation
24#
25#The actual soundspeed can be as high as 1530m/s
26#(see http://staff.washington.edu/aganse/public.projects/clustering/clustering.html),
27#but that would only happen with h>225000m in this equation. Why ?
28#The maximal speed we specify is really related to the max speed
29#of surface pertubation
30#
31
32
33v_max = 100 #For use in domain_ext.c
34sound_speed = 500
35
36
37max_smallsteps = 50  #Max number of degenerate steps allowed b4 trying first order
38
39manning = 0.3  #Manning's friction coefficient
40g = 9.8       #Gravity
41#g(phi) = 9780313 * (1 + 0.0053024 sin(phi)**2 - 0.000 0059 sin(2*phi)**2) micro m/s**2, where phi is the latitude
42#The 'official' average is 9.80665
43
44
45
46
47eta_w = 3.0e-3 #Wind stress coefficient
48rho_a = 1.2e-3 #Atmospheric density
49rho_w = 1023   #Fluid density [kg/m^3] (rho_w = 1023 for salt water)
50
51
52#Betas [0;1] control the allowed steepness of gradient for second order
53#extrapolations. Values of 1 allow the steepes gradients while
54#lower values are more conservative. Values of 0 correspond to
55#1'st order extrapolations.
56#
57# Large values of beta_h may cause simulations to require more timesteps
58# as surface will 'hug' closer to the bed.
59# Small values of beta_h will make code faster, but one may experience
60# artificial momenta caused by discontinuities in water depths in
61# the presence of steep slopes. One example of this would be
62# stationary water 'lapping' upwards to a higher point on the coast.
63#
64#
65#
66#There are separate betas for the w-limiter and the h-limiter
67#
68#
69#
70#
71#Good values are:
72#beta_w = 0.9
73#beta_h = 0.2
74
75
76
77beta_w = 0.9
78beta_h = 0.2
79CFL = 1.0  #FIXME (ole): Is this in use yet??
80           #(Steve) yes, change domain.CFL to
81           #make changes
82
83
84pmesh_filename = '.\\pmesh'
85
86
87import os, sys
88
89if sys.platform == 'win32':
90    #default_datadir = 'C:\grohm_output'
91    default_datadir = '.'
92else:
93    #default_datadir = os.path.expanduser('~'+os.sep+'grohm_output')
94    default_datadir = '.'
95
96
97use_extensions = True    #Try to use C-extensions
98#use_extensions = False   #Do not use C-extensions
99
100use_psyco = True  #Use psyco optimisations
101#use_psyco = False  #Do not use psyco optimisations
102
103
104optimised_gradient_limiter = True #Use hardwired gradient limiter
105
106#Specific to shallow water W.E.
107minimum_allowed_height = 1.0e-3 #Water depth below which it is considered to be 0
108maximum_allowed_speed = 100.0
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