1 | """Module where global model parameters are set for anuga_1d |
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2 | """ |
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3 | |
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4 | epsilon = 1.0e-12 |
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5 | h0 = 1.0e-6 |
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6 | |
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7 | default_boundary_tag = 'exterior' |
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8 | |
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9 | |
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10 | time_format = '%d/%m/%y %H:%M:%S' |
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11 | |
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12 | min_timestep = 1.0e-6 #Should be computed based on geometry |
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13 | max_timestep = 1000 |
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14 | #This is how: |
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15 | #Define maximal possible speed in open water v_max, e.g. 500m/s (soundspeed?) |
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16 | #Then work out minimal internal distance in mesh r_min and set |
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17 | #min_timestep = r_min/v_max |
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18 | # |
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19 | #Max speeds are calculated in the flux function as |
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20 | # |
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21 | #lambda = v +/- sqrt(gh) |
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22 | # |
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23 | # so with 500 m/s, h ~ 500^2/g = 2500 m well out of the domain of the |
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24 | # shallow water wave equation |
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25 | # |
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26 | #The actual soundspeed can be as high as 1530m/s |
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27 | #(see http://staff.washington.edu/aganse/public.projects/clustering/clustering.html), |
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28 | #but that would only happen with h>225000m in this equation. Why ? |
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29 | #The maximal speed we specify is really related to the max speed |
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30 | #of surface pertubation |
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31 | # |
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32 | |
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33 | |
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34 | v_max = 100 #For use in domain_ext.c |
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35 | sound_speed = 500 |
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36 | |
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37 | |
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38 | max_smallsteps = 50 #Max number of degenerate steps allowed b4 trying first order |
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39 | |
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40 | manning = 0.3 #Manning's friction coefficient |
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41 | g = 9.8 #Gravity |
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42 | #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 |
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43 | #The 'official' average is 9.80665 |
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44 | |
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45 | |
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46 | |
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47 | |
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48 | eta_w = 3.0e-3 #Wind stress coefficient |
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49 | rho_a = 1.2e-3 #Atmospheric density |
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50 | rho_w = 1023 #Fluid density [kg/m^3] (rho_w = 1023 for salt water) |
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51 | |
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52 | |
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53 | #Betas [0;1] control the allowed steepness of gradient for second order |
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54 | #extrapolations. Values of 1 allow the steepes gradients while |
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55 | #lower values are more conservative. Values of 0 correspond to |
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56 | #1'st order extrapolations. |
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57 | # |
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58 | # Large values of beta_h may cause simulations to require more timesteps |
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59 | # as surface will 'hug' closer to the bed. |
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60 | # Small values of beta_h will make code faster, but one may experience |
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61 | # artificial momenta caused by discontinuities in water depths in |
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62 | # the presence of steep slopes. One example of this would be |
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63 | # stationary water 'lapping' upwards to a higher point on the coast. |
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64 | # |
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65 | # |
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66 | # |
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67 | #There are separate betas for the w-limiter and the h-limiter |
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68 | # |
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69 | # |
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70 | # |
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71 | # |
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72 | #Good values are: |
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73 | #beta_w = 0.9 |
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74 | #beta_h = 0.2 |
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75 | |
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76 | |
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77 | |
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78 | beta_w = 1.5 |
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79 | beta_h = 0.2 |
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80 | CFL = 1.0 #FIXME (ole): Is this in use yet?? |
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81 | #(Steve) yes, change domain.CFL to |
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82 | #make changes |
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83 | |
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84 | |
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85 | pmesh_filename = '.\\pmesh' |
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86 | |
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87 | |
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88 | import os, sys |
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89 | |
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90 | if sys.platform == 'win32': |
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91 | #default_datadir = 'C:\grohm_output' |
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92 | default_datadir = '.' |
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93 | else: |
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94 | #default_datadir = os.path.expanduser('~'+os.sep+'grohm_output') |
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95 | default_datadir = '.' |
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96 | |
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97 | |
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98 | use_extensions = True #Try to use C-extensions |
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99 | #use_extensions = False #Do not use C-extensions |
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100 | |
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101 | use_psyco = True #Use psyco optimisations |
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102 | #use_psyco = False #Do not use psyco optimisations |
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103 | |
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104 | |
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105 | optimised_gradient_limiter = True #Use hardwired gradient limiter |
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106 | |
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107 | #Specific to shallow water W.E. |
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108 | minimum_allowed_height = 1.0e-3 #Water depth below which it is considered to be 0 |
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109 | maximum_allowed_speed = 100.0 |
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