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600 lines
23 KiB
C
600 lines
23 KiB
C
/* calculate deco values
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* based on Bühlmann ZHL-16b
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* based on an implemention by heinrichs weikamp for the DR5
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* the original file was given to Subsurface under the GPLv2
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* by Matthias Heinrichs
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*
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* The implementation below is a fairly complete rewrite since then
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* (C) Robert C. Helling 2013 and released under the GPLv2
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*
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* add_segment() - add <seconds> at the given pressure, breathing gasmix
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* deco_allowed_depth() - ceiling based on lead tissue, surface pressure, 3m increments or smooth
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* set_gf() - set Buehlmann gradient factors
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* clear_deco()
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* cache_deco_state()
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* restore_deco_state()
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* dump_tissues()
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*/
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#include <math.h>
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#include <string.h>
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#include "dive.h"
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#include <assert.h>
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#include <planner.h>
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#define cube(x) (x * x * x)
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// Subsurface appears to produce marginally less conservative plans than our benchmarks
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// Introduce 1.2% additional conservatism
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#define subsurface_conservatism_factor 1.012
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extern bool in_planner();
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extern pressure_t first_ceiling_pressure;
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//! Option structure for Buehlmann decompression.
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struct buehlmann_config {
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double satmult; //! safety at inert gas accumulation as percentage of effect (more than 100).
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double desatmult; //! safety at inert gas depletion as percentage of effect (less than 100).
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unsigned int last_deco_stop_in_mtr; //! depth of last_deco_stop.
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double gf_high; //! gradient factor high (at surface).
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double gf_low; //! gradient factor low (at bottom/start of deco calculation).
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double gf_low_position_min; //! gf_low_position below surface_min_shallow.
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bool gf_low_at_maxdepth; //! if true, gf_low applies at max depth instead of at deepest ceiling.
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};
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struct buehlmann_config buehlmann_config = {
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.satmult = 1.0,
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.desatmult = 1.01,
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.last_deco_stop_in_mtr = 0,
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.gf_high = 0.75,
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.gf_low = 0.35,
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.gf_low_position_min = 1.0,
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.gf_low_at_maxdepth = false
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};
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//! Option structure for VPM-B decompression.
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struct vpmb_config {
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double crit_radius_N2; //! Critical radius of N2 nucleon (microns).
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double crit_radius_He; //! Critical radius of He nucleon (microns).
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double crit_volume_lambda; //! Constant corresponding to critical gas volume (bar * min).
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double gradient_of_imperm; //! Gradient after which bubbles become impermeable (bar).
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double surface_tension_gamma; //! Nucleons surface tension constant (N / bar = m2).
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double skin_compression_gammaC; //! Skin compression gammaC (N / bar = m2).
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double regeneration_time; //! Time needed for the bubble to regenerate to the start radius (min).
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double other_gases_pressure; //! Always present pressure of other gasses in tissues (bar).
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};
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struct vpmb_config vpmb_config = {
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.crit_radius_N2 = 0.55,
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.crit_radius_He = 0.45,
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.crit_volume_lambda = 199.58,
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.gradient_of_imperm = 8.30865, // = 8.2 atm
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.surface_tension_gamma = 0.18137175, // = 0.0179 N/msw
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.skin_compression_gammaC = 2.6040525, // = 0.257 N/msw
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.regeneration_time = 20160.0,
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.other_gases_pressure = 0.1359888
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};
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const double buehlmann_N2_a[] = { 1.1696, 1.0, 0.8618, 0.7562,
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0.62, 0.5043, 0.441, 0.4,
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0.375, 0.35, 0.3295, 0.3065,
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0.2835, 0.261, 0.248, 0.2327 };
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const double buehlmann_N2_b[] = { 0.5578, 0.6514, 0.7222, 0.7825,
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0.8126, 0.8434, 0.8693, 0.8910,
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0.9092, 0.9222, 0.9319, 0.9403,
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0.9477, 0.9544, 0.9602, 0.9653 };
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const double buehlmann_N2_t_halflife[] = { 5.0, 8.0, 12.5, 18.5,
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27.0, 38.3, 54.3, 77.0,
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109.0, 146.0, 187.0, 239.0,
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305.0, 390.0, 498.0, 635.0 };
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const double buehlmann_N2_factor_expositon_one_second[] = {
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2.30782347297664E-003, 1.44301447809736E-003, 9.23769302935806E-004, 6.24261986779007E-004,
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4.27777107246730E-004, 3.01585140931371E-004, 2.12729727268379E-004, 1.50020603047807E-004,
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1.05980191127841E-004, 7.91232600646508E-005, 6.17759153688224E-005, 4.83354552742732E-005,
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3.78761777920511E-005, 2.96212356654113E-005, 2.31974277413727E-005, 1.81926738960225E-005
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};
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const double buehlmann_He_a[] = { 1.6189, 1.383, 1.1919, 1.0458,
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0.922, 0.8205, 0.7305, 0.6502,
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0.595, 0.5545, 0.5333, 0.5189,
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0.5181, 0.5176, 0.5172, 0.5119 };
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const double buehlmann_He_b[] = { 0.4770, 0.5747, 0.6527, 0.7223,
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0.7582, 0.7957, 0.8279, 0.8553,
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0.8757, 0.8903, 0.8997, 0.9073,
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0.9122, 0.9171, 0.9217, 0.9267 };
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const double buehlmann_He_t_halflife[] = { 1.88, 3.02, 4.72, 6.99,
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10.21, 14.48, 20.53, 29.11,
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41.20, 55.19, 70.69, 90.34,
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115.29, 147.42, 188.24, 240.03 };
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const double buehlmann_He_factor_expositon_one_second[] = {
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6.12608039419837E-003, 3.81800836683133E-003, 2.44456078654209E-003, 1.65134647076792E-003,
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1.13084424730725E-003, 7.97503165599123E-004, 5.62552521860549E-004, 3.96776399429366E-004,
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2.80360036664540E-004, 2.09299583354805E-004, 1.63410794820518E-004, 1.27869320250551E-004,
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1.00198406028040E-004, 7.83611475491108E-005, 6.13689891868496E-005, 4.81280465299827E-005
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};
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const double conservatism_lvls[] = { 1.0, 1.05, 1.12, 1.22, 1.35 };
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/* Inspired gas loading equations depend on the partial pressure of inert gas in the alveolar.
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* P_alv = (P_amb - P_H2O + (1 - Rq) / Rq * P_CO2) * f
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* where:
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* P_alv alveolar partial pressure of inert gas
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* P_amb ambient pressure
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* P_H2O water vapour partial pressure = ~0.0627 bar
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* P_CO2 carbon dioxide partial pressure = ~0.0534 bar
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* Rq respiratory quotient (O2 consumption / CO2 production)
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* f fraction of inert gas
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*
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* In our calculations, we simplify this to use an effective water vapour pressure
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* WV = P_H20 - (1 - Rq) / Rq * P_CO2
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*
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* Buhlmann ignored the contribution of CO2 (i.e. Rq = 1.0), whereas Schreiner adopted Rq = 0.8.
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* WV_Buhlmann = PP_H2O = 0.0627 bar
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* WV_Schreiner = 0.0627 - (1 - 0.8) / Rq * 0.0534 = 0.0493 bar
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* Buhlmann calculations use the Buhlmann value, VPM-B calculations use the Schreiner value.
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*/
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#define WV_PRESSURE 0.0627 // water vapor pressure in bar, based on respiratory quotient Rq = 1.0 (Buhlmann value)
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#define WV_PRESSURE_SCHREINER 0.0493 // water vapor pressure in bar, based on respiratory quotient Rq = 0.8 (Schreiner value)
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#define DECO_STOPS_MULTIPLIER_MM 3000.0
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#define NITROGEN_FRACTION 0.79
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double tissue_n2_sat[16];
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double tissue_he_sat[16];
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int ci_pointing_to_guiding_tissue;
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double gf_low_pressure_this_dive;
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#define TISSUE_ARRAY_SZ sizeof(tissue_n2_sat)
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double tolerated_by_tissue[16];
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double tissue_inertgas_saturation[16];
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double buehlmann_inertgas_a[16], buehlmann_inertgas_b[16];
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double max_n2_crushing_pressure[16];
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double max_he_crushing_pressure[16];
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double crushing_onset_tension[16]; // total inert gas tension in the t* moment
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double n2_regen_radius[16]; // rs
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double he_regen_radius[16];
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double max_ambient_pressure; // last moment we were descending
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double bottom_n2_gradient[16];
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double bottom_he_gradient[16];
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double initial_n2_gradient[16];
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double initial_he_gradient[16];
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double get_crit_radius_He()
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{
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if (prefs.conservatism_level <= 4)
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return vpmb_config.crit_radius_He * conservatism_lvls[prefs.conservatism_level] * subsurface_conservatism_factor;
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return vpmb_config.crit_radius_He;
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}
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double get_crit_radius_N2()
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{
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if (prefs.conservatism_level <= 4)
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return vpmb_config.crit_radius_N2 * conservatism_lvls[prefs.conservatism_level] * subsurface_conservatism_factor;
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return vpmb_config.crit_radius_N2;
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}
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// Solve another cubic equation, this time
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// x^3 - B x - C == 0
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// Use trigonometric formula for negative discriminants (see Wikipedia for details)
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double solve_cubic2(double B, double C)
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{
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double discriminant = 27 * C * C - 4 * cube(B);
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if (discriminant < 0.0) {
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return 2.0 * sqrt(B / 3.0) * cos(acos(3.0 * C * sqrt(3.0 / B) / (2.0 * B)) / 3.0);
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}
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double denominator = pow(9 * C + sqrt(3 * discriminant), 1 / 3.0);
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return pow(2.0 / 3.0, 1.0 / 3.0) * B / denominator + denominator / pow(18.0, 1.0 / 3.0);
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}
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// This is a simplified formula avoiding radii. It uses the fact that Boyle's law says
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// pV = (G + P_amb) / G^3 is constant to solve for the new gradient G.
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double update_gradient(double next_stop_pressure, double first_gradient)
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{
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double B = cube(first_gradient) / (first_ceiling_pressure.mbar / 1000.0 + first_gradient);
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double C = next_stop_pressure * B;
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double new_gradient = solve_cubic2(B, C);
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if (new_gradient < 0.0)
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report_error("Negative gradient encountered!");
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return new_gradient;
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}
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double vpmb_tolerated_ambient_pressure(double reference_pressure, int ci)
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{
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double n2_gradient, he_gradient, total_gradient;
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if (reference_pressure >= first_ceiling_pressure.mbar / 1000.0 || !first_ceiling_pressure.mbar) {
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n2_gradient = bottom_n2_gradient[ci];
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he_gradient = bottom_he_gradient[ci];
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} else {
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n2_gradient = update_gradient(reference_pressure, bottom_n2_gradient[ci]);
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he_gradient = update_gradient(reference_pressure, bottom_he_gradient[ci]);
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}
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total_gradient = ((n2_gradient * tissue_n2_sat[ci]) + (he_gradient * tissue_he_sat[ci])) / (tissue_n2_sat[ci] + tissue_he_sat[ci]);
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return tissue_n2_sat[ci] + tissue_he_sat[ci] + vpmb_config.other_gases_pressure - total_gradient;
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}
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double tissue_tolerance_calc(const struct dive *dive, double pressure)
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{
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int ci = -1;
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double ret_tolerance_limit_ambient_pressure = 0.0;
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double gf_high = buehlmann_config.gf_high;
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double gf_low = buehlmann_config.gf_low;
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double surface = get_surface_pressure_in_mbar(dive, true) / 1000.0;
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double lowest_ceiling = 0.0;
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double tissue_lowest_ceiling[16];
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if (prefs.deco_mode != VPMB) {
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for (ci = 0; ci < 16; ci++) {
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tissue_inertgas_saturation[ci] = tissue_n2_sat[ci] + tissue_he_sat[ci];
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buehlmann_inertgas_a[ci] = ((buehlmann_N2_a[ci] * tissue_n2_sat[ci]) + (buehlmann_He_a[ci] * tissue_he_sat[ci])) / tissue_inertgas_saturation[ci];
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buehlmann_inertgas_b[ci] = ((buehlmann_N2_b[ci] * tissue_n2_sat[ci]) + (buehlmann_He_b[ci] * tissue_he_sat[ci])) / tissue_inertgas_saturation[ci];
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/* tolerated = (tissue_inertgas_saturation - buehlmann_inertgas_a) * buehlmann_inertgas_b; */
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tissue_lowest_ceiling[ci] = (buehlmann_inertgas_b[ci] * tissue_inertgas_saturation[ci] - gf_low * buehlmann_inertgas_a[ci] * buehlmann_inertgas_b[ci]) /
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((1.0 - buehlmann_inertgas_b[ci]) * gf_low + buehlmann_inertgas_b[ci]);
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if (tissue_lowest_ceiling[ci] > lowest_ceiling)
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lowest_ceiling = tissue_lowest_ceiling[ci];
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if (!buehlmann_config.gf_low_at_maxdepth) {
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if (lowest_ceiling > gf_low_pressure_this_dive)
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gf_low_pressure_this_dive = lowest_ceiling;
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}
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}
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for (ci = 0; ci < 16; ci++) {
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double tolerated;
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if ((surface / buehlmann_inertgas_b[ci] + buehlmann_inertgas_a[ci] - surface) * gf_high + surface <
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(gf_low_pressure_this_dive / buehlmann_inertgas_b[ci] + buehlmann_inertgas_a[ci] - gf_low_pressure_this_dive) * gf_low + gf_low_pressure_this_dive)
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tolerated = (-buehlmann_inertgas_a[ci] * buehlmann_inertgas_b[ci] * (gf_high * gf_low_pressure_this_dive - gf_low * surface) -
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(1.0 - buehlmann_inertgas_b[ci]) * (gf_high - gf_low) * gf_low_pressure_this_dive * surface +
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buehlmann_inertgas_b[ci] * (gf_low_pressure_this_dive - surface) * tissue_inertgas_saturation[ci]) /
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(-buehlmann_inertgas_a[ci] * buehlmann_inertgas_b[ci] * (gf_high - gf_low) +
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(1.0 - buehlmann_inertgas_b[ci]) * (gf_low * gf_low_pressure_this_dive - gf_high * surface) +
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buehlmann_inertgas_b[ci] * (gf_low_pressure_this_dive - surface));
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else
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tolerated = ret_tolerance_limit_ambient_pressure;
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tolerated_by_tissue[ci] = tolerated;
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if (tolerated >= ret_tolerance_limit_ambient_pressure) {
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ci_pointing_to_guiding_tissue = ci;
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ret_tolerance_limit_ambient_pressure = tolerated;
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}
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}
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} else {
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// VPM-B ceiling
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double reference_pressure;
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ret_tolerance_limit_ambient_pressure = pressure;
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// The Boyle compensated gradient depends on ambient pressure. For the ceiling, this should set the ambient pressure.
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do {
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reference_pressure = ret_tolerance_limit_ambient_pressure;
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ret_tolerance_limit_ambient_pressure = 0.0;
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for (ci = 0; ci < 16; ci++) {
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double tolerated = vpmb_tolerated_ambient_pressure(reference_pressure, ci);
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if (tolerated >= ret_tolerance_limit_ambient_pressure) {
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ci_pointing_to_guiding_tissue = ci;
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ret_tolerance_limit_ambient_pressure = tolerated;
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}
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tolerated_by_tissue[ci] = tolerated;
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}
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// We are doing ok if the gradient was computed within ten centimeters of the ceiling.
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} while (fabs(ret_tolerance_limit_ambient_pressure - reference_pressure) > 0.01);
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}
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return ret_tolerance_limit_ambient_pressure;
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}
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/*
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* Return buelman factor for a particular period and tissue index.
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*
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* We cache the last factor, since we commonly call this with the
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* same values... We have a special "fixed cache" for the one second
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* case, although I wonder if that's even worth it considering the
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* more general-purpose cache.
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*/
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struct factor_cache {
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int last_period;
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double last_factor;
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};
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double n2_factor(int period_in_seconds, int ci)
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{
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static struct factor_cache cache[16];
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if (period_in_seconds == 1)
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return buehlmann_N2_factor_expositon_one_second[ci];
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if (period_in_seconds != cache[ci].last_period) {
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cache[ci].last_period = period_in_seconds;
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cache[ci].last_factor = 1 - pow(2.0, -period_in_seconds / (buehlmann_N2_t_halflife[ci] * 60));
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}
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return cache[ci].last_factor;
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}
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double he_factor(int period_in_seconds, int ci)
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{
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static struct factor_cache cache[16];
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if (period_in_seconds == 1)
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return buehlmann_He_factor_expositon_one_second[ci];
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if (period_in_seconds != cache[ci].last_period) {
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cache[ci].last_period = period_in_seconds;
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cache[ci].last_factor = 1 - pow(2.0, -period_in_seconds / (buehlmann_He_t_halflife[ci] * 60));
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}
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return cache[ci].last_factor;
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}
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double calc_surface_phase(double surface_pressure, double he_pressure, double n2_pressure, double he_time_constant, double n2_time_constant)
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{
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double inspired_n2 = (surface_pressure - ((in_planner() && (prefs.deco_mode == VPMB)) ? WV_PRESSURE_SCHREINER : WV_PRESSURE)) * NITROGEN_FRACTION;
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if (n2_pressure > inspired_n2)
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return (he_pressure / he_time_constant + (n2_pressure - inspired_n2) / n2_time_constant) / (he_pressure + n2_pressure - inspired_n2);
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if (he_pressure + n2_pressure >= inspired_n2){
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double gradient_decay_time = 1.0 / (n2_time_constant - he_time_constant) * log ((inspired_n2 - n2_pressure) / he_pressure);
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double gradients_integral = he_pressure / he_time_constant * (1.0 - exp(-he_time_constant * gradient_decay_time)) + (n2_pressure - inspired_n2) / n2_time_constant * (1.0 - exp(-n2_time_constant * gradient_decay_time));
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return gradients_integral / (he_pressure + n2_pressure - inspired_n2);
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}
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return 0;
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}
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void vpmb_start_gradient()
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{
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int ci;
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for (ci = 0; ci < 16; ++ci) {
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initial_n2_gradient[ci] = bottom_n2_gradient[ci] = 2.0 * (vpmb_config.surface_tension_gamma / vpmb_config.skin_compression_gammaC) * ((vpmb_config.skin_compression_gammaC - vpmb_config.surface_tension_gamma) / n2_regen_radius[ci]);
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initial_he_gradient[ci] = bottom_he_gradient[ci] = 2.0 * (vpmb_config.surface_tension_gamma / vpmb_config.skin_compression_gammaC) * ((vpmb_config.skin_compression_gammaC - vpmb_config.surface_tension_gamma) / he_regen_radius[ci]);
|
|
}
|
|
}
|
|
|
|
void vpmb_next_gradient(double deco_time, double surface_pressure)
|
|
{
|
|
int ci;
|
|
double n2_b, n2_c;
|
|
double he_b, he_c;
|
|
double desat_time;
|
|
deco_time /= 60.0;
|
|
|
|
for (ci = 0; ci < 16; ++ci) {
|
|
desat_time = deco_time + calc_surface_phase(surface_pressure, tissue_he_sat[ci], tissue_n2_sat[ci], log(2.0) / buehlmann_He_t_halflife[ci], log(2.0) / buehlmann_N2_t_halflife[ci]);
|
|
|
|
n2_b = initial_n2_gradient[ci] + (vpmb_config.crit_volume_lambda * vpmb_config.surface_tension_gamma) / (vpmb_config.skin_compression_gammaC * desat_time);
|
|
he_b = initial_he_gradient[ci] + (vpmb_config.crit_volume_lambda * vpmb_config.surface_tension_gamma) / (vpmb_config.skin_compression_gammaC * desat_time);
|
|
|
|
n2_c = vpmb_config.surface_tension_gamma * vpmb_config.surface_tension_gamma * vpmb_config.crit_volume_lambda * max_n2_crushing_pressure[ci];
|
|
n2_c = n2_c / (vpmb_config.skin_compression_gammaC * vpmb_config.skin_compression_gammaC * desat_time);
|
|
he_c = vpmb_config.surface_tension_gamma * vpmb_config.surface_tension_gamma * vpmb_config.crit_volume_lambda * max_he_crushing_pressure[ci];
|
|
he_c = he_c / (vpmb_config.skin_compression_gammaC * vpmb_config.skin_compression_gammaC * desat_time);
|
|
|
|
bottom_n2_gradient[ci] = 0.5 * ( n2_b + sqrt(n2_b * n2_b - 4.0 * n2_c));
|
|
bottom_he_gradient[ci] = 0.5 * ( he_b + sqrt(he_b * he_b - 4.0 * he_c));
|
|
}
|
|
}
|
|
|
|
// A*r^3 - B*r^2 - C == 0
|
|
// Solved with the help of mathematica
|
|
|
|
double solve_cubic(double A, double B, double C)
|
|
{
|
|
double BA = B/A;
|
|
double CA = C/A;
|
|
|
|
double discriminant = CA * (4 * cube(BA) + 27 * CA);
|
|
|
|
// Let's make sure we have a real solution:
|
|
if (discriminant < 0.0) {
|
|
// This should better not happen
|
|
report_error("Complex solution for inner pressure encountered!\n A=%f\tB=%f\tC=%f\n", A, B, C);
|
|
return 0.0;
|
|
}
|
|
double denominator = pow(cube(BA) + 1.5 * (9 * CA + sqrt(3.0) * sqrt(discriminant)), 1/3.0);
|
|
return (BA + BA * BA / denominator + denominator) / 3.0;
|
|
|
|
}
|
|
|
|
|
|
void nuclear_regeneration(double time)
|
|
{
|
|
time /= 60.0;
|
|
int ci;
|
|
double crushing_radius_N2, crushing_radius_He;
|
|
for (ci = 0; ci < 16; ++ci) {
|
|
//rm
|
|
crushing_radius_N2 = 1.0 / (max_n2_crushing_pressure[ci] / (2.0 * (vpmb_config.skin_compression_gammaC - vpmb_config.surface_tension_gamma)) + 1.0 / get_crit_radius_N2());
|
|
crushing_radius_He = 1.0 / (max_he_crushing_pressure[ci] / (2.0 * (vpmb_config.skin_compression_gammaC - vpmb_config.surface_tension_gamma)) + 1.0 / get_crit_radius_He());
|
|
//rs
|
|
n2_regen_radius[ci] = crushing_radius_N2 + (get_crit_radius_N2() - crushing_radius_N2) * (1.0 - exp (-time / vpmb_config.regeneration_time));
|
|
he_regen_radius[ci] = crushing_radius_He + (get_crit_radius_He() - crushing_radius_He) * (1.0 - exp (-time / vpmb_config.regeneration_time));
|
|
}
|
|
}
|
|
|
|
|
|
// Calculates the nucleons inner pressure during the impermeable period
|
|
double calc_inner_pressure(double crit_radius, double onset_tension, double current_ambient_pressure)
|
|
{
|
|
double onset_radius = 1.0 / (vpmb_config.gradient_of_imperm / (2.0 * (vpmb_config.skin_compression_gammaC - vpmb_config.surface_tension_gamma)) + 1.0 / crit_radius);
|
|
|
|
|
|
double A = current_ambient_pressure - vpmb_config.gradient_of_imperm + (2.0 * (vpmb_config.skin_compression_gammaC - vpmb_config.surface_tension_gamma)) / onset_radius;
|
|
double B = 2.0 * (vpmb_config.skin_compression_gammaC - vpmb_config.surface_tension_gamma);
|
|
double C = onset_tension * pow(onset_radius, 3);
|
|
|
|
double current_radius = solve_cubic(A, B, C);
|
|
|
|
return onset_tension * onset_radius * onset_radius * onset_radius / (current_radius * current_radius * current_radius);
|
|
}
|
|
|
|
// Calculates the crushing pressure in the given moment. Updates crushing_onset_tension and critical radius if needed
|
|
void calc_crushing_pressure(double pressure)
|
|
{
|
|
int ci;
|
|
double gradient;
|
|
double gas_tension;
|
|
double n2_crushing_pressure, he_crushing_pressure;
|
|
double n2_inner_pressure, he_inner_pressure;
|
|
|
|
for (ci = 0; ci < 16; ++ci) {
|
|
gas_tension = tissue_n2_sat[ci] + tissue_he_sat[ci] + vpmb_config.other_gases_pressure;
|
|
gradient = pressure - gas_tension;
|
|
|
|
if (gradient <= vpmb_config.gradient_of_imperm) { // permeable situation
|
|
n2_crushing_pressure = he_crushing_pressure = gradient;
|
|
crushing_onset_tension[ci] = gas_tension;
|
|
}
|
|
else { // impermeable
|
|
if (max_ambient_pressure >= pressure)
|
|
return;
|
|
|
|
n2_inner_pressure = calc_inner_pressure(get_crit_radius_N2(), crushing_onset_tension[ci], pressure);
|
|
he_inner_pressure = calc_inner_pressure(get_crit_radius_He(), crushing_onset_tension[ci], pressure);
|
|
|
|
n2_crushing_pressure = pressure - n2_inner_pressure;
|
|
he_crushing_pressure = pressure - he_inner_pressure;
|
|
}
|
|
max_n2_crushing_pressure[ci] = MAX(max_n2_crushing_pressure[ci], n2_crushing_pressure);
|
|
max_he_crushing_pressure[ci] = MAX(max_he_crushing_pressure[ci], he_crushing_pressure);
|
|
}
|
|
max_ambient_pressure = MAX(pressure, max_ambient_pressure);
|
|
}
|
|
|
|
/* add period_in_seconds at the given pressure and gas to the deco calculation */
|
|
void add_segment(double pressure, const struct gasmix *gasmix, int period_in_seconds, int ccpo2, const struct dive *dive, int sac)
|
|
{
|
|
int ci;
|
|
struct gas_pressures pressures;
|
|
|
|
fill_pressures(&pressures, pressure - ((in_planner() && (prefs.deco_mode == VPMB)) ? WV_PRESSURE_SCHREINER : WV_PRESSURE),
|
|
gasmix, (double) ccpo2 / 1000.0, dive->dc.divemode);
|
|
|
|
if (buehlmann_config.gf_low_at_maxdepth && pressure > gf_low_pressure_this_dive)
|
|
gf_low_pressure_this_dive = pressure;
|
|
|
|
for (ci = 0; ci < 16; ci++) {
|
|
double pn2_oversat = pressures.n2 - tissue_n2_sat[ci];
|
|
double phe_oversat = pressures.he - tissue_he_sat[ci];
|
|
double n2_f = n2_factor(period_in_seconds, ci);
|
|
double he_f = he_factor(period_in_seconds, ci);
|
|
double n2_satmult = pn2_oversat > 0 ? buehlmann_config.satmult : buehlmann_config.desatmult;
|
|
double he_satmult = phe_oversat > 0 ? buehlmann_config.satmult : buehlmann_config.desatmult;
|
|
|
|
tissue_n2_sat[ci] += n2_satmult * pn2_oversat * n2_f;
|
|
tissue_he_sat[ci] += he_satmult * phe_oversat * he_f;
|
|
}
|
|
if(prefs.deco_mode == VPMB)
|
|
calc_crushing_pressure(pressure);
|
|
return;
|
|
}
|
|
|
|
void dump_tissues()
|
|
{
|
|
int ci;
|
|
printf("N2 tissues:");
|
|
for (ci = 0; ci < 16; ci++)
|
|
printf(" %6.3e", tissue_n2_sat[ci]);
|
|
printf("\nHe tissues:");
|
|
for (ci = 0; ci < 16; ci++)
|
|
printf(" %6.3e", tissue_he_sat[ci]);
|
|
printf("\n");
|
|
}
|
|
|
|
void clear_deco(double surface_pressure)
|
|
{
|
|
int ci;
|
|
for (ci = 0; ci < 16; ci++) {
|
|
tissue_n2_sat[ci] = (surface_pressure - ((in_planner() && (prefs.deco_mode == VPMB)) ? WV_PRESSURE_SCHREINER : WV_PRESSURE)) * N2_IN_AIR / 1000;
|
|
tissue_he_sat[ci] = 0.0;
|
|
max_n2_crushing_pressure[ci] = 0.0;
|
|
max_he_crushing_pressure[ci] = 0.0;
|
|
n2_regen_radius[ci] = get_crit_radius_N2();
|
|
he_regen_radius[ci] = get_crit_radius_He();
|
|
}
|
|
gf_low_pressure_this_dive = surface_pressure;
|
|
if (!buehlmann_config.gf_low_at_maxdepth)
|
|
gf_low_pressure_this_dive += buehlmann_config.gf_low_position_min;
|
|
max_ambient_pressure = 0.0;
|
|
}
|
|
|
|
void cache_deco_state(char **cached_datap)
|
|
{
|
|
char *data = *cached_datap;
|
|
|
|
if (!data) {
|
|
data = malloc(2 * TISSUE_ARRAY_SZ + sizeof(double) + sizeof(int));
|
|
*cached_datap = data;
|
|
}
|
|
memcpy(data, tissue_n2_sat, TISSUE_ARRAY_SZ);
|
|
data += TISSUE_ARRAY_SZ;
|
|
memcpy(data, tissue_he_sat, TISSUE_ARRAY_SZ);
|
|
data += TISSUE_ARRAY_SZ;
|
|
memcpy(data, &gf_low_pressure_this_dive, sizeof(double));
|
|
data += sizeof(double);
|
|
memcpy(data, &ci_pointing_to_guiding_tissue, sizeof(int));
|
|
}
|
|
|
|
void restore_deco_state(char *data)
|
|
{
|
|
memcpy(tissue_n2_sat, data, TISSUE_ARRAY_SZ);
|
|
data += TISSUE_ARRAY_SZ;
|
|
memcpy(tissue_he_sat, data, TISSUE_ARRAY_SZ);
|
|
data += TISSUE_ARRAY_SZ;
|
|
memcpy(&gf_low_pressure_this_dive, data, sizeof(double));
|
|
data += sizeof(double);
|
|
memcpy(&ci_pointing_to_guiding_tissue, data, sizeof(int));
|
|
}
|
|
|
|
unsigned int deco_allowed_depth(double tissues_tolerance, double surface_pressure, struct dive *dive, bool smooth)
|
|
{
|
|
unsigned int depth;
|
|
double pressure_delta;
|
|
|
|
/* Avoid negative depths */
|
|
pressure_delta = tissues_tolerance > surface_pressure ? tissues_tolerance - surface_pressure : 0.0;
|
|
|
|
depth = rel_mbar_to_depth(pressure_delta * 1000, dive);
|
|
|
|
if (!smooth)
|
|
depth = ceil(depth / DECO_STOPS_MULTIPLIER_MM) * DECO_STOPS_MULTIPLIER_MM;
|
|
|
|
if (depth > 0 && depth < buehlmann_config.last_deco_stop_in_mtr * 1000)
|
|
depth = buehlmann_config.last_deco_stop_in_mtr * 1000;
|
|
|
|
return depth;
|
|
}
|
|
|
|
void set_gf(short gflow, short gfhigh, bool gf_low_at_maxdepth)
|
|
{
|
|
if (gflow != -1)
|
|
buehlmann_config.gf_low = (double)gflow / 100.0;
|
|
if (gfhigh != -1)
|
|
buehlmann_config.gf_high = (double)gfhigh / 100.0;
|
|
buehlmann_config.gf_low_at_maxdepth = gf_low_at_maxdepth;
|
|
}
|