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| author |  Robert C. Helling <helling@atdotde.de> | 2017-01-12 21:19:40 +0100 |
|---|---|---|
| committer |  Dirk Hohndel <dirk@hohndel.org> | 2017-01-16 03:17:40 -0800 |
| commit | 7725842383b66fba50c41dbf9f981be38a467135 (patch) | |
| tree | 5bcbe960a3f23ce7895c56ffedef4fd1e79a402a /core/planner.c | |
| parent | fedadc65dbf84164a079f1d9f402290c5e210537 (diff) | |
| download | subsurface-7725842383b66fba50c41dbf9f981be38a467135.tar.gz | |
Use real gas compressibility in planner
Modify formluas for gas use to take into account the
compressibility correction for real gases. This introduces
also the inverse formula to compute the pressure for a given
amount of gas.
Signed-off-by: Robert C. Helling <helling@atdotde.de>
Diffstat (limited to 'core/planner.c')
| -rw-r--r-- | core/planner.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/core/planner.c b/core/planner.c index 118ad751d..7bbb7c0c4 100644 --- a/core/planner.c +++ b/core/planner.c @@ -246,7 +246,7 @@ static void update_cylinder_pressure(struct dive *d, int old_depth, int new_dept if (in_deco) cyl->deco_gas_used.mliter += gas_used.mliter; if (cyl->type.size.mliter) { - delta_p.mbar = gas_used.mliter * 1000.0 / cyl->type.size.mliter; + delta_p.mbar = gas_used.mliter * 1000.0 / cyl->type.size.mliter * gas_compressibility_factor(&cyl->gasmix, cyl->end.mbar / 1000.0); cyl->end.mbar -= delta_p.mbar; } } @@ -830,8 +830,11 @@ static void add_plan_to_notes(struct diveplan *diveplan, struct dive *dive, bool volume = get_volume_units(cyl->gas_used.mliter, NULL, &unit); deco_volume = get_volume_units(cyl->deco_gas_used.mliter, NULL, &unit); if (cyl->type.size.mliter) { - deco_pressure = get_pressure_units(1000.0 * cyl->deco_gas_used.mliter / cyl->type.size.mliter, &pressure_unit); - pressure = get_pressure_units(1000.0 * cyl->gas_used.mliter / cyl->type.size.mliter, &pressure_unit); + int remaining_gas = (double)cyl->end.mbar * cyl->type.size.mliter / 1000.0 / gas_compressibility_factor(&cyl->gasmix, cyl->end.mbar / 1000.0); + double deco_pressure_bar = isothermal_pressure(&cyl->gasmix, 1.0, remaining_gas + cyl->deco_gas_used.mliter, cyl->type.size.mliter) + - cyl->end.mbar / 1000.0; + deco_pressure = get_pressure_units(1000.0 * deco_pressure_bar, &pressure_unit); + pressure = get_pressure_units(cyl->start.mbar - cyl->end.mbar, &pressure_unit); /* Warn if the plan uses more gas than is available in a cylinder * This only works if we have working pressure for the cylinder * 10bar is a made up number - but it seemed silly to pretend you could breathe cylinder down to 0 */ @@ -840,7 +843,8 @@ static void add_plan_to_notes(struct diveplan *diveplan, struct dive *dive, bool translate("gettextFromC", "Warning:"), translate("gettextFromC", "this is more gas than available in the specified cylinder!")); else - if ((float) cyl->end.mbar * cyl->type.size.mliter / 1000.0 < (float) cyl->deco_gas_used.mliter) + if ((float) cyl->end.mbar * cyl->type.size.mliter / 1000.0 / gas_compressibility_factor(&cyl->gasmix, cyl->end.mbar / 1000.0) + < (float) cyl->deco_gas_used.mliter) snprintf(warning, sizeof(warning), " — <span style='color: red;'>%s </span> %s", translate("gettextFromC", "Warning:"), translate("gettextFromC", "not enough reserve for gas sharing on ascent!")); |