mifr/subsurface
1
0
Fork 0
mirror of https://github.com/subsurface/subsurface.git synced 2025-01-31 20:03:24 +00:00
Code Issues Projects Releases Packages Wiki Activity

Compute and display gas density

Browse source 
This appears to be critical for work of breathing so it might be
worthwhile to compute. So far only in infobox.

For background, see

https://www.youtube.com/watch?v=QBajM3xmOtc

Signed-off-by: Robert C. Helling <helling@atdotde.de>
This commit is contained in:
Robert C. Helling 2017-05-12 15:36:24 +02:00 • committed by Dirk Hohndel
parent e6d884cf26
commit bb6ceba4ac
5 changed files with 17 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
core/dive.h
View file

@ -139,6 +139,8 @@ extern int units_to_sac(double volume);
extern int gas_volume(cylinder_t *cyl, pressure_t p);
extern double gas_compressibility_factor(struct gasmix *gas, double bar);
extern double isothermal_pressure(struct gasmix *gas, double p1, int volume1, int volume2);
extern double gas_density(struct gasmix *gas, int pressure);
static inline int get_o2(const struct gasmix *mix)

8
core/gas-model.c
View file

@ -9,6 +9,8 @@
#define virial_m1(C, x1, x2, x3) (C[0]*x1+C[1]*x2+C[2]*x3)
/*
* Z = pV/nRT
*
* Cubic virial least-square coefficients for O2/N2/He based on data from
*
* PERRY’S CHEMICAL ENGINEERS’ HANDBOOK SEVENTH EDITION
@ -73,3 +75,9 @@ double isothermal_pressure(struct gasmix *gas, double p1, int volume1, int volum
return p_ideal * gas_compressibility_factor(gas, p_ideal);
}
inline double gas_density(struct gasmix *gas, int pressure) {
int density = gas->he.permille * HE_DENSITY + gas->o2.permille * O2_DENSITY + (1000 - gas->he.permille - gas->o2.permille) * N2_DENSITY;
return density * (double) pressure / gas_compressibility_factor(gas, pressure / 1000.0) / SURFACE_PRESSURE / 1000000.0;
}

6
core/profile.c
View file

@ -1151,6 +1151,7 @@ static void calculate_gas_information_new(struct dive *dive, struct plot_info *p
entry->pressures.n2 / amb_pressure * N2_DENSITY +
entry->pressures.he / amb_pressure * HE_DENSITY) /
(O2_IN_AIR * O2_DENSITY + N2_IN_AIR * N2_DENSITY) * 1000 - 10000;
entry->density = gas_density(&dive->cylinder[cylinderindex].gasmix, depth_to_mbar(entry->depth, dive));
if (entry->mod < 0)
entry->mod = 0;
if (entry->ead < 0)
@ -1292,7 +1293,7 @@ static void plot_string(struct plot_info *pi, struct plot_data *entry, struct me
{
int pressurevalue, mod, ead, end, eadd;
const char *depth_unit, *pressure_unit, *temp_unit, *vertical_speed_unit;
double depthvalue, tempvalue, speedvalue, sacvalue;
double depthvalue, tempvalue, speedvalue, sacvalue, density;
int decimals;
const char *unit;
@ -1327,15 +1328,18 @@ static void plot_string(struct plot_info *pi, struct plot_data *entry, struct me
put_format(b, translate("gettextFromC", "MOD: %d%s\n"), mod, depth_unit);
}
eadd = lrint(get_depth_units(lrint(entry->eadd), NULL, &depth_unit));
if (prefs.ead) {
switch (pi->dive_type) {
case NITROX:
ead = lrint(get_depth_units(lrint(entry->ead), NULL, &depth_unit));
put_format(b, translate("gettextFromC", "EAD: %d%s\nEADD: %d%s\n"), ead, depth_unit, eadd, depth_unit);
put_format(b, translate("gettextFromC", "density: %.1fg/l\n"), entry->density);
break;
case TRIMIX:
end = lrint(get_depth_units(lrint(entry->end), NULL, &depth_unit));
put_format(b, translate("gettextFromC", "END: %d%s\nEADD: %d%s\n"), end, depth_unit, eadd, depth_unit);
put_format(b, translate("gettextFromC", "density: %.1fg/l\n"), entry->density);
break;
case AIR:
case FREEDIVING:

1
core/profile.h
View file

@ -64,6 +64,7 @@ struct plot_data {
int bearing;
double ambpressure;
double gfline;
double density;
};
struct ev_select {

2
core/units.h
View file

@ -14,7 +14,7 @@ extern "C" {
#define O2_IN_AIR 209 // permille
#define N2_IN_AIR 781
#define O2_DENSITY 1429 // mg/Liter
#define N2_DENSITY 1251
#define N2_DENSITY 1165
#define HE_DENSITY 179
#define SURFACE_PRESSURE 1013 // mbar
#define SURFACE_PRESSURE_STRING "1013"