subsurface/core/gas.h
Berthold Stoeger 23da23a534 core: add N2 and general gas component accessors
There were helper functions to access O2 and He component fractions.
Add another one for N2. Indeed, this can be used in three cases, where
N2 was deduced indirectly.

Moreover, add a general accessor with a gas_component argument.
This will be used by the filter code to filter for gas components.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
2020-10-03 10:29:15 -07:00

65 lines
1.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
#ifndef GAS_H
#define GAS_H
#include "units.h"
#ifdef __cplusplus
extern "C" {
#else
#include <stdbool.h>
#endif
enum gas_component { N2, HE, O2 };
// o2 == 0 && he == 0 -> air
// o2 < 0 -> invalid
struct gasmix {
fraction_t o2;
fraction_t he;
};
static const struct gasmix gasmix_invalid = { { -1 }, { -1 } };
static const struct gasmix gasmix_air = { { 0 }, { 0 } };
struct icd_data { // This structure provides communication between function isobaric_counterdiffusion() and the calling software.
int dN2; // The change in fraction (permille) of nitrogen during the change
int dHe; // The change in fraction (permille) of helium during the change
};
extern bool isobaric_counterdiffusion(struct gasmix oldgasmix, struct gasmix newgasmix, struct icd_data *results);
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);
extern int same_gasmix(struct gasmix a, struct gasmix b);
static inline int get_o2(struct gasmix mix)
{
return mix.o2.permille ?: O2_IN_AIR;
}
static inline int get_he(struct gasmix mix)
{
return mix.he.permille;
}
static inline int get_n2(struct gasmix mix)
{
return 1000 - get_o2(mix) - get_he(mix);
}
struct gas_pressures {
double o2, n2, he;
};
extern void sanitize_gasmix(struct gasmix *mix);
extern int gasmix_distance(struct gasmix a, struct gasmix b);
extern fraction_t get_gas_component_fraction(struct gasmix mix, enum gas_component component);
extern bool gasmix_is_air(struct gasmix gasmix);
#ifdef __cplusplus
}
#endif
#endif