/*******************************************************************************
* This file is part of SWIFT.
* Copyright (c) 2019 Josh Borrow (joshua.borrow@durham.ac.uk)
*
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
******************************************************************************/
#ifndef SWIFT_GADGET2_HYDRO_PARAMETERS_H
#define SWIFT_GADGET2_HYDRO_PARAMETERS_H
/* Configuration file */
#include <config.h>
/* Global headers */
#if defined(HAVE_HDF5)
#include <hdf5.h>
#endif
/* Local headers */
#include "common_io.h"
#include "error.h"
#include "inline.h"
/**
* @file Gadget2/hydro_parameters.h
* @brief Follows the Gadget-2 version of SPH. (default parameters)
*
* This file defines a number of things that are used in
* hydro_properties.c as defaults for run-time parameters
* as well as a number of compile-time parameters.
*/
/* Viscosity parameters -- FIXED -- MUST BE DEFINED AT COMPILE-TIME */
/* Cosmology default beta=3.0.
* Alpha can be set in the parameter file.
* Beta is defined as in e.g. Price (2010) Eqn (103) */
#define const_viscosity_beta 3.0f
/* The viscosity that the particles are reset to after being hit by a
* feedback event. This should be set to the same value as the
* hydro_props_default_viscosity_alpha in fixed schemes, and likely
* to hydro_props_default_viscosity_alpha_max in variable schemes. */
#define hydro_props_default_viscosity_alpha_feedback_reset 0.8f
/* Viscosity paramaters -- Defaults; can be changed at run-time */
/* The "initial" hydro viscosity, or the fixed value for non-variable
* schemes. This usually takes the value 0.8. */
#define hydro_props_default_viscosity_alpha 0.8f
/* Structs that store the relevant variables */
/*! Artificial viscosity parameters */
struct viscosity_global_data {
/*! For the fixed, simple case. Also used to set the initial AV
coefficient for variable schemes. */
float alpha;
};
/*! Thermal diffusion parameters */
struct diffusion_global_data {};
/* Functions for reading from parameter file */
/* Forward declartions */
struct swift_params;
struct phys_const;
struct unit_system;
/* Viscosity */
/**
* @brief Initialises the viscosity parameters in the struct from
* the parameter file, or sets them to defaults.
*
* @param params: the pointer to the swift_params file
* @param us: pointer to the internal unit system
* @param phys_const: pointer to the physical constants system
* @param viscosity: pointer to the viscosity_global_data struct to be filled.
**/
static INLINE void viscosity_init(struct swift_params* params,
const struct unit_system* us,
const struct phys_const* phys_const,
struct viscosity_global_data* viscosity) {
/* Read the artificial viscosity parameters from the file, if they exist,
* otherwise set them to the defaults defined above. */
viscosity->alpha = parser_get_opt_param_float(
params, "SPH:viscosity_alpha", hydro_props_default_viscosity_alpha);
}
/**
* @brief Initialises a viscosity struct to sensible numbers for mocking
* purposes.
*
* @param viscosity: pointer to the viscosity_global_data struct to be filled.
**/
static INLINE void viscosity_init_no_hydro(
struct viscosity_global_data* viscosity) {
viscosity->alpha = hydro_props_default_viscosity_alpha;
}
/**
* @brief Prints out the viscosity parameters at the start of a run.
*
* @param viscosity: pointer to the viscosity_global_data struct found in
* hydro_properties
**/
static INLINE void viscosity_print(
const struct viscosity_global_data* viscosity) {
message("Artificial viscosity parameters set to alpha: %.3f",
viscosity->alpha);
}
#if defined(HAVE_HDF5)
/**
* @brief Prints the viscosity information to the snapshot when writing.
*
* @param h_grpsph: the SPH group in the ICs to write attributes to.
* @param viscosity: pointer to the viscosity_global_data struct.
**/
static INLINE void viscosity_print_snapshot(
hid_t h_grpsph, const struct viscosity_global_data* viscosity) {
io_write_attribute_f(h_grpsph, "Alpha viscosity", viscosity->alpha);
io_write_attribute_f(h_grpsph, "Beta viscosity", const_viscosity_beta);
}
#endif
/* Diffusion */
/**
* @brief Initialises the diffusion parameters in the struct from
* the parameter file, or sets them to defaults.
*
* @param params: the pointer to the swift_params file
* @param us: pointer to the internal unit system
* @param phys_const: pointer to the physical constants system
* @param diffusion: pointer to the diffusion struct to be filled.
**/
static INLINE void diffusion_init(struct swift_params* params,
const struct unit_system* us,
const struct phys_const* phys_const,
struct diffusion_global_data* diffusion) {}
/**
* @brief Initialises a diffusion struct to sensible numbers for mocking
* purposes.
*
* @param diffusion: pointer to the diffusion_global_data struct to be filled.
**/
static INLINE void diffusion_init_no_hydro(
struct diffusion_global_data* diffusion) {}
/**
* @brief Prints out the diffusion parameters at the start of a run.
*
* @param diffusion: pointer to the diffusion_global_data struct found in
* hydro_properties
**/
static INLINE void diffusion_print(
const struct diffusion_global_data* diffusion) {}
#ifdef HAVE_HDF5
/**
* @brief Prints the diffusion information to the snapshot when writing.
*
* @param h_grpsph: the SPH group in the ICs to write attributes to.
* @param diffusion: pointer to the diffusion_global_data struct.
**/
static INLINE void diffusion_print_snapshot(
hid_t h_grpsph, const struct diffusion_global_data* diffusion) {}
#endif
#endif /* SWIFT_GADGET2_HYDRO_PARAMETERS_H */