/*******************************************************************************
* 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_SPHENIX_HYDRO_PARAMETERS_H
#define SWIFT_SPHENIX_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 SPHENIX/hydro_parameters.h
* @brief Density-Energy conservative implementation of SPH,
* with added SPHENIX physics (Borrow 2020) (default compile-time
* 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 2.0f
/* 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 0.1f
/*! Minimal value for the viscosity alpha in variable schemes. */
#define hydro_props_default_viscosity_alpha_min 0.0f
/*! Maximal value for the viscosity alpha in variable schemes. */
#define hydro_props_default_viscosity_alpha_max 2.0f
/*! Decay length for the viscosity scheme. This is scheme dependent. */
#define hydro_props_default_viscosity_length 0.05f
/* Diffusion parameters -- FIXED -- MUST BE DEFINED AT COMPILE-TIME */
/*! The diffusion 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_diffusion_alpha in fixed schemes, and likely
* to hydro_props_default_diffusion_alpha_min in variable schemes. */
#define hydro_props_default_diffusion_alpha_feedback_reset 0.0f
/* Diffusion parameters -- Defaults; can be changed at run-time */
/*! The "initial" diffusion, or the fixed value for non-variable
* schemes. This usually takes the value 0.0. */
#define hydro_props_default_diffusion_alpha 0.0f
/*! Beta coefficient for the diffusion. This controls how fast the
* diffusion coefficient peaks, and how high it can get. Chosen to be
* very small in schemes where little diffusion is needed, 0.2-1.0 in
* schemes (e.g. density-energy) where diffusion is needed to solve
* the contact discontinuity problem. */
#define hydro_props_default_diffusion_beta 1.0f
/*! Maximal value for the diffusion alpha in variable schemes. */
#define hydro_props_default_diffusion_alpha_max 1.0f
/*! Minimal value for the diffusion alpha in variable schemes. */
#define hydro_props_default_diffusion_alpha_min 0.0f
/* 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;
/*! Artificial viscosity (max) for the variable case (e.g. M&M) */
float alpha_max;
/*! Artificial viscosity (min) for the variable case (e.g. M&M) */
float alpha_min;
/*! The decay length of the artificial viscosity (used in M&M, etc.) */
float length;
};
/*! Thermal diffusion parameters */
struct diffusion_global_data {
/*! Initialisation value, or the case for constant thermal diffusion coeffs
*/
float alpha;
/*! Tuning parameter for speed of ramp up/down */
float beta;
/*! Maximal value for alpha_diff */
float alpha_max;
/*! Minimal value for alpha_diff */
float alpha_min;
};
/* 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 unit_system: pointer to the 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);
viscosity->alpha_max =
parser_get_opt_param_float(params, "SPH:viscosity_alpha_max",
hydro_props_default_viscosity_alpha_max);
viscosity->alpha_min =
parser_get_opt_param_float(params, "SPH:viscosity_alpha_min",
hydro_props_default_viscosity_alpha_min);
viscosity->length = parser_get_opt_param_float(
params, "SPH:viscosity_length", hydro_props_default_viscosity_length);
}
/**
* @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;
viscosity->alpha_max = hydro_props_default_viscosity_alpha_max;
viscosity->alpha_min = hydro_props_default_viscosity_alpha_min;
viscosity->length = hydro_props_default_viscosity_length;
}
/**
* @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, max: %.3f, "
"min: %.3f, length: %.3f.",
viscosity->alpha, viscosity->alpha_max, viscosity->alpha_min,
viscosity->length);
}
#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, "Alpha viscosity (max)", viscosity->alpha_max);
io_write_attribute_f(h_grpsph, "Alpha viscosity (min)", viscosity->alpha_min);
io_write_attribute_f(h_grpsph, "Viscosity decay length [internal units]",
viscosity->length);
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 unit_system: pointer to the unit system
* @param phys_const: pointer to the physical constants system
* @param diffusion_global_data: 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) {
diffusion->alpha = parser_get_opt_param_float(
params, "SPH:diffusion_alpha", hydro_props_default_diffusion_alpha);
diffusion->beta = parser_get_opt_param_float(
params, "SPH:diffusion_beta", hydro_props_default_diffusion_beta);
diffusion->alpha_max =
parser_get_opt_param_float(params, "SPH:diffusion_alpha_max",
hydro_props_default_diffusion_alpha_max);
diffusion->alpha_min =
parser_get_opt_param_float(params, "SPH:diffusion_alpha_min",
hydro_props_default_diffusion_alpha_min);
}
/**
* @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) {
diffusion->alpha = hydro_props_default_diffusion_alpha;
diffusion->alpha_max = hydro_props_default_diffusion_alpha_max;
diffusion->alpha_min = hydro_props_default_diffusion_alpha_min;
diffusion->beta = hydro_props_default_diffusion_beta;
}
/**
* @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) {
message(
"Artificial diffusion parameters set to alpha: %.3f, max: %.3f, "
"min: %.3f, beta: %.3f.",
diffusion->alpha, diffusion->alpha_max, diffusion->alpha_min,
diffusion->beta);
}
#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) {
io_write_attribute_f(h_grpsph, "Diffusion alpha", diffusion->alpha);
io_write_attribute_f(h_grpsph, "Diffusion alpha (max)", diffusion->alpha_max);
io_write_attribute_f(h_grpsph, "Diffusion alpha (min)", diffusion->alpha_min);
io_write_attribute_f(h_grpsph, "Diffusion beta", diffusion->beta);
}
#endif
#endif /* SWIFT_SPHENIX_HYDRO_PARAMETERS_H */