PICurv 0.1.0
A Parallel Particle-In-Cell Solver for Curvilinear LES
Loading...
Searching...
No Matches
Functions
ParticlePhysics.h File Reference

Header file for Particle related physics modules. More...

#include <petsc.h>
#include <petscdmswarm.h>
#include <stdbool.h>
#include <petscsys.h>
#include <math.h>
#include "variables.h"
#include "logging.h"
#include "walkingsearch.h"
Include dependency graph for ParticlePhysics.h:
This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Functions

PetscErrorCode UpdateParticleField (const char *fieldName, PetscReal dt, PetscReal *psi_io, PetscReal diffusivity, PetscReal mean_val, PetscReal cell_vol, PetscReal C_model)
 Updates a single particle's field based on its state and the specified field name.
 
PetscErrorCode UpdateFieldForAllParticles (UserCtx *user, const char *fieldName)
 Loops over all local particles and updates a specified field.
 
PetscErrorCode UpdateAllParticleFields (UserCtx *user)
 Orchestrates the update of all physical properties for particles.
 

Detailed Description

Header file for Particle related physics modules.

This file contains declarations of functions responsible for solving for fields in the particle swarms within a simulation using PETSc's DMSwarm.

Definition in file ParticlePhysics.h.

Function Documentation

◆ UpdateParticleField()

PetscErrorCode UpdateParticleField ( const char *  fieldName,
PetscReal  dt,
PetscReal *  psi_io,
PetscReal  diffusivity,
PetscReal  mean_val,
PetscReal  cell_vol,
PetscReal  C_model 
)

Updates a single particle's field based on its state and the specified field name.

This function serves as a switchboard for various particle property calculations. Given a particle's data, it computes a new value for the specified field.

Currently supported fields:

  • "Psi": Calculates the particle's kinetic energy (0.5 * |v|^2).
Parameters
[in]fieldNameThe name of the field to update (e.g., "Psi").
[in]tThe current simulation time.
[in]posThe particle's physical position.
[in]velThe particle's velocity.
[in,out]psi_ioA pointer to the particle's current Psi value (used for accumulation if needed).
Returns
PetscErrorCode 0 on success.

Updates a single particle's field based on its state and physics model.

Implements the IEM (Interaction by Exchange with the Mean) model for scalar mixing.

Physics: dPsi/dt = -Omega * (Psi - <Psi>) Solution: Psi_new = <Psi> + (Psi_old - <Psi>) * exp(-Omega * dt)

Parameters
[in]fieldNameName of the field (e.g., "Psi").
[in]dtTime step size.
[in,out]psi_ioPointer to the particle's scalar value (Psi).
[in]diffusivityParticle diffusivity (Gamma + Gamma_t).
[in]mean_valLocal Eulerian mean value (<Psi>).
[in]cell_volVolume of the host cell (1/Jacobian).
[in]C_modelModel constant (C_IEM).

Updates a single particle's field based on its state and the specified field name.

Implements the IEM (Interaction by Exchange with the Mean) model for scalar mixing.

Physics: dPsi/dt = -Omega * (Psi - <Psi>) Solution: Psi_new = <Psi> + (Psi_old - <Psi>) * exp(-Omega * dt)

Parameters
[in]fieldNameName of the field (e.g., "Psi").
[in]dtTime step size.
[in,out]psi_ioPointer to the particle's scalar value (Psi).
[in]diffusivityParticle diffusivity (Gamma + Gamma_t).
[in]mean_valLocal Eulerian mean value (<Psi>).
[in]cell_volVolume of the host cell (1/Jacobian).
[in]C_modelModel constant (C_IEM).

Definition at line 25 of file ParticlePhysics.c.

32{
33 PetscFunctionBeginUser;
34
35 if (strcmp(fieldName, "Psi") == 0) {
36 // --- IEM Mixing Model ---
37
38 // 1. Calculate Characteristic Length Scale (Delta)
39 // Delta^2 approx Volume^(2/3)
40 // Safety: Ensure volume is positive
41 if (cell_vol < 1.0e-14) cell_vol = 1.0e-14;
42
43 PetscReal delta2 = PetscPowReal(cell_vol, 0.6666667);
44
45 // 2. Calculate Mixing Frequency (Omega)
46 // Omega = C_phi * (Gamma_eff) / Delta^2
47 PetscReal omega = C_model * diffusivity / delta2;
48
49 // 3. Analytical Integration
50 // Exact solution for linear decay ODE
51 PetscReal decay = PetscExpReal(-omega * dt);
52
53 // Update Value IN-PLACE
54 PetscReal psi_old = *psi_io;
55 *psi_io = mean_val + (psi_old - mean_val) * decay;
56 }
57 else {
58 // Logic for other fields can be added here
59 // e.g. Temperature might use a different C_model or source term
60 }
61
62 PetscFunctionReturn(0);
63}
Here is the caller graph for this function:

◆ UpdateFieldForAllParticles()

PetscErrorCode UpdateFieldForAllParticles ( UserCtx *  user,
const char *  fieldName 
)

Loops over all local particles and updates a specified field.

This function orchestrates the update of a single particle field across the entire local swarm. It gets access to the necessary particle data arrays and calls the UpdateParticleField kernel for each particle.

Parameters
[in,out]userPointer to the UserCtx containing the swarm and simulation context.
[in]fieldNameThe name of the field to update (e.g., "Psi").
Returns
PetscErrorCode 0 on success.

Prepares necessary Eulerian and Lagrangian data structures before looping.

Parameters
[in,out]userPointer to the UserCtx.
[in]fieldNameThe name of the field to update (e.g., "Psi").
Returns
PetscErrorCode 0 on success.

Definition at line 76 of file ParticlePhysics.c.

77{
78 PetscErrorCode ierr;
79 DM swarm = user->swarm;
80 DM da = user->da; // Scalar DM for accessing lPsi and lAj
81 PetscInt n_local;
82 PetscReal dt = user->simCtx->dt;
83
84 // Model Constant (Default to 2.0 if not set)
85 PetscReal C_IEM = 2.0;//(user->simCtx->C_IEM > 1.0e-6) ? user->simCtx->C_IEM : 2.0;
86
87 // Pointers for Swarm Data
88 PetscReal *psi_arr = NULL;
89 PetscReal *diff_arr = NULL;
90 PetscInt *cell_arr = NULL;
91
92 // Pointers for Eulerian Data (Read-Only)
93 PetscReal ***grid_mean = NULL;
94 PetscReal ***grid_aj = NULL;
95
96 // Flags to track what we accessed (for cleanup)
97 PetscBool accessed_eulerian = PETSC_FALSE;
98
99 PetscFunctionBeginUser;
100 PROFILE_FUNCTION_BEGIN;
101
102 ierr = DMSwarmGetLocalSize(swarm, &n_local); CHKERRQ(ierr);
103 if (n_local == 0) {
104 PetscFunctionReturn(0);
105 }
106
107 // 1. Access Target Field (Write Access)
108 ierr = DMSwarmGetField(swarm, fieldName, NULL, NULL, (void**)&psi_arr); CHKERRQ(ierr);
109
110 // 2. Access Auxiliary Data based on Physics Requirements
111 // For "Psi", we need Diffusivity, CellID, Grid Mean, and Grid Metrics.
112 if (strcmp(fieldName, "Psi") == 0) {
113
114 // --- Lagrangian Data ---
115 ierr = DMSwarmGetField(swarm, "Diffusivity", NULL, NULL, (void**)&diff_arr); CHKERRQ(ierr);
116 ierr = DMSwarmGetField(swarm, "DMSwarm_CellID", NULL, NULL, (void**)&cell_arr); CHKERRQ(ierr);
117
118 // --- Eulerian Data ---
119 // We need Local vectors (lPsi, lAj) to handle ghost indexing safely
120 if (!user->lPsi || !user->lAj) {
121 SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "UserCtx lPsi or lAj not initialized.");
122 }
123
124 ierr = DMDAVecGetArrayRead(da, user->lPsi, &grid_mean); CHKERRQ(ierr);
125 ierr = DMDAVecGetArrayRead(da, user->lAj, &grid_aj); CHKERRQ(ierr);
126 accessed_eulerian = PETSC_TRUE;
127 }
128
129 // 3. Loop over particles
130 for (PetscInt p = 0; p < n_local; ++p) {
131
132 // Default values for generic fields
133 PetscReal p_diff = 0.0;
134 PetscReal p_mean = 0.0;
135 PetscReal p_vol = 1.0;
136
137 if (strcmp(fieldName, "Psi") == 0) {
138 // Unpack indices
139 PetscInt i = cell_arr[3*p + 0];
140 PetscInt j = cell_arr[3*p + 1];
141 PetscInt k = cell_arr[3*p + 2];
142
143 // Fetch Data
144 p_diff = diff_arr[p];
145 p_mean = grid_mean[k][j][i]; // Direct Lookup
146
147 // Calculate Volume = 1.0 / Jacobian
148 PetscReal jac = grid_aj[k][j][i];
149 p_vol = (jac > 1.0e-14) ? (1.0 / jac) : 1.0e-14;
150 }
151
152 // Call Kernel
153 ierr = UpdateParticleField(fieldName, dt, &psi_arr[p], p_diff, p_mean, p_vol, C_IEM);
154 CHKERRQ(ierr);
155 }
156
157 // 4. Restore Arrays
158 ierr = DMSwarmRestoreField(swarm, fieldName, NULL, NULL, (void**)&psi_arr); CHKERRQ(ierr);
159
160 if (strcmp(fieldName, "Psi") == 0) {
161 ierr = DMSwarmRestoreField(swarm, "Diffusivity", NULL, NULL, (void**)&diff_arr); CHKERRQ(ierr);
162 ierr = DMSwarmRestoreField(swarm, "DMSwarm_CellID", NULL, NULL, (void**)&cell_arr); CHKERRQ(ierr);
163 }
164
165 if (accessed_eulerian) {
166 ierr = DMDAVecRestoreArrayRead(da, user->lPsi, &grid_mean); CHKERRQ(ierr);
167 ierr = DMDAVecRestoreArrayRead(da, user->lAj, &grid_aj); CHKERRQ(ierr);
168 }
169
170 LOG_ALLOW(GLOBAL, LOG_INFO, "Updated particle physics for field '%s'.\n", fieldName);
171
172 PROFILE_FUNCTION_END;
173 PetscFunctionReturn(0);
174}
UpdateParticleField
PetscErrorCode UpdateParticleField(const char *fieldName, PetscReal dt, PetscReal *psi_io, PetscReal diffusivity, PetscReal mean_val, PetscReal cell_vol, PetscReal C_model)
Updates a single particle's field based on its state and physics model.
Definition ParticlePhysics.c:25
GLOBAL
#define GLOBAL
Scope for global logging across all processes.
Definition logging.h:46
LOG_ALLOW
#define LOG_ALLOW(scope, level, fmt,...)
Logging macro that checks both the log level and whether the calling function is in the allowed-funct...
Definition logging.h:200
PROFILE_FUNCTION_END
#define PROFILE_FUNCTION_END
Marks the end of a profiled code block.
Definition logging.h:746
LOG_INFO
@ LOG_INFO
Informational messages about program execution.
Definition logging.h:31
PROFILE_FUNCTION_BEGIN
#define PROFILE_FUNCTION_BEGIN
Marks the beginning of a profiled code block (typically a function).
Definition logging.h:737
UserCtx::simCtx
SimCtx * simCtx
Back-pointer to the master simulation context.
Definition variables.h:731
SimCtx::dt
PetscReal dt
Definition variables.h:599
UserCtx::lPsi
Vec lPsi
Definition variables.h:801
UserCtx::lAj
Vec lAj
Definition variables.h:776
Here is the call graph for this function:
Here is the caller graph for this function:

◆ UpdateAllParticleFields()

PetscErrorCode UpdateAllParticleFields ( UserCtx *  user)

Orchestrates the update of all physical properties for particles.

This function serves as the top-level entry point for updating particle-specific physical quantities after their position and the surrounding fluid velocity are known. It calls a sequence of more specific update routines for each property.

For example, it can be configured to update:

Parameters
[in,out]userPointer to the UserCtx containing the swarm and simulation context.
Returns
PetscErrorCode 0 on success.

Definition at line 178 of file ParticlePhysics.c.

179{
180 PetscErrorCode ierr;
181 PetscFunctionBeginUser;
182 PROFILE_FUNCTION_BEGIN;
183
184 LOG_ALLOW(GLOBAL, LOG_INFO, "Updating all particle physical properties...\n");
185
186 // Update Scalar Mixing (IEM)
187 // IMPORTANT: Ensure ScatterParticleFieldToEulerField("Psi") has been called
188 // immediately before this to populate user->lPsi with the current mean.
189 ierr = UpdateFieldForAllParticles(user, "Psi"); CHKERRQ(ierr);
190
191 LOG_ALLOW(GLOBAL, LOG_INFO, "All particle physical properties updated.\n");
192
193 PROFILE_FUNCTION_END;
194 PetscFunctionReturn(0);
195}
UpdateFieldForAllParticles
PetscErrorCode UpdateFieldForAllParticles(UserCtx *user, const char *fieldName)
Loops over all local particles and updates a specified field.
Definition ParticlePhysics.c:76
Here is the call graph for this function:
Here is the caller graph for this function: