Inputs
The mdss package requires an yaml
file to configure and execute simulations.
YAML Configuration File
A YAML file is required to define the simulation parameters and organize test cases. The YAML file structure and respective descriptions are given below.
Input YAML file Structure
The YAML file organizes simulation data into a structured hierarchy, enabling clear configuration of cases and experimental conditions. Below is the structure used in the YAML file:
out_dir: # str, path to the output directory
python_version: /usr/bin/python # Optional[str], path to the python env to use
machine_type: local # str, local/hpc
nproc: 8 # int, number of processors, required when machine_type is local
######################################################################################
# `hpc_info` is required only if machine_type is hpc
######################################################################################
hpc_info: # dict, required only if machine_type is hpc
cluster: GL # str, name of the cluster. GL for Great Lakes
job_name: example # str, name of the job
account_name: test_account # str, account name
partition: standard # str, partition name
time: 01:00:00 # str, time in D-H:M:S format
nodes: 1 # int, number of nodes
nproc: 10 # int, total number of processors
nproc_per_node: 10 # int, number of processors per node
mem_per_cpu: 1000mb # Optional[str], memory per cpu
mail_types: NONE # Optional[str], mail types
email_id: example@test.com # Optional[str], email id
hierarchies: # list[dict], List of hierarchies
# First hierarchy
- name: first_hierarchy # str, name of the hierarchy
cases: # list[dict], list of cases in this hierarchy
# First case in the hierarchy
- name: first_case # str, name of the case
meshes_folder_path: grids/ # str, path to the folder containing the mesh files for this case
mesh_files: # list[str], list of mesh file names
- mesh_L0.cgns # str, name of the first mesh file
- mesh_L1.cgns # str, name of the second mesh file
geometry_info: # dict, dictionary of geometry info
chordRef: 1.0 # float, reference chord length
areaRef: 1.0 # float, reference area
aero_options: # Optional[dict], dictionary of ADflow solver parameters. For more information see aero options section
# ......
scenarios: # list[dict], list of dictionaries containing scenario info
# First experimental set in current case
- name: cruise # str, name of the scenario
aoa_list: # list[float], list of angle of attacks(AoA) to run in with the experimental info
- 0.0
- 2.0
reynolds: 9.0e6 # float, Reynold's number
mach: 0.2 # float, Mach number
Temp: 298 # float, Temperature in Kelvin scale
exp_data: exp_data/first_case.csv # str, path to experimental data
# Second scenario in current case
######################################################################################
# The following structural options are required only for Aero-structural problems
######################################################################################
struct_options: # dict, structural options,
isym: 1 # int, direction of symmetry. 1 for y-symmetry, 2 for z-symmetry
t: 0.005 # float, Shell Thickness in m
mesh_fpath: /path/to/structural/mesh # str, path to the structural mesh file
struct_properties: # Optional[dict], a dictionary containing structural properties
rho: 2500.0 # Optional[float], Density in kg/m^3
E: 70.0e9 # Optional[float], Young's modulus in N/m^2
nu: 0.30 # Optional[float], Poisson's ratio
kcorr: 0.83333 # Optional[float}, Shear correction factor
ys: 350.0e6 # Optional[float], Yield stress in N/m^2
load_info: # Optional[dict], a dictionary containing load info
g: [0.0, -9.81, 0.0] # Optional[list[float]], g-vector in m/s^2, the default is [0, -9.81, 0]
inertial_load_factor: 1.0 # optional[float], times of 'g'.
solver_options: # Optional[dict], solver options for coupling. Check solver options section for more info
linear_solver_options: # Optional[dict], linear solver options, see documentation for more info.
nonlinear_solver_options: # Optional[dict], nonlinear solver options, see documentation for more info.
# Second case in current hierarchy
# Second hierarchy
Please note that adherence to this structure is essential; any deviation
may lead to errors when running simulations. Examples of correctly
formatted YAML files are provided in the examples/inputs folder.
These yaml script can also be used as a starting point for generating custom YAML files.
Aero Options
aero_options is a dictionary containing options specific to the
ADflow CFD solver, allowing users to customize the solver’s behavior to
suit their simulation needs. Detailed descriptions of these parameters
and their usage can be found in the ADflow
Documentation.
If the dictionary is empty or if the default parameters are not modified, the code will use a predefined set of default solver options. These defaults are designed to provide a reliable baseline configuration for running simulations effectively without requiring manual adjustments.
Default aero_options for aerodynamic problem
# Print Options
"printIterations": False,
"printAllOptions": False,
"printIntro": False,
"printTiming": False,
# I/O Parameters
"outputDirectory": ".",
"monitorvariables": ["resrho", "resturb", "cl", "cd", "yplus"],
"writeTecplotSurfaceSolution": True,
"solutionPrecision": "double", # Best for restart
"volumeVariables": ['resrho', 'mach'],
# Physics Parameters
"equationType": "RANS",
"liftindex": 3, # z is the lift direction
# Solver Parameters
"smoother": "DADI",
"CFL": 0.5,
"CFLCoarse": 0.25,
"MGCycle": "sg",
"MGStartLevel": -1,
"nCyclesCoarse": 250,
# ANK Solver Parameters
"useANKSolver": True,
"nSubiterTurb": 5,
# Termination Criteria
"L2Convergence": 1e-12,
"L2ConvergenceCoarse": 1e-2,
"nCycles": 75000,
Default aero_options for aerostructural problems
# Print Options
"printIterations": False,
"printAllOptions": False,
"printIntro": False,
"printTiming": False,
# I/O Parameters
"outputDirectory": '.',
"monitorvariables": ["resrho", "resturb", "cl", "cd", "yplus"],
"writeTecplotSurfaceSolution": True,
# Physics Parameters
"equationType": "RANS",
"liftindex": 3, # z is the lift direction
# Solver Parameters
"smoother": "DADI",
"CFL": 1.5,
"CFLCoarse": 1.25,
"MGCycle": "sg",
"MGStartLevel": -1,
"nCyclesCoarse": 250,
# ANK Solver Parameters
"useANKSolver": True,
"nSubiterTurb": 5,
# Termination Criteria
"L2Convergence": 1e-12,
"L2ConvergenceCoarse": 1e-2,
"L2ConvergenceRel": 1e-3,
"nCycles": 10000,
# force integration
"forcesAsTractions": False,
Scenarios
To define the problem, referred to as the AeroProblem (focused on aerodynamics), flight conditions along with the name and a list of Angle of Attacks(AoA) is required, and path to the experimental data is optional.
Check
mdolab-baseclasses
for valid combinations flight conditions.The other properties will be
calculated automatically by mdolab-baseclasses based on the
specified values and the governing gas laws.
Location of Mesh Files
Specifying the location of the mesh files requires two inputs in every case:
meshes_folder_pathgets the path to the folder that contains the mesh filesmesh_filesgets the list of file names, that to be run, in the folder specified above.
Solver Options
solver_options is a dictionary containing options for
NonlinearBlockGS and LinearBlockGS solvers available in
openMDAO. If these are not provided, the default options will be
used. For more more information on these solvers visit the openMDAO
documentation
Default solver_options
"linear_solver_options":
"atol": 1e-08, # absolute error tolerance
"err_on_non_converge": True, # When True, AnalysisError will be raised if not converged
"maxiter": 25, # maximum number of iterations
"rtol": 1e-8, # relative error tolerance
"use_aitken": True, # set to True to use Aitken
"nonlinear_solver_options":
"atol": 1e-08, # absolute error tolerance
"err_on_non_converge": True, # When True, AnalysisError will be raised if not converged
"reraise_child_analysiserror": False, # When the option is true, a solver will raise any AnalysisError that arises during sub-solve; when false, it will continue solving.
"maxiter": 25, # maximum number of iterations
"rtol": 1e-08, # relative error tolerance
"use_aitken": True, # set to True to use Aitken