1# Runtime options 2 3## Common Options 4The Navier-Stokes HONEE app is controlled via command-line options. 5The following options are common among all problem types: 6 7:::{list-table} Common Runtime Options 8:header-rows: 1 9 10* - Option 11 - Description 12 - Default value 13 14* - `-ceed` 15 - CEED resource specifier 16 - `/cpu/self/opt/blocked` 17 18* - `-problem` 19 - Problem to solve (`advection`, `density_current`, `euler_vortex`, `shocktube`, `blasius`, `channel`, `gaussian_wave`, and `taylor_green`) 20 - `density_current` 21 22* - `-implicit` 23 - Use implicit time integrator formulation 24 - 25 26* - `-degree` 27 - Polynomial degree of tensor product basis (must be >= 1) 28 - `1` 29 30* - `-q_extra` 31 - Number of extra quadrature points 32 - `0` 33 34* - `-ts_monitor_solution` 35 - PETSc output format, such as `cgns:output-%d.cgns` (requires PETSc `--download-cgns`) 36 - 37 38* - `-ts_monitor_solution_interval` 39 - Number of time steps between visualization output frames. 40 - `1` 41 42* - `-viewer_cgns_batch_size` 43 - Number of frames written per CGNS file if the CGNS file name includes a format specifier (`%d`). 44 - `20` 45 46* - `-checkpoint_interval` 47 - Number of steps between writing binary checkpoints. `0` has no output, `-1` outputs final state only 48 - `10` 49 50* - `-checkpoint_vtk` 51 - Checkpoints include VTK (`*.vtu`) files for visualization. Consider `-ts_monitor_solution`instead. 52 - `false` 53 54* - `-viz_refine` 55 - Use regular refinement for VTK visualization 56 - `0` 57 58* - `-output_dir` 59 - Output directory for binary checkpoints and VTK files (if enabled). 60 - `.` 61 62* - `-output_add_stepnum2bin` 63 - Whether to add step numbers to output binary files 64 - `false` 65 66* - `-continue` 67 - Continue from previous solution (input is step number of previous solution) 68 - `0` 69 70* - `-continue_filename` 71 - Path to file from which to continue from 72 - 73 74* - `-bc_wall` 75 - Use wall boundary conditions on this list of faces 76 - 77 78* - `-wall_comps` 79 - An array of constrained component numbers for wall BCs 80 - 81 82* - `-bc_slip` 83 - Use weak slip boundary condition on this list of faces 84 - 85 86* - `-bc_symmetry_x` 87 - Use symmetry boundary conditions, for the x component, on this list of faces 88 - 89 90* - `-bc_symmetry_y` 91 - Use symmetry boundary conditions, for the y component, on this list of faces 92 - 93 94* - `-bc_symmetry_z` 95 - Use symmetry boundary conditions, for the z component, on this list of faces 96 - 97 98* - `-bc_inflow` 99 - Use inflow boundary conditions on this list of faces 100 - 101 102* - `-bc_outflow` 103 - Use outflow boundary conditions on this list of faces 104 - 105 106* - `-bc_freestream` 107 - Use freestream boundary conditions on this list of faces 108 - 109 110* - `-ts_monitor_turbulence_spanstats_collect_interval` 111 - Number of timesteps between statistics collection 112 - `1` 113 114* - `-ts_monitor_turbulence_spanstats_viewer` 115 - Sets the PetscViewer for the statistics file writing, such as `cgns:output-%d.cgns` (requires PETSc `--download-cgns`). Also turns the statistics collection on. 116 - 117 118* - `-ts_monitor_turbulence_spanstats_viewer_interval` 119 - Number of timesteps between statistics file writing (`-1` means only at end of run) 120 - `-1` 121 122* - `-ts_monitor_turbulence_spanstats_viewer_cgns_batch_size` 123 - Number of frames written per CGNS file if the CGNS file name includes a format specifier (`%d`). 124 - `20` 125 126* - `-ts_monitor_wall_force` 127 - Viewer for the force on each no-slip wall, e.g., `ascii:force.csv:ascii_csv` to write a CSV file. 128 - 129 130* - `-mesh_transform` 131 - Transform the mesh, usually for an initial box mesh. 132 - `none` 133 134* - `-snes_view` 135 - View PETSc `SNES` nonlinear solver configuration 136 - 137 138* - `-log_view` 139 - View PETSc performance log 140 - 141 142* - `-help` 143 - View comprehensive information about run-time options 144 - 145 146* - `-test_type` 147 - Run in test mode and specify whether solution (`solver`) or turbulent statistics (`turb_spanstats`) output should be verified 148 - `none` 149 150* - `-compare_final_state_atol` 151 - Test absolute tolerance 152 - `1E-11` 153 154* - `-compare_final_state_filename` 155 - Test filename 156 - 157 158::: 159 160For the case of a square/cubic mesh, the list of face indices to be used with `-bc_wall`, `bc_inflow`, `bc_outflow`, `bc_freestream` and/or `-bc_symmetry_x`, `-bc_symmetry_y`, and `-bc_symmetry_z` are: 161 162:::{list-table} 2D Face ID Labels 163:header-rows: 1 164* - PETSc Face Name 165 - Cartesian direction 166 - Face ID 167 168* - faceMarkerBottom 169 - -z 170 - 1 171 172* - faceMarkerRight 173 - +x 174 - 2 175 176* - faceMarkerTop 177 - +z 178 - 3 179 180* - faceMarkerLeft 181 - -x 182 - 4 183::: 184 185:::{list-table} 3D Face ID Labels 186:header-rows: 1 187* - PETSc Face Name 188 - Cartesian direction 189 - Face ID 190 191* - faceMarkerBottom 192 - -z 193 - 1 194 195* - faceMarkerTop 196 - +z 197 - 2 198 199* - faceMarkerFront 200 - -y 201 - 3 202 203* - faceMarkerBack 204 - +y 205 - 4 206 207* - faceMarkerRight 208 - +x 209 - 5 210 211* - faceMarkerLeft 212 - -x 213 - 6 214::: 215 216## Boundary conditions 217 218Boundary conditions for compressible viscous flows are notoriously tricky. 219Here we offer some recommendations. 220 221### Inflow 222 223If in a region where the flow velocity is known (e.g., away from viscous walls), use `bc_freestream`, which solves a Riemann problem and can handle inflow and outflow (simultaneously and dynamically). 224It is stable and the least reflective boundary condition for acoustics. 225 226If near a viscous wall, you may want a specified inflow profile. 227Use `bc_inflow` and see {ref}`example-blasius` and discussion of synthetic turbulence generation for ways to analytically generate developed inflow profiles. 228These conditions may be either weak or strong, with the latter specifying velocity and temperature as essential boundary conditions and evaluating a boundary integral for the mass flux. 229The strong approach gives sharper resolution of velocity structures. 230We have described the primitive variable formulation here; the conservative variants are similar, but not equivalent. 231 232### Outflow 233 234If you know the complete exterior state, `bc_freestream` is the least reflective boundary condition, but is disruptive to viscous flow structures. 235If thermal anomalies must exit the domain, the Riemann solver must resolve the contact wave to avoid reflections. 236The default Riemann solver, HLLC, is sufficient in this regard while the simpler HLL converts thermal structures exiting the domain into grid-scale reflecting acoustics. 237 238If acoustic reflections are not a concern and/or the flow is impacted by walls or interior structures that you wish to resolve to near the boundary, choose `bc_outflow`. This condition (with default `outflow_type: riemann`) is stable for both inflow and outflow, so can be used in areas that have recirculation and lateral boundaries in which the flow fluctuates. 239 240The simpler `bc_outflow` variant, `outflow_type: pressure`, requires that the flow be a strict outflow (or the problem becomes ill-posed and the solver will diverge). 241In our experience, `riemann` is slightly less reflective but produces similar flows in cases of strict outflow. 242The `pressure` variant is retained to facilitate comparison with other codes, such as PHASTA-C, but we recommend `riemann` for general use. 243 244### Periodicity 245 246PETSc provides two ways to specify periodicity: 247 2481. Topological periodicity, in which the donor and receiver dofs are the same, obtained using: 249 250```yaml 251dm_plex: 252 shape: box 253 box_faces: 10,12,4 254 box_bd: none,none,periodic 255``` 256 257The coordinates for such cases are stored as a new field with special cell-based indexing to enable wrapping through the boundary. 258This choice of coordinates prevents evaluating boundary integrals that cross the periodicity, such as for the outflow Riemann problem in the presence of spanwise periodicity. 259 2602. Isoperiodicity, in which the donor and receiver dofs are distinct in local vectors. This is obtained using `zbox`, as in: 261 262```yaml 263dm_plex: 264 shape: zbox 265 box_faces: 10,12,4 266 box_bd: none,none,periodic 267``` 268 269Isoperiodicity enables standard boundary integrals, and is recommended for general use. 270At the time of this writing, it only supports one direction of periodicity. 271The `zbox` method uses [Z-ordering](https://en.wikipedia.org/wiki/Z-order_curve) to construct the mesh in parallel and provide an adequate initial partition, which makes it higher performance and avoids needing a partitioning package. 272 273## Advection-Diffusion 274 275There is a reduced mode for pure advection, which holds density $\rho$ and momentum density $\rho \bm u$ constant while advecting "total energy density" $E$. 276The advection problems can be run in both 2D and 3D, based on the DM defined for the problem. 277The following additional command-line options are available: 278 279:::{list-table} Advection Runtime Options 280:header-rows: 1 281 282* - Option 283 - Description 284 - Default value 285 - Unit 286 287* - `-units_meter` 288 - 1 meter in scaled length units 289 - `1E-2` 290 - 291 292* - `-units_second` 293 - 1 second in scaled time units 294 - `1E-2` 295 - 296 297* - `-units_kilogram` 298 - 1 kilogram in scaled mass units 299 - `1E-6` 300 - 301 302* - `-strong_form` 303 - Strong (1) or weak/integrated by parts (0) residual 304 - `0` 305 - 306 307* - `-stab` 308 - Stabilization method (`none`, `su`, or `supg`) 309 - `none` 310 - 311 312* - `-stab_tau` 313 - Formulation for $\tau$ in stabilization (`ctau`, `advdiff_shakib`) 314 - `ctau` 315 - 316 317* - `-Ctau_t` 318 - Scaling factor on the temporal portion of the $\tau$ formulation 319 - 0. 320 - 321 322* - `-Ctau_a` 323 - Scaling factor on the advection portion of the $\tau$ formulation 324 - $P^2$ 325 - 326 327* - `-Ctau_d` 328 - Scaling factor on the diffusion portion of the $\tau$ formulation 329 - $P^4$ 330 - 331 332* - `-CtauS` 333 - Scale coefficient for stabilization tau (nondimensional) 334 - `0` 335 - 336 337* - `-wind_type` 338 - Wind type in Advection (`rotation`, `translation`, `boundary_layer`) 339 - `rotation` 340 - 341 342* - `-wind_translation` 343 - Constant wind vector when `-wind_type translation` 344 - `1,0,0` 345 - 346 347* - `-diffusion_coeff` 348 - Diffusion coefficient 349 - `0` 350 - 351 352* - `-E_wind` 353 - Total energy of inflow wind when `-wind_type translation` 354 - `1E6` 355 - `J` 356 357* - `-advection_ic_type` 358 - Initial condition type, (`sphere`, `cylinder`, `cosine_hill`, `skew`, `wave`, `boundary_layer`) 359 - `sphere` 360 - 361 362* - `-advection_ic_bubble_rc` 363 - For `sphere` or `cylinder` IC, characteristic radius of thermal bubble 364 - `1000` 365 - `m` 366 367* - `-advection_ic_bubble_continuity` 368 - For `sphere` or `cylinder` IC, different shapes of bubble, (`smooth`, `back_sharp`, `thick`, `cosine`) 369 - `smooth` 370 - 371 372* - `-advection_ic_wave_type` 373 - For `wave` IC, the wave form used for `-advection_ic_type wave` (`sine`, `square`) 374 - `sine` 375 - 376 377* - `-advection_ic_wave_frequency` 378 - For `wave` IC, frequency of the wave 379 - $2\pi$ 380 - `1/s` 381 382* - `-advection_ic_wave_phase` 383 - For `wave` IC, phase angle of the wave 384 - $2\pi$ 385 - 386 387* - `-advection_ic_bl_height_factor` 388 - For `boundary_layer` IC, sets the height of the linear boundary layer initial condition in proportion to the domain height 389 - $1$ 390 - 391::: 392 393For 3D advection, an example of the `rotation` mode can be run with: 394 395``` 396./navierstokes -problem advection -dm_plex_box_faces 10,10,10 -dm_plex_dim 3 -dm_plex_box_lower 0,0,0 -dm_plex_box_upper 8000,8000,8000 -bc_wall 1,2,3,4,5,6 -wall_comps 4 -wind_type rotation -implicit -stab su 397``` 398 399and the `translation` mode with: 400 401``` 402./navierstokes -problem advection -dm_plex_box_faces 10,10,10 -dm_plex_dim 3 -dm_plex_box_lower 0,0,0 -dm_plex_box_upper 8000,8000,8000 -wind_type translation -wind_translation .5,-1,0 -bc_inflow 1,2,3,4,5,6 403``` 404 405For 2D advection, an example of the `rotation` mode can be run with: 406 407``` 408./navierstokes -problem advection -dm_plex_box_faces 20,20 -dm_plex_box_lower 0,0 -dm_plex_box_upper 1000,1000 -bc_wall 1,2,3,4 -wall_comps 4 -wind_type rotation -implicit -stab supg 409``` 410 411and the `translation` mode with: 412 413``` 414./navierstokes -problem advection -dm_plex_box_faces 20,20 -dm_plex_box_lower 0,0 -dm_plex_box_upper 1000,1000 -units_meter 1e-4 -wind_type translation -wind_translation 1,-.5 -bc_inflow 1,2,3,4 415``` 416Note the lengths in `-dm_plex_box_upper` are given in meters, and will be nondimensionalized according to `-units_meter`. 417 418## Inviscid Ideal Gas 419 420### Isentropic Euler vortex 421 422For the Isentropic Vortex problem, the following additional command-line options are available: 423 424:::{list-table} Isentropic Vortex Runtime Options 425:header-rows: 1 426 427* - Option 428 - Description 429 - Default value 430 - Unit 431 432* - `-center` 433 - Location of vortex center 434 - `(lx,ly,lz)/2` 435 - `(m,m,m)` 436 437* - `-units_meter` 438 - 1 meter in scaled length units 439 - `1E-2` 440 - 441 442* - `-units_second` 443 - 1 second in scaled time units 444 - `1E-2` 445 - 446 447* - `-mean_velocity` 448 - Background velocity vector 449 - `(1,1,0)` 450 - 451 452* - `-vortex_strength` 453 - Strength of vortex < 10 454 - `5` 455 - 456 457* - `-c_tau` 458 - Stabilization constant 459 - `0.5` 460 - 461::: 462 463This problem can be run with: 464 465``` 466./navierstokes -problem euler_vortex -dm_plex_box_faces 20,20,1 -dm_plex_box_lower 0,0,0 -dm_plex_box_upper 1000,1000,50 -dm_plex_dim 3 -bc_inflow 4,6 -bc_outflow 3,5 -bc_symmetry_z 1,2 -mean_velocity .5,-.8,0. 467``` 468 469### Sod shock tube 470 471For the Shock Tube problem, the following additional command-line options are available: 472 473:::{list-table} Shock Tube Runtime Options 474:header-rows: 1 475 476* - Option 477 - Description 478 - Default value 479 - Unit 480 481* - `-units_meter` 482 - 1 meter in scaled length units 483 - `1E-2` 484 - 485 486* - `-units_second` 487 - 1 second in scaled time units 488 - `1E-2` 489 - 490 491* - `-yzb` 492 - Use YZB discontinuity capturing 493 - `none` 494 - 495 496* - `-stab` 497 - Stabilization method (`none`, `su`, or `supg`) 498 - `none` 499 - 500::: 501 502This problem can be run with: 503 504``` 505./navierstokes -problem shocktube -yzb -stab su -bc_symmetry_z 3,4 -bc_symmetry_y 1,2 -bc_wall 5,6 -dm_plex_dim 3 -dm_plex_box_lower 0,0,0 -dm_plex_box_upper 1000,100,100 -dm_plex_box_faces 200,1,1 -units_second 0.1 506``` 507 508## Newtonian viscosity, Ideal Gas 509 510For the Density Current, Channel, and Blasius problems, the following common command-line options are available: 511 512:::{list-table} Newtonian Ideal Gas problems Runtime Options 513:header-rows: 1 514 515* - Option 516 - Description 517 - Default value 518 - Unit 519 520* - `-units_meter` 521 - 1 meter in scaled length units 522 - `1` 523 - 524 525* - `-units_second` 526 - 1 second in scaled time units 527 - `1` 528 - 529 530* - `-units_kilogram` 531 - 1 kilogram in scaled mass units 532 - `1` 533 - 534 535* - `-units_Kelvin` 536 - 1 Kelvin in scaled temperature units 537 - `1` 538 - 539 540* - `-stab` 541 - Stabilization method (`none`, `su`, or `supg`) 542 - `none` 543 - 544 545* - `-c_tau` 546 - Stabilization constant, $c_\tau$ 547 - `0.5` 548 - 549 550* - `-Ctau_t` 551 - Stabilization time constant, $C_t$ 552 - `1.0` 553 - 554 555* - `-Ctau_v` 556 - Stabilization viscous constant, $C_v$ 557 - `36, 60, 128 for degree = 1, 2, 3` 558 - 559 560* - `-Ctau_C` 561 - Stabilization continuity constant, $C_c$ 562 - `1.0` 563 - 564 565* - `-Ctau_M` 566 - Stabilization momentum constant, $C_m$ 567 - `1.0` 568 - 569 570* - `-Ctau_E` 571 - Stabilization energy constant, $C_E$ 572 - `1.0` 573 - 574 575* - `-div_diff_flux_projection_method` 576 - Method used to calculate divergence of diffusive flux projection (`none`, `direct`, or `indirect`) 577 - `none` 578 - 579 580* - `-div_diff_flux_projection_ksp*` 581 - Control the KSP object for the projection of the divergence of diffusive flux 582 - N/A 583 - 584 585* - `-cv` 586 - Heat capacity at constant volume 587 - `717` 588 - `J/(kg K)` 589 590* - `-cp` 591 - Heat capacity at constant pressure 592 - `1004` 593 - `J/(kg K)` 594 595* - `-gravity` 596 - Gravitational acceleration vector 597 - `0,0,0` 598 - `m/s^2` 599 600* - `-lambda` 601 - Stokes hypothesis second viscosity coefficient 602 - `-2/3` 603 - 604 605* - `-mu` 606 - Shear dynamic viscosity coefficient 607 - `1.8e-5` 608 - `Pa s` 609 610* - `-k` 611 - Thermal conductivity 612 - `0.02638` 613 - `W/(m K)` 614 615* - `-newtonian_unit_tests` 616 - Developer option to test properties 617 - `false` 618 - boolean 619 620* - `-state_var` 621 - State variables to solve solution with. `conservative` ($\rho, \rho \bm{u}, \rho e$), `primitive` ($P, \bm{u}, T$), or `entropy` ($\frac{\gamma - s}{\gamma - 1} - \frac{\rho}{P} (e - c_v T),\ \frac{\rho}{P} \bm{u},\ -\frac{\rho}{P}$) where $s = \ln(P\rho^{-\gamma})$ 622 - `conservative` 623 - string 624 625* - `-idl_decay_time` 626 - Characteristic timescale of the pressure deviance decay. The timestep is good starting point 627 - `-1` (disabled) 628 - `s` 629 630* - `-idl_start` 631 - Start of IDL in the x direction 632 - `0` 633 - `m` 634 635* - `-idl_length` 636 - Length of IDL in the positive x direction 637 - `0` 638 - `m` 639 640* - `-idl_pressure` 641 - Pressure used for IDL reference pressure 642 - `-reference_pressure` 643 - `Pa` 644 645* - `-sgs_model_type` 646 - Type of subgrid stress model to use. Currently only `data_driven` is available 647 - `none` 648 - string 649 650* - `-sgs_model_dd_leakyrelu_alpha` 651 - Slope parameter for Leaky ReLU activation function. `0` corresponds to normal ReLU 652 - 0 653 - 654 655* - `-sgs_model_dd_parameter_dir` 656 - Path to directory with data-driven model parameters (weights, biases, etc.) 657 - `./dd_sgs_parameters` 658 - string 659 660* - `-sgs_model_dd_model_implementation` 661 - Which computational implementation to use for SGS DD model (`fused`, `sequential_ceed`, `sequential_torch`) 662 - `fused` 663 - string 664 665* - `-sgs_model_dd_torch_model_path` 666 - Path to the PyTorch `*.pt` file containing the DD inference model 667 - 668 - string 669 670* - `-sgs_model_dd_torch_model_device` 671 - What hardware to perform the model inference on (`cpu`, `cuda`, `hip`, `xpu`) 672 - Default matches the libCEED backend 673 - string 674 675* - `-diff_filter_monitor` 676 - Enable differential filter TSMonitor 677 - `false` 678 - boolean 679 680* - `-diff_filter_grid_based_width` 681 - Use filter width based on the grid size 682 - `false` 683 - boolean 684 685* - `-diff_filter_width_scaling` 686 - Anisotropic scaling for filter width in wall-aligned coordinates (snz) 687 - `1,1,1` 688 - `m` 689 690* - `-diff_filter_kernel_scaling` 691 - Scaling to make differential kernel size equivalent to other filter kernels 692 - `0.1` 693 - `m^2` 694 695* - `-diff_filter_wall_damping_function` 696 - Damping function to use at the wall for anisotropic filtering (`none`, `van_driest`) 697 - `none` 698 - string 699 700* - `-diff_filter_wall_damping_constant` 701 - Constant for the wall-damping function. $A^+$ for `van_driest` damping function. 702 - 25 703 - 704 705* - `-diff_filter_friction_length` 706 - Friction length associated with the flow, $\delta_\nu$. Used in wall-damping functions 707 - 0 708 - `m` 709 710* - `-sgs_train_enable` 711 - Whether to enable *in situ* training of data-driven SGS model. Require building with SmartRedis. 712 - `false` 713 - boolean 714 715* - `-sgs_train_write_data_interval` 716 - Number of timesteps between writing training data into SmartRedis database 717 - `1` 718 - 719 720* - `-sgs_train_overwrite_data` 721 - Whether new training data should overwrite old data on database 722 - `true` 723 - boolean 724 725* - `-sgs_train_filter_widths` 726 - List of scalar values for different filter widths to calculate for training data 727 - 728 - `m` 729 730* - `-smartsim_collocated_num_ranks` 731 - Number of MPI ranks associated with each collocated database (i.e. ranks per node) 732 - `1` 733 - 734::: 735 736### Gaussian Wave 737 738The Gaussian wave problem has the following command-line options in addition to the Newtonian Ideal Gas options: 739 740:::{list-table} Gaussian Wave Runtime Options 741:header-rows: 1 742 743* - Option 744 - Description 745 - Default value 746 - Unit 747 748* - `-freestream_riemann` 749 - Riemann solver for boundaries (HLL or HLLC) 750 - `hllc` 751 - 752 753* - `-freestream_velocity` 754 - Freestream velocity vector 755 - `0,0,0` 756 - `m/s` 757 758* - `-freestream_temperature` 759 - Freestream temperature 760 - `288` 761 - `K` 762 763* - `-freestream_pressure` 764 - Freestream pressure 765 - `1.01e5` 766 - `Pa` 767 768* - `-epicenter` 769 - Coordinates of center of perturbation 770 - `0,0,0` 771 - `m` 772 773* - `-amplitude` 774 - Amplitude of the perturbation 775 - `0.1` 776 - 777 778* - `-width` 779 - Width parameter of the perturbation 780 - `0.002` 781 - `m` 782 783::: 784 785This problem can be run with the `examples/gaussianwave.yaml` file via: 786 787``` 788./build/navierstokes -options_file examples/gaussianwave.yaml 789``` 790 791```{literalinclude} ../examples/gaussianwave.yaml 792:language: yaml 793``` 794 795### Vortex Shedding - Flow past Cylinder 796 797The vortex shedding, flow past cylinder problem has the following command-line options in addition to the Newtonian Ideal Gas options: 798 799:::{list-table} Vortex Shedding Runtime Options 800:header-rows: 1 801 802* - Option 803 - Description 804 - Default value 805 - Unit 806 807* - `-freestream_velocity` 808 - Freestream velocity vector 809 - `0,0,0` 810 - `m/s` 811 812* - `-freestream_temperature` 813 - Freestream temperature 814 - `288` 815 - `K` 816 817* - `-freestream_pressure` 818 - Freestream pressure 819 - `1.01e5` 820 - `Pa` 821 822::: 823 824The initial condition is taken from `-reference_temperature` and `-reference_pressure`. 825To run this problem, first generate a mesh: 826 827```console 828$ make -C examples/meshes 829``` 830 831Then run by building the executable and running: 832 833```console 834$ make -j 835$ mpiexec -n 6 build/navierstokes -options_file examples/vortexshedding.yaml -{ts,snes}_monitor_ 836``` 837 838The vortex shedding period is roughly 5.6 and this problem runs until time 100 (2000 time steps). 839The above run writes a file named `force.csv` (see `ts_monitor_wall_force` in `examples/vortexshedding.yaml`), which can be postprocessed by running to create a figure showing lift and drag coefficients over time. 840 841```console 842$ python postprocess/vortexshedding.py 843``` 844 845```{literalinclude} ../examples/vortexshedding.yaml 846:language: yaml 847``` 848 849### Density current 850 851The Density Current problem has the following command-line options in addition to the Newtonian Ideal Gas options: 852 853:::{list-table} Density Current Runtime Options 854:header-rows: 1 855 856* - Option 857 - Description 858 - Default value 859 - Unit 860 861* - `-center` 862 - Location of bubble center 863 - `(lx,ly,lz)/2` 864 - `(m,m,m)` 865 866* - `-dc_axis` 867 - Axis of density current cylindrical anomaly, or `(0,0,0)` for spherically symmetric 868 - `(0,0,0)` 869 - 870 871* - `-rc` 872 - Characteristic radius of thermal bubble 873 - `1000` 874 - `m` 875 876* - `-theta0` 877 - Reference potential temperature 878 - `300` 879 - `K` 880 881* - `-thetaC` 882 - Perturbation of potential temperature 883 - `-15` 884 - `K` 885 886* - `-P0` 887 - Atmospheric pressure 888 - `1E5` 889 - `Pa` 890 891* - `-N` 892 - Brunt-Vaisala frequency 893 - `0.01` 894 - `1/s` 895::: 896 897This problem can be run with: 898 899``` 900./navierstokes -problem density_current -dm_plex_box_faces 16,1,8 -degree 1 -dm_plex_box_lower 0,0,0 -dm_plex_box_upper 2000,125,1000 -dm_plex_dim 3 -rc 400. -bc_wall 1,2,5,6 -wall_comps 1,2,3 -bc_symmetry_y 3,4 -mu 75 901``` 902 903### Channel flow 904 905The Channel problem has the following command-line options in addition to the Newtonian Ideal Gas options: 906 907:::{list-table} Channel Runtime Options 908:header-rows: 1 909 910* - Option 911 - Description 912 - Default value 913 - Unit 914 915* - `-umax` 916 - Maximum/centerline velocity of the flow 917 - `10` 918 - `m/s` 919 920* - `-theta0` 921 - Reference potential temperature 922 - `300` 923 - `K` 924 925* - `-P0` 926 - Atmospheric pressure 927 - `1E5` 928 - `Pa` 929 930* - `-body_force_scale` 931 - Multiplier for body force (`-1` for flow reversal) 932 - 1 933 - 934::: 935 936This problem can be run with the `examples/channel.yaml` file via: 937 938``` 939./build/navierstokes -options_file examples/channel.yaml 940``` 941```{literalinclude} ../examples/channel.yaml 942:language: yaml 943``` 944 945(example-blasius)= 946 947### Blasius boundary layer 948 949The Blasius problem has the following command-line options in addition to the Newtonian Ideal Gas options: 950 951:::{list-table} Blasius Runtime Options 952:header-rows: 1 953 954* - Option 955 - Description 956 - Default value 957 - Unit 958 959* - `-velocity_infinity` 960 - Freestream velocity 961 - `40` 962 - `m/s` 963 964* - `-temperature_infinity` 965 - Freestream temperature 966 - `288` 967 - `K` 968 969* - `-pressure_infinity` 970 - Atmospheric pressure, also sets IDL reference pressure 971 - `1.01E5` 972 - `Pa` 973 974* - `-temperature_wall` 975 - Wall temperature 976 - `288` 977 - `K` 978 979* - `-delta0` 980 - Boundary layer height at the inflow 981 - `4.2e-3` 982 - `m` 983 984* - `-platemesh_modify_mesh` 985 - Whether to modify the mesh using the given options below. 986 - `false` 987 - 988 989* - `-platemesh_refine_height` 990 - Height at which `-platemesh_Ndelta` number of elements should refined into 991 - `5.9E-4` 992 - `m` 993 994* - `-platemesh_Ndelta` 995 - Number of elements to keep below `-platemesh_refine_height` 996 - `45` 997 - 998 999* - `-platemesh_growth` 1000 - Growth rate of the elements in the refinement region 1001 - `1.08` 1002 - 1003 1004* - `-platemesh_top_angle` 1005 - Downward angle of the top face of the domain. This face serves as an outlet. 1006 - `5` 1007 - `degrees` 1008 1009* - `-platemesh_y_node_locs_path` 1010 - Path to file with y node locations. If empty, will use mesh warping instead. 1011 - `""` 1012 - 1013 1014* - `-stg_use` 1015 - Whether to use STG for the inflow conditions 1016 - `false` 1017 - 1018 1019* - `-n_chebyshev` 1020 - Number of Chebyshev terms 1021 - `20` 1022 - 1023 1024* - `-chebyshev_` 1025 - Prefix for Chebyshev snes solve 1026 - 1027 - 1028 1029::: 1030 1031This problem can be run with the `examples/blasius.yaml` file via: 1032 1033``` 1034./build/navierstokes -options_file examples/blasius.yaml 1035``` 1036 1037```{literalinclude} ../examples/blasius.yaml 1038:language: yaml 1039``` 1040 1041### STG Inflow for Flat Plate 1042 1043Using the STG Inflow for the blasius problem adds the following command-line options: 1044 1045:::{list-table} Blasius Runtime Options 1046:header-rows: 1 1047 1048* - Option 1049 - Description 1050 - Default value 1051 - Unit 1052 1053* - `-stg_inflow_path` 1054 - Path to the STGInflow file 1055 - `./STGInflow.dat` 1056 - 1057 1058* - `-stg_rand_path` 1059 - Path to the STGRand file 1060 - `./STGRand.dat` 1061 - 1062 1063* - `-stg_alpha` 1064 - Growth rate of the wavemodes 1065 - `1.01` 1066 - 1067 1068* - `-stg_u0` 1069 - Convective velocity, $U_0$ 1070 - `0.0` 1071 - `m/s` 1072 1073* - `-stg_mean_only` 1074 - Only impose the mean velocity (no fluctutations) 1075 - `false` 1076 - 1077 1078* - `-stg_strong` 1079 - Strongly enforce the STG inflow boundary condition 1080 - `false` 1081 - 1082 1083* - `-stg_fluctuating_IC` 1084 - "Extrude" the fluctuations through the domain as an initial condition 1085 - `false` 1086 - 1087 1088* - `-stg_dx` 1089 - Set the element size in the x direction. Default is calculated for box meshes, assuming equispaced elements. 1090 - 1091 - `m` 1092 1093* - `-stg_h_scale_factor` 1094 - Scale element size for cutoff frequency calculation 1095 - $1/p$ 1096 - 1097 1098::: 1099 1100This problem can be run with the `examples/blasius.yaml` file via: 1101 1102``` 1103./build/navierstokes -options_file examples/blasius.yaml -stg_use true 1104``` 1105 1106Note the added `-stg_use true` flag 1107This overrides the `stg: use: false` setting in the `examples/blasius.yaml` file, enabling the use of the STG inflow. 1108