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 solution binary file from which to continue from 72 - `[output_dir]/ns-solution.bin` 73 74* - `-continue_time_filename` 75 - Path to time stamp binary file (only for legacy checkpoints) 76 - `[output_dir]/ns-time.bin` 77 78* - `-bc_wall` 79 - Use wall boundary conditions on this list of faces 80 - 81 82* - `-wall_comps` 83 - An array of constrained component numbers for wall BCs 84 - 85 86* - `-bc_slip` 87 - Use weak slip boundary condition on this list of faces 88 - 89 90* - `-bc_symmetry_x` 91 - Use symmetry boundary conditions, for the x component, on this list of faces 92 - 93 94* - `-bc_symmetry_y` 95 - Use symmetry boundary conditions, for the y component, on this list of faces 96 - 97 98* - `-bc_symmetry_z` 99 - Use symmetry boundary conditions, for the z component, on this list of faces 100 - 101 102* - `-bc_inflow` 103 - Use inflow boundary conditions on this list of faces 104 - 105 106* - `-bc_outflow` 107 - Use outflow boundary conditions on this list of faces 108 - 109 110* - `-bc_freestream` 111 - Use freestream boundary conditions on this list of faces 112 - 113 114* - `-ts_monitor_turbulence_spanstats_collect_interval` 115 - Number of timesteps between statistics collection 116 - `1` 117 118* - `-ts_monitor_turbulence_spanstats_viewer` 119 - Sets the PetscViewer for the statistics file writing, such as `cgns:output-%d.cgns` (requires PETSc `--download-cgns`). Also turns the statistics collection on. 120 - 121 122* - `-ts_monitor_turbulence_spanstats_viewer_interval` 123 - Number of timesteps between statistics file writing (`-1` means only at end of run) 124 - `-1` 125 126* - `-ts_monitor_turbulence_spanstats_viewer_cgns_batch_size` 127 - Number of frames written per CGNS file if the CGNS file name includes a format specifier (`%d`). 128 - `20` 129 130* - `-ts_monitor_wall_force` 131 - Viewer for the force on each no-slip wall, e.g., `ascii:force.csv:ascii_csv` to write a CSV file. 132 - 133 134* - `-mesh_transform` 135 - Transform the mesh, usually for an initial box mesh. 136 - `none` 137 138* - `-snes_view` 139 - View PETSc `SNES` nonlinear solver configuration 140 - 141 142* - `-log_view` 143 - View PETSc performance log 144 - 145 146* - `-help` 147 - View comprehensive information about run-time options 148 - 149 150* - `-test_type` 151 - Run in test mode and specify whether solution (`solver`) or turbulent statistics (`turb_spanstats`) output should be verified 152 - `none` 153 154* - `-compare_final_state_atol` 155 - Test absolute tolerance 156 - `1E-11` 157 158* - `-compare_final_state_filename` 159 - Test filename 160 - 161 162::: 163 164For 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: 165 166:::{list-table} 2D Face ID Labels 167:header-rows: 1 168* - PETSc Face Name 169 - Cartesian direction 170 - Face ID 171 172* - faceMarkerBottom 173 - -z 174 - 1 175 176* - faceMarkerRight 177 - +x 178 - 2 179 180* - faceMarkerTop 181 - +z 182 - 3 183 184* - faceMarkerLeft 185 - -x 186 - 4 187::: 188 189:::{list-table} 3D Face ID Labels 190:header-rows: 1 191* - PETSc Face Name 192 - Cartesian direction 193 - Face ID 194 195* - faceMarkerBottom 196 - -z 197 - 1 198 199* - faceMarkerTop 200 - +z 201 - 2 202 203* - faceMarkerFront 204 - -y 205 - 3 206 207* - faceMarkerBack 208 - +y 209 - 4 210 211* - faceMarkerRight 212 - +x 213 - 5 214 215* - faceMarkerLeft 216 - -x 217 - 6 218::: 219 220## Boundary conditions 221 222Boundary conditions for compressible viscous flows are notoriously tricky. 223Here we offer some recommendations. 224 225### Inflow 226 227If 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). 228It is stable and the least reflective boundary condition for acoustics. 229 230If near a viscous wall, you may want a specified inflow profile. 231Use `bc_inflow` and see {ref}`example-blasius` and discussion of synthetic turbulence generation for ways to analytically generate developed inflow profiles. 232These 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. 233The strong approach gives sharper resolution of velocity structures. 234We have described the primitive variable formulation here; the conservative variants are similar, but not equivalent. 235 236### Outflow 237 238If you know the complete exterior state, `bc_freestream` is the least reflective boundary condition, but is disruptive to viscous flow structures. 239If thermal anomalies must exit the domain, the Riemann solver must resolve the contact wave to avoid reflections. 240The default Riemann solver, HLLC, is sufficient in this regard while the simpler HLL converts thermal structures exiting the domain into grid-scale reflecting acoustics. 241 242If 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. 243 244The 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). 245In our experience, `riemann` is slightly less reflective but produces similar flows in cases of strict outflow. 246The `pressure` variant is retained to facilitate comparison with other codes, such as PHASTA-C, but we recommend `riemann` for general use. 247 248### Periodicity 249 250PETSc provides two ways to specify periodicity: 251 2521. Topological periodicity, in which the donor and receiver dofs are the same, obtained using: 253 254```yaml 255dm_plex: 256 shape: box 257 box_faces: 10,12,4 258 box_bd: none,none,periodic 259``` 260 261The coordinates for such cases are stored as a new field with special cell-based indexing to enable wrapping through the boundary. 262This choice of coordinates prevents evaluating boundary integrals that cross the periodicity, such as for the outflow Riemann problem in the presence of spanwise periodicity. 263 2642. Isoperiodicity, in which the donor and receiver dofs are distinct in local vectors. This is obtained using `zbox`, as in: 265 266```yaml 267dm_plex: 268 shape: zbox 269 box_faces: 10,12,4 270 box_bd: none,none,periodic 271``` 272 273Isoperiodicity enables standard boundary integrals, and is recommended for general use. 274At the time of this writing, it only supports one direction of periodicity. 275The `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. 276 277## Advection-Diffusion 278 279There is a reduced mode for pure advection, which holds density $\rho$ and momentum density $\rho \bm u$ constant while advecting "total energy density" $E$. 280The advection problems can be run in both 2D and 3D, based on the DM defined for the problem. 281The following additional command-line options are available: 282 283:::{list-table} Advection Runtime Options 284:header-rows: 1 285 286* - Option 287 - Description 288 - Default value 289 - Unit 290 291* - `-rc` 292 - Characteristic radius of thermal bubble 293 - `1000` 294 - `m` 295 296* - `-units_meter` 297 - 1 meter in scaled length units 298 - `1E-2` 299 - 300 301* - `-units_second` 302 - 1 second in scaled time units 303 - `1E-2` 304 - 305 306* - `-units_kilogram` 307 - 1 kilogram in scaled mass units 308 - `1E-6` 309 - 310 311* - `-strong_form` 312 - Strong (1) or weak/integrated by parts (0) residual 313 - `0` 314 - 315 316* - `-stab` 317 - Stabilization method (`none`, `su`, or `supg`) 318 - `none` 319 - 320 321* - `-stab_tau` 322 - Formulation for $\tau$ in stabilization (`ctau`, `advdiff_shakib`) 323 - `ctau` 324 - 325 326* - `-Ctau_t` 327 - Scaling factor on the temporal portion of the $\tau$ formulation 328 - 0. 329 - 330 331* - `-Ctau_a` 332 - Scaling factor on the advection portion of the $\tau$ formulation 333 - $P^2$ 334 - 335 336* - `-CtauS` 337 - Scale coefficient for stabilization tau (nondimensional) 338 - `0` 339 - 340 341* - `-wind_type` 342 - Wind type in Advection (`rotation` or `translation`) 343 - `rotation` 344 - 345 346* - `-wind_translation` 347 - Constant wind vector when `-wind_type translation` 348 - `1,0,0` 349 - 350 351* - `-diffusion_coeff` 352 - Diffusion coefficient 353 - `0` 354 - 355 356* - `-E_wind` 357 - Total energy of inflow wind when `-wind_type translation` 358 - `1E6` 359 - `J` 360 361* - `-advection_ic_type` 362 - Initial condition type, (`sphere`, `cylinder`, `cosine_hill`, `skew`, `wave`) 363 - `sphere` 364 - 365 366* - `-bubble_continuity` 367 - Different shapes for `sphere` and `cylinder` initial conditions, from `smooth`, `back_sharp`, `thick`, or `cosine` 368 - `smooth` 369 - 370 371* - `-wave_type` 372 - The wave form used for `-advection_ic_type wave` (`sine`, `square`) 373 - `sine` 374 - 375 376* - `-wave_frequency` 377 - Frequency of the wave 378 - $2\pi$ 379 - `1/s` 380 381* - `-wave_phase` 382 - Phase angle of the wave 383 - $2\pi$ 384 - 385::: 386 387For 3D advection, an example of the `rotation` mode can be run with: 388 389``` 390./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 391``` 392 393and the `translation` mode 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 -wind_type translation -wind_translation .5,-1,0 -bc_inflow 1,2,3,4,5,6 397``` 398 399For 2D advection, an example of the `rotation` mode can be run with: 400 401``` 402./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 403``` 404 405and the `translation` mode 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 -units_meter 1e-4 -wind_type translation -wind_translation 1,-.5 -bc_inflow 1,2,3,4 409``` 410Note the lengths in `-dm_plex_box_upper` are given in meters, and will be nondimensionalized according to `-units_meter`. 411 412## Inviscid Ideal Gas 413 414### Isentropic Euler vortex 415 416For the Isentropic Vortex problem, the following additional command-line options are available: 417 418:::{list-table} Isentropic Vortex Runtime Options 419:header-rows: 1 420 421* - Option 422 - Description 423 - Default value 424 - Unit 425 426* - `-center` 427 - Location of vortex center 428 - `(lx,ly,lz)/2` 429 - `(m,m,m)` 430 431* - `-units_meter` 432 - 1 meter in scaled length units 433 - `1E-2` 434 - 435 436* - `-units_second` 437 - 1 second in scaled time units 438 - `1E-2` 439 - 440 441* - `-mean_velocity` 442 - Background velocity vector 443 - `(1,1,0)` 444 - 445 446* - `-vortex_strength` 447 - Strength of vortex < 10 448 - `5` 449 - 450 451* - `-c_tau` 452 - Stabilization constant 453 - `0.5` 454 - 455::: 456 457This problem can be run with: 458 459``` 460./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. 461``` 462 463### Sod shock tube 464 465For the Shock Tube problem, the following additional command-line options are available: 466 467:::{list-table} Shock Tube Runtime Options 468:header-rows: 1 469 470* - Option 471 - Description 472 - Default value 473 - Unit 474 475* - `-units_meter` 476 - 1 meter in scaled length units 477 - `1E-2` 478 - 479 480* - `-units_second` 481 - 1 second in scaled time units 482 - `1E-2` 483 - 484 485* - `-yzb` 486 - Use YZB discontinuity capturing 487 - `none` 488 - 489 490* - `-stab` 491 - Stabilization method (`none`, `su`, or `supg`) 492 - `none` 493 - 494::: 495 496This problem can be run with: 497 498``` 499./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 0.1 500``` 501 502## Newtonian viscosity, Ideal Gas 503 504For the Density Current, Channel, and Blasius problems, the following common command-line options are available: 505 506:::{list-table} Newtonian Ideal Gas problems Runtime Options 507:header-rows: 1 508 509* - Option 510 - Description 511 - Default value 512 - Unit 513 514* - `-units_meter` 515 - 1 meter in scaled length units 516 - `1` 517 - 518 519* - `-units_second` 520 - 1 second in scaled time units 521 - `1` 522 - 523 524* - `-units_kilogram` 525 - 1 kilogram in scaled mass units 526 - `1` 527 - 528 529* - `-units_Kelvin` 530 - 1 Kelvin in scaled temperature units 531 - `1` 532 - 533 534* - `-stab` 535 - Stabilization method (`none`, `su`, or `supg`) 536 - `none` 537 - 538 539* - `-c_tau` 540 - Stabilization constant, $c_\tau$ 541 - `0.5` 542 - 543 544* - `-Ctau_t` 545 - Stabilization time constant, $C_t$ 546 - `1.0` 547 - 548 549* - `-Ctau_v` 550 - Stabilization viscous constant, $C_v$ 551 - `36, 60, 128 for degree = 1, 2, 3` 552 - 553 554* - `-Ctau_C` 555 - Stabilization continuity constant, $C_c$ 556 - `1.0` 557 - 558 559* - `-Ctau_M` 560 - Stabilization momentum constant, $C_m$ 561 - `1.0` 562 - 563 564* - `-Ctau_E` 565 - Stabilization energy constant, $C_E$ 566 - `1.0` 567 - 568 569* - `-div_diff_flux_projection_method` 570 - Method used to calculate divergence of diffusive flux projection (`none`, `direct`, or `indirect`) 571 - `none` 572 - 573 574* - `-div_diff_flux_projection_ksp*` 575 - Control the KSP object for the projection of the divergence of diffusive flux 576 - N/A 577 - 578 579* - `-cv` 580 - Heat capacity at constant volume 581 - `717` 582 - `J/(kg K)` 583 584* - `-cp` 585 - Heat capacity at constant pressure 586 - `1004` 587 - `J/(kg K)` 588 589* - `-gravity` 590 - Gravitational acceleration vector 591 - `0,0,0` 592 - `m/s^2` 593 594* - `-lambda` 595 - Stokes hypothesis second viscosity coefficient 596 - `-2/3` 597 - 598 599* - `-mu` 600 - Shear dynamic viscosity coefficient 601 - `1.8e-5` 602 - `Pa s` 603 604* - `-k` 605 - Thermal conductivity 606 - `0.02638` 607 - `W/(m K)` 608 609* - `-newtonian_unit_tests` 610 - Developer option to test properties 611 - `false` 612 - boolean 613 614* - `-state_var` 615 - 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 $s = \ln(P\rho^{-\gamma})$ 616 - `conservative` 617 - string 618 619* - `-idl_decay_time` 620 - Characteristic timescale of the pressure deviance decay. The timestep is good starting point 621 - `-1` (disabled) 622 - `s` 623 624* - `-idl_start` 625 - Start of IDL in the x direction 626 - `0` 627 - `m` 628 629* - `-idl_length` 630 - Length of IDL in the positive x direction 631 - `0` 632 - `m` 633 634* - `-idl_pressure` 635 - Pressure used for IDL reference pressure 636 - `-reference_pressure` 637 - `Pa` 638 639* - `-sgs_model_type` 640 - Type of subgrid stress model to use. Currently only `data_driven` is available 641 - `none` 642 - string 643 644* - `-sgs_model_dd_leakyrelu_alpha` 645 - Slope parameter for Leaky ReLU activation function. `0` corresponds to normal ReLU 646 - 0 647 - 648 649* - `-sgs_model_dd_parameter_dir` 650 - Path to directory with data-driven model parameters (weights, biases, etc.) 651 - `./dd_sgs_parameters` 652 - string 653 654* - `-sgs_model_dd_model_implementation` 655 - Which computational implementation to use for SGS DD model (`fused`, `sequential_ceed`, `sequential_torch`) 656 - `fused` 657 - string 658 659* - `-sgs_model_dd_torch_model_path` 660 - Path to the PyTorch `*.pt` file containing the DD inference model 661 - 662 - string 663 664* - `-sgs_model_dd_torch_model_device` 665 - What hardware to perform the model inference on (`cpu`, `cuda`, `hip`, `xpu`) 666 - Default matches the libCEED backend 667 - string 668 669* - `-diff_filter_monitor` 670 - Enable differential filter TSMonitor 671 - `false` 672 - boolean 673 674* - `-diff_filter_grid_based_width` 675 - Use filter width based on the grid size 676 - `false` 677 - boolean 678 679* - `-diff_filter_width_scaling` 680 - Anisotropic scaling for filter width in wall-aligned coordinates (snz) 681 - `1,1,1` 682 - `m` 683 684* - `-diff_filter_kernel_scaling` 685 - Scaling to make differential kernel size equivalent to other filter kernels 686 - `0.1` 687 - `m^2` 688 689* - `-diff_filter_wall_damping_function` 690 - Damping function to use at the wall for anisotropic filtering (`none`, `van_driest`) 691 - `none` 692 - string 693 694* - `-diff_filter_wall_damping_constant` 695 - Constant for the wall-damping function. $A^+$ for `van_driest` damping function. 696 - 25 697 - 698 699* - `-diff_filter_friction_length` 700 - Friction length associated with the flow, $\delta_\nu$. Used in wall-damping functions 701 - 0 702 - `m` 703 704* - `-sgs_train_enable` 705 - Whether to enable *in situ* training of data-driven SGS model. Require building with SmartRedis. 706 - `false` 707 - boolean 708 709* - `-sgs_train_write_data_interval` 710 - Number of timesteps between writing training data into SmartRedis database 711 - `1` 712 - 713 714* - `-sgs_train_overwrite_data` 715 - Whether new training data should overwrite old data on database 716 - `true` 717 - boolean 718 719* - `-sgs_train_filter_widths` 720 - List of scalar values for different filter widths to calculate for training data 721 - 722 - `m` 723 724* - `-smartsim_collocated_num_ranks` 725 - Number of MPI ranks associated with each collocated database (i.e. ranks per node) 726 - `1` 727 - 728::: 729 730### Gaussian Wave 731 732The Gaussian wave problem has the following command-line options in addition to the Newtonian Ideal Gas options: 733 734:::{list-table} Gaussian Wave Runtime Options 735:header-rows: 1 736 737* - Option 738 - Description 739 - Default value 740 - Unit 741 742* - `-freestream_riemann` 743 - Riemann solver for boundaries (HLL or HLLC) 744 - `hllc` 745 - 746 747* - `-freestream_velocity` 748 - Freestream velocity vector 749 - `0,0,0` 750 - `m/s` 751 752* - `-freestream_temperature` 753 - Freestream temperature 754 - `288` 755 - `K` 756 757* - `-freestream_pressure` 758 - Freestream pressure 759 - `1.01e5` 760 - `Pa` 761 762* - `-epicenter` 763 - Coordinates of center of perturbation 764 - `0,0,0` 765 - `m` 766 767* - `-amplitude` 768 - Amplitude of the perturbation 769 - `0.1` 770 - 771 772* - `-width` 773 - Width parameter of the perturbation 774 - `0.002` 775 - `m` 776 777::: 778 779This problem can be run with the `examples/gaussianwave.yaml` file via: 780 781``` 782./build/navierstokes -options_file examples/gaussianwave.yaml 783``` 784 785```{literalinclude} ../examples/gaussianwave.yaml 786:language: yaml 787``` 788 789### Vortex Shedding - Flow past Cylinder 790 791The vortex shedding, flow past cylinder problem has the following command-line options in addition to the Newtonian Ideal Gas options: 792 793:::{list-table} Vortex Shedding Runtime Options 794:header-rows: 1 795 796* - Option 797 - Description 798 - Default value 799 - Unit 800 801* - `-freestream_velocity` 802 - Freestream velocity vector 803 - `0,0,0` 804 - `m/s` 805 806* - `-freestream_temperature` 807 - Freestream temperature 808 - `288` 809 - `K` 810 811* - `-freestream_pressure` 812 - Freestream pressure 813 - `1.01e5` 814 - `Pa` 815 816::: 817 818The initial condition is taken from `-reference_temperature` and `-reference_pressure`. 819To run this problem, first generate a mesh: 820 821```console 822$ make -C examples/meshes 823``` 824 825Then run by building the executable and running: 826 827```console 828$ make -j 829$ mpiexec -n 6 build/navierstokes -options_file examples/vortexshedding.yaml -{ts,snes}_monitor_ 830``` 831 832The vortex shedding period is roughly 5.6 and this problem runs until time 100 (2000 time steps). 833The 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. 834 835```console 836$ python postprocess/vortexshedding.py 837``` 838 839```{literalinclude} ../examples/vortexshedding.yaml 840:language: yaml 841``` 842 843### Density current 844 845The Density Current problem has the following command-line options in addition to the Newtonian Ideal Gas options: 846 847:::{list-table} Density Current Runtime Options 848:header-rows: 1 849 850* - Option 851 - Description 852 - Default value 853 - Unit 854 855* - `-center` 856 - Location of bubble center 857 - `(lx,ly,lz)/2` 858 - `(m,m,m)` 859 860* - `-dc_axis` 861 - Axis of density current cylindrical anomaly, or `(0,0,0)` for spherically symmetric 862 - `(0,0,0)` 863 - 864 865* - `-rc` 866 - Characteristic radius of thermal bubble 867 - `1000` 868 - `m` 869 870* - `-theta0` 871 - Reference potential temperature 872 - `300` 873 - `K` 874 875* - `-thetaC` 876 - Perturbation of potential temperature 877 - `-15` 878 - `K` 879 880* - `-P0` 881 - Atmospheric pressure 882 - `1E5` 883 - `Pa` 884 885* - `-N` 886 - Brunt-Vaisala frequency 887 - `0.01` 888 - `1/s` 889::: 890 891This problem can be run with: 892 893``` 894./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 75 895``` 896 897### Channel flow 898 899The Channel problem has the following command-line options in addition to the Newtonian Ideal Gas options: 900 901:::{list-table} Channel Runtime Options 902:header-rows: 1 903 904* - Option 905 - Description 906 - Default value 907 - Unit 908 909* - `-umax` 910 - Maximum/centerline velocity of the flow 911 - `10` 912 - `m/s` 913 914* - `-theta0` 915 - Reference potential temperature 916 - `300` 917 - `K` 918 919* - `-P0` 920 - Atmospheric pressure 921 - `1E5` 922 - `Pa` 923 924* - `-body_force_scale` 925 - Multiplier for body force (`-1` for flow reversal) 926 - 1 927 - 928::: 929 930This problem can be run with the `examples/channel.yaml` file via: 931 932``` 933./build/navierstokes -options_file examples/channel.yaml 934``` 935```{literalinclude} ../examples/channel.yaml 936:language: yaml 937``` 938 939(example-blasius)= 940 941### Blasius boundary layer 942 943The Blasius problem has the following command-line options in addition to the Newtonian Ideal Gas options: 944 945:::{list-table} Blasius Runtime Options 946:header-rows: 1 947 948* - Option 949 - Description 950 - Default value 951 - Unit 952 953* - `-velocity_infinity` 954 - Freestream velocity 955 - `40` 956 - `m/s` 957 958* - `-temperature_infinity` 959 - Freestream temperature 960 - `288` 961 - `K` 962 963* - `-pressure_infinity` 964 - Atmospheric pressure, also sets IDL reference pressure 965 - `1.01E5` 966 - `Pa` 967 968* - `-temperature_wall` 969 - Wall temperature 970 - `288` 971 - `K` 972 973* - `-delta0` 974 - Boundary layer height at the inflow 975 - `4.2e-3` 976 - `m` 977 978* - `-platemesh_modify_mesh` 979 - Whether to modify the mesh using the given options below. 980 - `false` 981 - 982 983* - `-platemesh_refine_height` 984 - Height at which `-platemesh_Ndelta` number of elements should refined into 985 - `5.9E-4` 986 - `m` 987 988* - `-platemesh_Ndelta` 989 - Number of elements to keep below `-platemesh_refine_height` 990 - `45` 991 - 992 993* - `-platemesh_growth` 994 - Growth rate of the elements in the refinement region 995 - `1.08` 996 - 997 998* - `-platemesh_top_angle` 999 - Downward angle of the top face of the domain. This face serves as an outlet. 1000 - `5` 1001 - `degrees` 1002 1003* - `-platemesh_y_node_locs_path` 1004 - Path to file with y node locations. If empty, will use mesh warping instead. 1005 - `""` 1006 - 1007 1008* - `-stg_use` 1009 - Whether to use STG for the inflow conditions 1010 - `false` 1011 - 1012 1013* - `-n_chebyshev` 1014 - Number of Chebyshev terms 1015 - `20` 1016 - 1017 1018* - `-chebyshev_` 1019 - Prefix for Chebyshev snes solve 1020 - 1021 - 1022 1023::: 1024 1025This problem can be run with the `examples/blasius.yaml` file via: 1026 1027``` 1028./build/navierstokes -options_file examples/blasius.yaml 1029``` 1030 1031```{literalinclude} ../examples/blasius.yaml 1032:language: yaml 1033``` 1034 1035### STG Inflow for Flat Plate 1036 1037Using the STG Inflow for the blasius problem adds the following command-line options: 1038 1039:::{list-table} Blasius Runtime Options 1040:header-rows: 1 1041 1042* - Option 1043 - Description 1044 - Default value 1045 - Unit 1046 1047* - `-stg_inflow_path` 1048 - Path to the STGInflow file 1049 - `./STGInflow.dat` 1050 - 1051 1052* - `-stg_rand_path` 1053 - Path to the STGRand file 1054 - `./STGRand.dat` 1055 - 1056 1057* - `-stg_alpha` 1058 - Growth rate of the wavemodes 1059 - `1.01` 1060 - 1061 1062* - `-stg_u0` 1063 - Convective velocity, $U_0$ 1064 - `0.0` 1065 - `m/s` 1066 1067* - `-stg_mean_only` 1068 - Only impose the mean velocity (no fluctutations) 1069 - `false` 1070 - 1071 1072* - `-stg_strong` 1073 - Strongly enforce the STG inflow boundary condition 1074 - `false` 1075 - 1076 1077* - `-stg_fluctuating_IC` 1078 - "Extrude" the fluctuations through the domain as an initial condition 1079 - `false` 1080 - 1081 1082* - `-stg_dx` 1083 - Set the element size in the x direction. Default is calculated for box meshes, assuming equispaced elements. 1084 - 1085 - `m` 1086 1087* - `-stg_h_scale_factor` 1088 - Scale element size for cutoff frequency calculation 1089 - $1/p$ 1090 - 1091 1092::: 1093 1094This problem can be run with the `examples/blasius.yaml` file via: 1095 1096``` 1097./build/navierstokes -options_file examples/blasius.yaml -stg_use true 1098``` 1099 1100Note the added `-stg_use true` flag 1101This overrides the `stg: use: false` setting in the `examples/blasius.yaml` file, enabling the use of the STG inflow. 1102