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_filename` 67 - Path to file from which to continue from 68 - 69 70* - `-bc_wall` 71 - Use wall boundary conditions on this list of faces 72 - 73 74* - `-wall_comps` 75 - An array of constrained component numbers for wall BCs 76 - 77 78* - `-bc_slip` 79 - Use weak slip boundary condition on this list of faces 80 - 81 82* - `-bc_symmetry_x` 83 - Use symmetry boundary conditions, for the x component, on this list of faces 84 - 85 86* - `-bc_symmetry_y` 87 - Use symmetry boundary conditions, for the y component, on this list of faces 88 - 89 90* - `-bc_symmetry_z` 91 - Use symmetry boundary conditions, for the z component, on this list of faces 92 - 93 94* - `-bc_inflow` 95 - Use inflow boundary conditions on this list of faces 96 - 97 98* - `-bc_outflow` 99 - Use outflow boundary conditions on this list of faces 100 - 101 102* - `-bc_freestream` 103 - Use freestream boundary conditions on this list of faces 104 - 105 106* - `-ts_monitor_turbulence_spanstats_collect_interval` 107 - Number of timesteps between statistics collection 108 - `1` 109 110* - `-ts_monitor_turbulence_spanstats_viewer` 111 - Sets the PetscViewer for the statistics file writing, such as `cgns:output-%d.cgns` (requires PETSc `--download-cgns`). Also turns the statistics collection on. 112 - 113 114* - `-ts_monitor_turbulence_spanstats_viewer_interval` 115 - Number of timesteps between statistics file writing (`-1` means only at end of run) 116 - `-1` 117 118* - `-ts_monitor_turbulence_spanstats_viewer_cgns_batch_size` 119 - Number of frames written per CGNS file if the CGNS file name includes a format specifier (`%d`). 120 - `20` 121 122* - `-ts_monitor_wall_force` 123 - Viewer for the force on each no-slip wall, e.g., `ascii:force.csv:ascii_csv` to write a CSV file. 124 - 125 126* - `-ts_monitor_total_kinetic_energy` 127 - Viewer for the total kinetic energy in the domain and other terms, e.g., `ascii:total_ke.csv:ascii_csv` to write a CSV file. 128 - 129 130* - `-ts_monitor_total_kinetic_energy_interval` 131 - Number of timesteps between calculating and printing the total kinetic energy 132 - `1` 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* - `-units_meter` 292 - 1 meter in scaled length units 293 - `1E-2` 294 - 295 296* - `-units_second` 297 - 1 second in scaled time units 298 - `1E-2` 299 - 300 301* - `-units_kilogram` 302 - 1 kilogram in scaled mass units 303 - `1E-6` 304 - 305 306* - `-strong_form` 307 - Strong (1) or weak/integrated by parts (0) residual 308 - `0` 309 - 310 311* - `-stab` 312 - Stabilization method (`none`, `su`, or `supg`) 313 - `none` 314 - 315 316* - `-stab_tau` 317 - Formulation for $\tau$ in stabilization (`ctau`, `advdiff_shakib`) 318 - `ctau` 319 - 320 321* - `-Ctau_t` 322 - Scaling factor on the temporal portion of the $\tau$ formulation 323 - 0. 324 - 325 326* - `-Ctau_a` 327 - Scaling factor on the advection portion of the $\tau$ formulation 328 - $P^2$ 329 - 330 331* - `-Ctau_d` 332 - Scaling factor on the diffusion portion of the $\tau$ formulation 333 - $P^4$ 334 - 335 336* - `-CtauS` 337 - Scale coefficient for stabilization tau (nondimensional) 338 - `0` 339 - 340 341* - `-wind_type` 342 - Wind type in Advection (`rotation`, `translation`, `boundary_layer`) 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`, `boundary_layer`) 363 - `sphere` 364 - 365 366* - `-advection_ic_bubble_rc` 367 - For `sphere` or `cylinder` IC, characteristic radius of thermal bubble 368 - `1000` 369 - `m` 370 371* - `-advection_ic_bubble_continuity` 372 - For `sphere` or `cylinder` IC, different shapes of bubble, (`smooth`, `back_sharp`, `thick`, `cosine`) 373 - `smooth` 374 - 375 376* - `-advection_ic_wave_type` 377 - For `wave` IC, the wave form used for `-advection_ic_type wave` (`sine`, `square`) 378 - `sine` 379 - 380 381* - `-advection_ic_wave_frequency` 382 - For `wave` IC, frequency of the wave 383 - $2\pi$ 384 - `1/s` 385 386* - `-advection_ic_wave_phase` 387 - For `wave` IC, phase angle of the wave 388 - $2\pi$ 389 - 390 391* - `-advection_ic_bl_height_factor` 392 - For `boundary_layer` IC, sets the height of the linear boundary layer initial condition in proportion to the domain height 393 - $1$ 394 - 395::: 396 397For 3D advection, an example of the `rotation` mode can be run with: 398 399``` 400./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 401``` 402 403and the `translation` mode with: 404 405``` 406./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 1,2,3,4,5,6 407``` 408 409For 2D advection, an example of the `rotation` mode can be run with: 410 411``` 412./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 413``` 414 415and the `translation` mode with: 416 417``` 418./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 1,2,3,4 419``` 420Note the lengths in `-dm_plex_box_upper` are given in meters, and will be nondimensionalized according to `-units_meter`. 421 422## Inviscid Ideal Gas 423 424### Isentropic Euler vortex 425 426For the Isentropic Vortex problem, the following additional command-line options are available: 427 428:::{list-table} Isentropic Vortex Runtime Options 429:header-rows: 1 430 431* - Option 432 - Description 433 - Default value 434 - Unit 435 436* - `-center` 437 - Location of vortex center 438 - `(lx,ly,lz)/2` 439 - `(m,m,m)` 440 441* - `-units_meter` 442 - 1 meter in scaled length units 443 - `1E-2` 444 - 445 446* - `-units_second` 447 - 1 second in scaled time units 448 - `1E-2` 449 - 450 451* - `-mean_velocity` 452 - Background velocity vector 453 - `(1,1,0)` 454 - 455 456* - `-vortex_strength` 457 - Strength of vortex < 10 458 - `5` 459 - 460 461* - `-c_tau` 462 - Stabilization constant 463 - `0.5` 464 - 465::: 466 467This problem can be run with: 468 469``` 470./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. 471``` 472 473### Sod shock tube 474 475For the Shock Tube problem, the following additional command-line options are available: 476 477:::{list-table} Shock Tube Runtime Options 478:header-rows: 1 479 480* - Option 481 - Description 482 - Default value 483 - Unit 484 485* - `-units_meter` 486 - 1 meter in scaled length units 487 - `1E-2` 488 - 489 490* - `-units_second` 491 - 1 second in scaled time units 492 - `1E-2` 493 - 494 495* - `-yzb` 496 - Use YZB discontinuity capturing 497 - `none` 498 - 499 500* - `-stab` 501 - Stabilization method (`none`, `su`, or `supg`) 502 - `none` 503 - 504::: 505 506This problem can be run with: 507 508``` 509./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 0.1 510``` 511 512## Newtonian viscosity, Ideal Gas 513 514For the Density Current, Channel, and Blasius problems, the following common command-line options are available: 515 516:::{list-table} Newtonian Ideal Gas problems Runtime Options 517:header-rows: 1 518 519* - Option 520 - Description 521 - Default value 522 - Unit 523 524* - `-units_meter` 525 - 1 meter in scaled length units 526 - `1` 527 - 528 529* - `-units_second` 530 - 1 second in scaled time units 531 - `1` 532 - 533 534* - `-units_kilogram` 535 - 1 kilogram in scaled mass units 536 - `1` 537 - 538 539* - `-units_Kelvin` 540 - 1 Kelvin in scaled temperature units 541 - `1` 542 - 543 544* - `-stab` 545 - Stabilization method (`none`, `su`, or `supg`) 546 - `none` 547 - 548 549* - `-c_tau` 550 - Stabilization constant, $c_\tau$ 551 - `0.5` 552 - 553 554* - `-Ctau_t` 555 - Stabilization time constant, $C_t$ 556 - `1.0` 557 - 558 559* - `-Ctau_v` 560 - Stabilization viscous constant, $C_v$ 561 - `36, 60, 128 for degree = 1, 2, 3` 562 - 563 564* - `-Ctau_C` 565 - Stabilization continuity constant, $C_c$ 566 - `1.0` 567 - 568 569* - `-Ctau_M` 570 - Stabilization momentum constant, $C_m$ 571 - `1.0` 572 - 573 574* - `-Ctau_E` 575 - Stabilization energy constant, $C_E$ 576 - `1.0` 577 - 578 579* - `-div_diff_flux_projection_method` 580 - Method used to calculate divergence of diffusive flux projection (`none`, `direct`, or `indirect`) 581 - `none` 582 - 583 584* - `-div_diff_flux_projection_ksp*` 585 - Control the KSP object for the projection of the divergence of diffusive flux 586 - N/A 587 - 588 589* - `-cv` 590 - Heat capacity at constant volume 591 - `717` 592 - `J/(kg K)` 593 594* - `-cp` 595 - Heat capacity at constant pressure 596 - `1004` 597 - `J/(kg K)` 598 599* - `-gravity` 600 - Gravitational acceleration vector 601 - `0,0,0` 602 - `m/s^2` 603 604* - `-lambda` 605 - Stokes hypothesis second viscosity coefficient 606 - `-2/3` 607 - 608 609* - `-mu` 610 - Shear dynamic viscosity coefficient 611 - `1.8e-5` 612 - `Pa s` 613 614* - `-k` 615 - Thermal conductivity 616 - `0.02638` 617 - `W/(m K)` 618 619* - `-newtonian_unit_tests` 620 - Developer option to test properties 621 - `false` 622 - boolean 623 624* - `-state_var` 625 - 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 $s = \ln(P\rho^{-\gamma})$ 626 - `conservative` 627 - string 628 629* - `-idl_decay_time` 630 - Characteristic timescale of the pressure deviance decay. The timestep is good starting point 631 - `-1` (disabled) 632 - `s` 633 634* - `-idl_start` 635 - Start of IDL in the x direction 636 - `0` 637 - `m` 638 639* - `-idl_length` 640 - Length of IDL in the positive x direction 641 - `0` 642 - `m` 643 644* - `-idl_pressure` 645 - Pressure used for IDL reference pressure 646 - `-reference_pressure` 647 - `Pa` 648 649* - `-sgs_model_type` 650 - Type of subgrid stress model to use. Currently only `data_driven` is available 651 - `none` 652 - string 653 654* - `-sgs_model_dd_leakyrelu_alpha` 655 - Slope parameter for Leaky ReLU activation function. `0` corresponds to normal ReLU 656 - 0 657 - 658 659* - `-sgs_model_dd_parameter_dir` 660 - Path to directory with data-driven model parameters (weights, biases, etc.) 661 - `./dd_sgs_parameters` 662 - string 663 664* - `-sgs_model_dd_model_implementation` 665 - Which computational implementation to use for SGS DD model (`fused`, `sequential_ceed`, `sequential_torch`) 666 - `fused` 667 - string 668 669* - `-sgs_model_dd_torch_model_path` 670 - Path to the PyTorch `*.pt` file containing the DD inference model 671 - 672 - string 673 674* - `-sgs_model_dd_torch_model_device` 675 - What hardware to perform the model inference on (`cpu`, `cuda`, `hip`, `xpu`) 676 - Default matches the libCEED backend 677 - string 678 679* - `-diff_filter_monitor` 680 - Enable differential filter TSMonitor 681 - `false` 682 - boolean 683 684* - `-diff_filter_grid_based_width` 685 - Use filter width based on the grid size 686 - `false` 687 - boolean 688 689* - `-diff_filter_width_scaling` 690 - Anisotropic scaling for filter width in wall-aligned coordinates (snz) 691 - `1,1,1` 692 - `m` 693 694* - `-diff_filter_kernel_scaling` 695 - Scaling to make differential kernel size equivalent to other filter kernels 696 - `0.1` 697 - `m^2` 698 699* - `-diff_filter_wall_damping_function` 700 - Damping function to use at the wall for anisotropic filtering (`none`, `van_driest`) 701 - `none` 702 - string 703 704* - `-diff_filter_wall_damping_constant` 705 - Constant for the wall-damping function. $A^+$ for `van_driest` damping function. 706 - 25 707 - 708 709* - `-diff_filter_friction_length` 710 - Friction length associated with the flow, $\delta_\nu$. Used in wall-damping functions 711 - 0 712 - `m` 713 714* - `-sgs_train_enable` 715 - Whether to enable *in situ* training of data-driven SGS model. Require building with SmartRedis. 716 - `false` 717 - boolean 718 719* - `-sgs_train_write_data_interval` 720 - Number of timesteps between writing training data into SmartRedis database 721 - `1` 722 - 723 724* - `-sgs_train_overwrite_data` 725 - Whether new training data should overwrite old data on database 726 - `true` 727 - boolean 728 729* - `-sgs_train_filter_widths` 730 - List of scalar values for different filter widths to calculate for training data 731 - 732 - `m` 733 734* - `-smartsim_collocated_num_ranks` 735 - Number of MPI ranks associated with each collocated database (i.e. ranks per node) 736 - `1` 737 - 738::: 739 740### Gaussian Wave 741 742The Gaussian wave problem has the following command-line options in addition to the Newtonian Ideal Gas options: 743 744:::{list-table} Gaussian Wave Runtime Options 745:header-rows: 1 746 747* - Option 748 - Description 749 - Default value 750 - Unit 751 752* - `-freestream_riemann` 753 - Riemann solver for boundaries (HLL or HLLC) 754 - `hllc` 755 - 756 757* - `-freestream_velocity` 758 - Freestream velocity vector 759 - `0,0,0` 760 - `m/s` 761 762* - `-freestream_temperature` 763 - Freestream temperature 764 - `288` 765 - `K` 766 767* - `-freestream_pressure` 768 - Freestream pressure 769 - `1.01e5` 770 - `Pa` 771 772* - `-epicenter` 773 - Coordinates of center of perturbation 774 - `0,0,0` 775 - `m` 776 777* - `-amplitude` 778 - Amplitude of the perturbation 779 - `0.1` 780 - 781 782* - `-width` 783 - Width parameter of the perturbation 784 - `0.002` 785 - `m` 786 787::: 788 789This problem can be run with the `examples/gaussianwave.yaml` file via: 790 791``` 792./build/navierstokes -options_file examples/gaussianwave.yaml 793``` 794 795```{literalinclude} ../examples/gaussianwave.yaml 796:language: yaml 797``` 798 799### Vortex Shedding - Flow past Cylinder 800 801The vortex shedding, flow past cylinder problem has the following command-line options in addition to the Newtonian Ideal Gas options: 802 803:::{list-table} Vortex Shedding Runtime Options 804:header-rows: 1 805 806* - Option 807 - Description 808 - Default value 809 - Unit 810 811* - `-freestream_velocity` 812 - Freestream velocity vector 813 - `0,0,0` 814 - `m/s` 815 816* - `-freestream_temperature` 817 - Freestream temperature 818 - `288` 819 - `K` 820 821* - `-freestream_pressure` 822 - Freestream pressure 823 - `1.01e5` 824 - `Pa` 825 826::: 827 828The initial condition is taken from `-reference_temperature` and `-reference_pressure`. 829To run this problem, first generate a mesh: 830 831```console 832$ make -C examples/meshes 833``` 834 835Then run by building the executable and running: 836 837```console 838$ make -j 839$ mpiexec -n 6 build/navierstokes -options_file examples/vortexshedding.yaml -{ts,snes}_monitor_ 840``` 841 842The vortex shedding period is roughly 5.6 and this problem runs until time 100 (2000 time steps). 843The 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. 844 845```console 846$ python postprocess/vortexshedding.py 847``` 848 849```{literalinclude} ../examples/vortexshedding.yaml 850:language: yaml 851``` 852 853### Density current 854 855The Density Current problem has the following command-line options in addition to the Newtonian Ideal Gas options: 856 857:::{list-table} Density Current Runtime Options 858:header-rows: 1 859 860* - Option 861 - Description 862 - Default value 863 - Unit 864 865* - `-center` 866 - Location of bubble center 867 - `(lx,ly,lz)/2` 868 - `(m,m,m)` 869 870* - `-dc_axis` 871 - Axis of density current cylindrical anomaly, or `(0,0,0)` for spherically symmetric 872 - `(0,0,0)` 873 - 874 875* - `-rc` 876 - Characteristic radius of thermal bubble 877 - `1000` 878 - `m` 879 880* - `-theta0` 881 - Reference potential temperature 882 - `300` 883 - `K` 884 885* - `-thetaC` 886 - Perturbation of potential temperature 887 - `-15` 888 - `K` 889 890* - `-P0` 891 - Atmospheric pressure 892 - `1E5` 893 - `Pa` 894 895* - `-N` 896 - Brunt-Vaisala frequency 897 - `0.01` 898 - `1/s` 899::: 900 901This problem can be run with: 902 903``` 904./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 75 905``` 906 907### Channel flow 908 909The Channel problem has the following command-line options in addition to the Newtonian Ideal Gas options: 910 911:::{list-table} Channel Runtime Options 912:header-rows: 1 913 914* - Option 915 - Description 916 - Default value 917 - Unit 918 919* - `-umax` 920 - Maximum/centerline velocity of the flow 921 - `10` 922 - `m/s` 923 924* - `-theta0` 925 - Reference potential temperature 926 - `300` 927 - `K` 928 929* - `-P0` 930 - Atmospheric pressure 931 - `1E5` 932 - `Pa` 933 934* - `-body_force_scale` 935 - Multiplier for body force (`-1` for flow reversal) 936 - 1 937 - 938::: 939 940This problem can be run with the `examples/channel.yaml` file via: 941 942``` 943./build/navierstokes -options_file examples/channel.yaml 944``` 945```{literalinclude} ../examples/channel.yaml 946:language: yaml 947``` 948 949(example-blasius)= 950 951### Blasius boundary layer 952 953The Blasius problem has the following command-line options in addition to the Newtonian Ideal Gas options: 954 955:::{list-table} Blasius Runtime Options 956:header-rows: 1 957 958* - Option 959 - Description 960 - Default value 961 - Unit 962 963* - `-velocity_infinity` 964 - Freestream velocity 965 - `40` 966 - `m/s` 967 968* - `-temperature_infinity` 969 - Freestream temperature 970 - `288` 971 - `K` 972 973* - `-pressure_infinity` 974 - Atmospheric pressure, also sets IDL reference pressure 975 - `1.01E5` 976 - `Pa` 977 978* - `-temperature_wall` 979 - Wall temperature 980 - `288` 981 - `K` 982 983* - `-delta0` 984 - Boundary layer height at the inflow 985 - `4.2e-3` 986 - `m` 987 988* - `-platemesh_modify_mesh` 989 - Whether to modify the mesh using the given options below. 990 - `false` 991 - 992 993* - `-platemesh_refine_height` 994 - Height at which `-platemesh_Ndelta` number of elements should refined into 995 - `5.9E-4` 996 - `m` 997 998* - `-platemesh_Ndelta` 999 - Number of elements to keep below `-platemesh_refine_height` 1000 - `45` 1001 - 1002 1003* - `-platemesh_growth` 1004 - Growth rate of the elements in the refinement region 1005 - `1.08` 1006 - 1007 1008* - `-platemesh_top_angle` 1009 - Downward angle of the top face of the domain. This face serves as an outlet. 1010 - `5` 1011 - `degrees` 1012 1013* - `-platemesh_y_node_locs_path` 1014 - Path to file with y node locations. If empty, will use mesh warping instead. 1015 - `""` 1016 - 1017 1018* - `-stg_use` 1019 - Whether to use STG for the inflow conditions 1020 - `false` 1021 - 1022 1023* - `-n_chebyshev` 1024 - Number of Chebyshev terms 1025 - `20` 1026 - 1027 1028* - `-chebyshev_` 1029 - Prefix for Chebyshev snes solve 1030 - 1031 - 1032 1033::: 1034 1035This problem can be run with the `examples/blasius.yaml` file via: 1036 1037``` 1038./build/navierstokes -options_file examples/blasius.yaml 1039``` 1040 1041```{literalinclude} ../examples/blasius.yaml 1042:language: yaml 1043``` 1044 1045### STG Inflow for Flat Plate 1046 1047Using the STG Inflow for the blasius problem adds the following command-line options: 1048 1049:::{list-table} Blasius Runtime Options 1050:header-rows: 1 1051 1052* - Option 1053 - Description 1054 - Default value 1055 - Unit 1056 1057* - `-stg_inflow_path` 1058 - Path to the STGInflow file 1059 - `./STGInflow.dat` 1060 - 1061 1062* - `-stg_rand_path` 1063 - Path to the STGRand file 1064 - `./STGRand.dat` 1065 - 1066 1067* - `-stg_alpha` 1068 - Growth rate of the wavemodes 1069 - `1.01` 1070 - 1071 1072* - `-stg_u0` 1073 - Convective velocity, $U_0$ 1074 - `0.0` 1075 - `m/s` 1076 1077* - `-stg_mean_only` 1078 - Only impose the mean velocity (no fluctutations) 1079 - `false` 1080 - 1081 1082* - `-stg_strong` 1083 - Strongly enforce the STG inflow boundary condition 1084 - `false` 1085 - 1086 1087* - `-stg_fluctuating_IC` 1088 - "Extrude" the fluctuations through the domain as an initial condition 1089 - `false` 1090 - 1091 1092* - `-stg_dx` 1093 - Set the element size in the x direction. Default is calculated for box meshes, assuming equispaced elements. 1094 - 1095 - `m` 1096 1097* - `-stg_h_scale_factor` 1098 - Scale element size for cutoff frequency calculation 1099 - $1/p$ 1100 - 1101 1102::: 1103 1104This problem can be run with the `examples/blasius.yaml` file via: 1105 1106``` 1107./build/navierstokes -options_file examples/blasius.yaml -stg_use true 1108``` 1109 1110Note the added `-stg_use true` flag 1111This overrides the `stg: use: false` setting in the `examples/blasius.yaml` file, enabling the use of the STG inflow. 1112