test about nasa0714

[paipaizhu]

Hi:

Recently，I want to run a test, but running speed is slow,i do not know why.here is my inputfile.can you help me explain it.the amount of grid is 40000,First layer grid height is 1E-6.

Solver parameters

// 0: Euler/Navier-Stokes, 1:Advection/Adv-Diffusion equation 0 viscous 1

// 0: Rusanov, 1: Lax-Friedrich, 2: Roe riemann_solve_type 0 vis_riemann_solve_type 0

// 0: Isentropic Vortex, 1: Uniform flow, 2: Sine Wave ic_form 1

// 0: Normal (doesn't have an analytical solution), 1:Isentropic Vortex, 2: Advection-Equation test_case 0 order 3 // Order of basis polynomials dt_type 1 // 0: User-supplied, 1: Global, 2: Local dt 0.0001 CFL 0.01 n_steps 100000000 adv_type 3 // 0: Forward Euler, 3: RK45 tau 1.0 pen_fact 0.5 turb_model 1

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Mesh options

mesh_file nasa0714.neu

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Monitoring, plotting parameters

p_res 6 // Plotting resolution, # of nodes per direction write_type 1 // 0: Paraview, 1: Tecplot volume_cub_order 12 // Order of cubature rule for integrating over element volumes

monitor_res_freq 100 plot_freq 1000 data_file_name invCyl restart_dump_freq 100000 diagnostic_fields 6 u v w energy pressure mach res_norm_type 1 // 1:L1 norm, 2:L2 norm, 0:infinity norm error_norm_type 1 // 1:L1 norm, 2:L2 norm, 0:infinity norm res_norm_field 0 // Density

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Element parameters

==== Tris ==== upts_type_tri 0 fpts_type_tri 0 vcjh_scheme_tri 3 c_tri 0.0 sparse_tri 0

==== Quads ==== upts_type_quad 0 // 0: Gauss, 1: Gauss-Lobatto vcjh_schemequad 3 // 0: VCJH, 1: DG, 2: SD, 3: Hu, 4: c+ eta_quad 0.0 sparse_quad 0

==== Hexs ==== upts_type_hexa 0 vcjh_scheme_hexa 0 eta_hexa 0. sparse_hexa 0

==== Tets ==== upts_type_tet 1 fpts_type_tet 0 vcjh_scheme_tet 0 eta_tet 0.0 sparse_tet 0

==== Prisms ==== upts_type_pri_tri 0 upts_type_pri_1d 0 vcjh_scheme_pri_1d 0 eta_pri 0.0 sparse_pri 0

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Fluid Parameters

gamma 1.4 prandtl 0.72 S_gas 120. T_gas 291.15 R_gas 286.9 mu_gas 1.827E-05

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Boundary conditions

==== Viscous ==== fix_vis 0 // 0: Sutherland's law, 1: Constant viscosity Mach_free_stream 0.724 nx_free_stream 1. ny_free_stream 0. nz_free_stream 0. Re_free_stream 1000000. L_free_stream 1. T_free_stream 300 T_wall 300 Mach_wall 0. nx_wall 1. ny_wall 0. nz_wall 0. T_wall 300

==== Inviscid ==== rho_bound 1. u_bound 1.0 v_bound 1.0 w_bound 0.0 p_bound 17.857142857142854098

[JacobCrabill]

Hi,

Could you explain what you mean by the code running slowly so we can help you diagnose any issues you may be having?

-Jacob

[paipaizhu]

Hi Jacobraill, I have already know why the code running is slow.as for large Re,we have to add the amount of mesh in boundary layer.then dt(dt_type=0) become smaller.I set it to 10E-9.and the Res is large.it will take lots of time to calculate. so what i can do to derease the calculate time? Best regards

[JacobCrabill]

HiFiLES does not have any steady-state convergence acceleration methods implemented at this time; the only change you could potentially make to your input file is to change "vcjhscheme*" to 4, which modifies the correction functions to David William's "C_+" scheme, which has the highest CFL limit out of all available methods.

Another thing you could do is to first run the simulation with 1st-order polynomials ("order 1"), which will allow you to generate a converged simulation much more quickly, and then restart your simulation at a higher order, using the lower-order solution as the initial condition.

Lastly, although 40,000 elements is a very large number of elements to resolve a 2D geometry, if the wall boundaries of your mesh are represented by linear elements (as opposed quadratic or higher curved triangles/quads), the sharp corners between elements can create issues that impair convergence.