R,

I was getting an error while running the example.
./simple.py examples/navier_stokes/navier_stokes2d.py
sfepy: left over: ['data_dir', 'verbose', '_filename', '__builtins__', '__package__', '__doc__', '__name__', '__file__']
sfepy: reading mesh (/home/ankit/sfepy/meshes/2d/rectangle_fine_quad.mesh)...
sfepy: ...done in 0.02 s
sfepy: creating regions...
sfepy:     Right
sfepy:     Bottom
sfepy:     Top
sfepy:     Surface
sfepy:     Omega
sfepy:     Walls
sfepy:     Driven
sfepy: ...done in 0.03 s
sfepy: equation "balance":
sfepy: + dw_div_grad.5.Omega(fluid.viscosity, v, u)
       + dw_convect.5.Omega(v, u)
       - dw_stokes.5.Omega(v, p) = 0
sfepy: equation "incompressibility":
sfepy: dw_stokes.5.Omega(u, q) = 0
sfepy: setting up dof connectivities...
sfepy: ...done in 0.00 s
sfepy: using solvers:
                ts: no ts
               nls: newton
                ls: ls
sfepy: updating variables...
sfepy: ...done
sfepy: matrix shape: (44557, 44557)
sfepy: assembling matrix graph...
sfepy: ...done in 0.13 s
sfepy: matrix structural nonzeros: 1728264 (8.71e-04% fill)
sfepy: updating materials...
sfepy:     fluid
sfepy: ...done in 0.01 s
sfepy: nls: iter: 0, residual: 2.023986e-02 (rel: 1.000000e+00)
convect_build_vtg(): ERR_Switch
mem_free_mem(): error exit!
mem_free_mem(): error exit!
mem_free_mem(): error exit!
mem_free_mem(): error exit!
mem_free_mem(): error exit!
mem_free_mem(): error exit!
mem_free_mem(): error exit!
mem_free_mem(): error exit!
Traceback (most recent call last):
File "./simple.py", line 146, in <module>
    main()
File "./simple.py", line 143, in main
    app()
File "/home/ankit/sfepy/sfepy/applications/application.py", line 29, in call_basic
    return self.call(**kwargs)
File "/home/ankit/sfepy/sfepy/applications/pde_solver_app.py", line 213, in call
    nls_status=nls_status)
File "/home/ankit/sfepy/sfepy/solvers/ts_solvers.py", line 29, in __call__
    state = problem.solve(state0=state0, nls_status=nls_status)
File "/home/ankit/sfepy/sfepy/fem/problemDef.py", line 933, in solve
    vec = solvers.nls(vec0)
File "/home/ankit/sfepy/sfepy/solvers/nls.py", line 345, in __call__
    mtx_a = fun_grad(vec_x)
File "/home/ankit/sfepy/sfepy/fem/evaluate.py", line 66, in eval_tangent_matrix
    mtx = pb.equations.eval_tangent_matrices(vec, mtx)
File "/home/ankit/sfepy/sfepy/fem/equations.py", line 640, in eval_tangent_matrices
    self.evaluate(mode='weak', dw_mode='matrix', asm_obj=tangent_matrix)
File "/home/ankit/sfepy/sfepy/fem/equations.py", line 526, in evaluate
    asm_obj=asm_obj)
File "/home/ankit/sfepy/sfepy/fem/equations.py", line 766, in evaluate
    ret_status=True)
File "/home/ankit/sfepy/sfepy/terms/terms.py", line 1473, in evaluate
    diff_var, **kwargs)
File "/home/ankit/sfepy/sfepy/terms/terms.py", line 1311, in eval_real
    status = self.call_function(out, fargs)
File "/home/ankit/sfepy/sfepy/terms/terms.py", line 1296, in call_function
    raise ValueError('term evaluation failed! (%s)' % self.name)
ValueError: term evaluation failed! (dw_convect)

Regards,
Ankit

PS: I was not aware that we have to blog weekly. I will blog for week 1 and 2 asap.

On Tuesday, 2 July 2013 13:58:20 UTC+5:30, Robert Cimrman wrote:

Now it remains to implement a robust flow solver. Even this small example
shows, that the solution is not obtained easily - try decreasing the viscosity,
and/or increase the Dirichlet velocity - the solver would not converge.

Cheers,
r.
PS: As mentioned in Terri Oda's e-mail, you should blog about your work so far
ASAP!

On 07/01/2013 06:12 PM, Ankit Mahato wrote:
> awesome :)
>
> On Monday, 1 July 2013 15:05:16 UTC+5:30, Robert Cimrman wrote:
>>
>> Hi,
>>
>> I have removed the "3d only" restriction from the Navier Stokes and
>> related
>> terms. There is also a new example:
>> examples/navier_stokes/navier_stokes2d.py.
>>
>> r.
>>
>