Results:

.. image:: ../../../data/conv_test_niter_NS3.png
   :width: 19%

.. image:: ../../../data/conv_test_niter_NS2.png
   :width: 19%

.. image:: ../../../data/conv_test_niter_Linf_diffusion.png
   :width: 19%

.. image:: ../../../data/conv_test_niter_Linf_advection.png
   :width: 19%

