Give correct and clear answer. Otherwise I will downvote. Model this using espresso software. No other software.

11:50 f Yo 49 1 .| 12% dary conditions will fully specify the velocity solution, but for some combinations of geor conditions the solution will still be underdetermined. In the language of linear algebra, may have a nullspace. lly the user will be able to determine beforehand whether their problem has a nullspace. F in a spherical shell geometry with free-slip boundary conditions at the top and bottom dy rotation in its nullspace (but not translations, as the boundary conditions do not them). That is to say, the solver may be able to come up with a solution to the Stoke solution plus an arbitrary rotation is also an equally valid solution. er example is a model in a Cartesian box with periodic boundary conditions in the slip boundaries on the top and bottom. This setup has arbitrary translations along th ace, so any solution plus an arbitrary x-translation is also a solution. ition with some small power in these nullspace modes should not affect the physics of the the timestepping of the model is based on evaluating the maximum velocities in the sol nnecessary motions can severely shorten the time steps that ASPECT takes. Further tions can make postprocessing calculations and visualization more difficult to interpret. ECT allows the user to specify if their model has a nullspace. If so, any power in the n d and removed from the solution after every timestep. There are two varieties of nullspa nted: removing net linear/angular momentum, and removing net translations/rotations. 39 Example of nullspace removal. On the left the nullspace (a rigid rotation) is remove rectors accurately show the mantle flow. On the right there is a significant clockwise rot solution which is making the more interesting flow features difficult to see. emoving linear momentum we search for a constant velocity vector c such that p ( u - C ) = 0 may be solved by realizing that S, pu = p, the linear momentum, and Sop = M, the to 1. Then we find C = P/M subtracted off of the velocity solution. ving the angular momentum is similar, though a bit more complicated. We search for such that O