Manuel Valera <mvaler...@sdsu.edu> writes: > Thanks for the answer, I will read the mentioned example, but to clarify > for Barry I will schematize the process: > > At time n, the program need to do all of these at once: > > 1. Solve T as a function of u,v,w > 2. Solve S as a function of u,v,w > 3. Solve rho density as a function of T,S > 4. Derivate a correction of the velocity fields from the density > 5. Solve u,v,w being corrected by the density field > > What I have implemented so far: > > 1. Advance TS1 to solve for T > 2. Advance TS2 to solve for S > 3. Solve rho and calculate correction > 4. Advance TS3 to solve for u,v,w > > Or, altenatively: > > 1. Advance TS to solve for T,S,u,v,w at the same time. > 2. Solve rho and calculate correction > > Both implementation are lacking the feedback from the T,S <-> rho <-> > Velocities interaction, and is creating problems when using a bigger DT. > > All the systems from the first numeration are different algorithms, and > each TS in the 2nd numeration generate a different RHS. > > What Jed is suggesting is to create an overarching routine that does all > that is the first list under one single step?
TSSSP isn't SSP or high order with ad-hoc coupling procedures such as the above. If you're in a parameter regime that is stiff (e.g., typical regime in which barotropic splitting is popular), I would suggest putting the semi-implicit component into a preconditioner or Rosenbrock-W Jacobian approximation so that you can preserve the desirable accuracy and stability properties of the method.