HI Adeyemi,
The easiest thing to do is to use a Variable Local Restriction and closes it when you want the blockage to occur. You can use a time-varying signal (like a step) to generate a sudden closure of the restriction, i.e. blockage.
You'll probably notice that this is not TOTAL blockage as the restriction has a minimum leakage area. This minimum area is both realistic and numerically necessary. No blockage has absolutely zero leakage. And to totally break the connect at a point means a different set of equations for your system. This requires Simscape to recompile all the equations and solve a different set of equations, which cannot be done within one single simulation. So, just make the leakage area reasonable small (not crazy small) so that the leakage flow doesn't make any practical difference.
