If you run the model by double-clicking on it or selecting Run from a menu or a button, then the outputs will go into the base workspace. If you are at the command line, you can see what is in the base workspace by entering the command
to open the workspace browser.
If, instead, the model is being controlled by a MATLAB function which is making sim() calls, then the output will go into the workspace of the function that makes the calls. To see that output you would need to put a breakpoint in the function and use the workspace browser to examine the function's workspace.