You can run the model without opening the model using the sim command. See doc for sim command here. You can also load the model using load_system which will load the model in memory but not open the editor. See Run Simulations Programmatically for more details.
The following will load the Modeling a Fault-Tolerant Fuel Control System example model (sldemo_fuelsys) and simulate it:
model = 'sldemo_fuelsys';
load_system(model);
set_param(model, 'SimulationCommand', 'start')
You can simulate it without opening/loading explicitly using the following:
sim('sldemo_fuelsys')
