run two simulations on the same computer

I have access to a system that has two GPUs. We also have access to multiple simulations licenses. Is there anyway I can set up two simulations to run at the same time? One simulation would be using GPU0 and the other would be using GPU1? (I also know how to set what gpu each simulation will run)
Currently, only one simulation will run and the next simulation that should be able to run at the same time is stuck in the ares que until the first simulation finishes.