Blender does physics simulation, but it's extremely fiddly. It changes every single time you run it which means if you want a specific look, you're going to lose days of your life trying to accomplish it. But the good news is all you have to do is put pieces of your explosion where you want them to start, set some mass and gravity settings, then hit play. All the really hard work it does for you.
I've done basically nothing but that since September.. though a lot of it was teaching myself the limitations of Blender's physics features.