There is an online video game called War Thunder that lets you fly various planes from roughly the 30s to the late 50s. It has some pretty detailed models, and I've noticed these lumps on the wings of many planes. The planes are partly modelled on the interior and can be seen in what's called X-ray view. I've noticed that many of these lumps are placed right above where the base of the plane's gun/cannon is. This has led me to believe that they might be placed in these positions to cool the guns as air is swept over these lumps. But it turns out that in many cases these lumps aren't placed where the guns are and seem not to have this purpose. Here are some pictures of what I've talking about, I have circled them in black.
Examples of where they appear over the guns:
Hawker Tempest MkII
Brewster F2A Buffalo
Examples where these lump wing features don't appear above the gun/cannon:
Grumman F4F Wildcat
de Havilland Venom
Note that the last two planes are jets and have their guns mounted completely in the centre of the plane, on the nose (ie., there are no guns in the wings). Also, I've noticed that for planes that have no guns mounted in the wings only British planes (in the game) have these, namely the two jets.
I'm am wondering what the function of these things are, and what they are called, if anything? Do they serve an aerodynamic function or are they maybe to cool other parts within the wing?