So I have encountered a dragon in the hinterlands that starts flying around as soon as I enter the area.

I can't really attack it or force it to land, and then after a while it flies away.

Do these dragons ever return to the locations at which they spawn? :/ Or is there anything else I should know about these encounters to ensure I can attempt them again, if possible?

It will always be there until you kill it. Once you kill it, it will never come back. The one you are talking about flys farther back into the area and lands. You have to fight it there. Its level 12 and very strong. And summons dragonlings to fight with it. So don't go in there unless your level 12 and have good fire resistant gear.