So 駆逐艦 means destroyer, I'm guessing 円陽 is the name here (not too sure on 円, since it really shouldn't extend on the right and left like it does here), and it's certainly not a name that seems to be recognized anywhere. Any ideas?
depending on the language and the writing, it may have different meaning. What you wrote was Yan, the Japanese currency unit. by the way, the second word means sun. I think the actual writing is a bit different since it has the horizontal line extended, and as such it looks like one of the chinese characters, which refers to a single, round object. If so then the two words together would refer to the sun. Japanese flag perhaps?
1. This has been here for 2 years already, it's not like I just posted it.
2. it's not Yan, it's "Yen"
3. "円" in the context of ships usually means Maru (literally circle, like you mentioned) which is a common suffix for ships, but I'm not sure that it is here since it's not being used on it's own.
"陽" does mean sun, and also day, but "Sun" in japanese is "太陽".
"Enyou"? "Enyo" was a Greek goddess of warfare, but no wartime destroyer bore a name anthing like that. "12" was the hull number of the Fubuki-class destroyer "Shirakumo". The raked stacks look more like a Nihon Kaigun heavy cruiser. I'm throwing things at this, but nothing seems to stick. Artistic liberties in extremis?
This is Kagerou-class destroyer "Yukikaze". In the post-war period, she was ceded to the Republic of China as a war reparation, and renamed "DD-12 丹陽(Tang Yan)".