Hi Peter,
we are definitely not related. But several of my people changed name when they came from Germany to the States from Juengel to Yuengel, due to differences in pronounciation. I wonder where your name could come from. A Yuengel does certainly not exist in Germany, however you will find a couple of Juenger (German spelling: Junger with "Umlaut")here.
Good luck
Juergen Juengel
Germany