资料来源 : pyDict

无旋的

资料来源 : Webster's Revised Unabridged Dictionary (1913)

Irrotational \Ir`ro*ta"tion*al\, a. (Physics)
   Not rotatory; passing from one point to another by a movement
   other than rotation; -- said of the movement of parts of a
   liquid or yielding mass. --Sir W. Thomson.