渦動 is read as かどう (kadou) and means vortex.
かどう
kadou
うずまき
spiral (shape, pattern)
かちゅう
vortex
うず
whirlpool
うずまく
to be all jumbled together (feelings, thoughts, etc.)
かじょうもん
spiral pattern
うずでんりゅう
eddy current
かじょうぎんが
spiral galaxy
うずけいしき
vortex design
うずまきぎんが
げきどう
violent shock
いどう
(personnel) change
しんどう
oscillation