友好交往源远流长 friendly exchanges date back to ancient times

源远流长 long-standing and well-established ; run a long history ; UNIX ; but realized with the mind

秋水流长 The Running Water in Fall

湍流长度尺度 length scale ; turbulence length scale

射流长度 jet length

串流长度 stream length

流长度 Length of the stream

节流长度 [机] choke length ; length of restriction ; restrictive length ; throttling length

水流长度 Flow Length