However only steady and mean flow state have been studied for a long period of time.

在很长的一段时间内，人们对上述流态的了解仅限于定常的或时间平均的流态。

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However only steady and mean flow state have been studied for a long period of time.

在很长的一段时间内，人们对上述流态的了解仅限于定常的或时间平均的流态。

youdao