I was going through tor to see what I could see, and I came across and answered this question which asks about Mac OS X:
How do I tell tor, from the command-line, to give me a new identity
Further down, I came across what I think is essentially the same question, but phrased differently, and asking about Linux:
Initially I was going to flag as a dupe. But, I think the different phrasing and operating systems involved may mean that there is some value in having both questions open, perhaps linked to each other in the comments.
On the other hand, we could edit the second question a bit to ask about POSIX-compatible OSs and include the two different phrases ("New identity", "flush circuit") though this would do some violence to the OP's actual question.
What do you think that we should do here?