From: firstname.lastname@example.org (JVRusso) Organization: America Online, Inc. (1-800-827-6364) Date: 20 Jul 96 15:56:05 References: 1 Followups: 1
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On 7 July, email@example.com (Wolfgang Wohlers) wrote: :I will try, though I am not sure about it: Today turbofans have bypass :ratios of about 7. If you say that the change in velocity is about the :same for bypass and core air (this is not exact of course) you get 7/8 :of the thrust through the bypass and 1/8 thruogh the core air. I am :not sure how much faster the core air is, but I think most the thrust :is provided by the bypass air. Actually, bypass ratio is a measure of airflow, not thrust. For example, on a turbofan with a BPR of 1.0, for every 1# of air that goes thru the core, 1# bypasses it. A BPR of 2.0 means 2# bypass for every 1# in the core, etc. (a BPR of 0 would mena a turbo jet, but that term isn't really used in discussion). The big turbofans run with BPRs of 8 or more, while the military jets generally range from 0.2 to 0.8, depending on the design.