Timeline for Why do turbofan blade tips exceed the speed of sound while prop tips should not?
Current License: CC BY-SA 3.0
12 events
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| Apr 13, 2017 at 12:59 | history | edited | CommunityBot |
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| Sep 27, 2016 at 17:10 | history | protected | CommunityBot | ||
| Oct 26, 2015 at 19:16 | vote | accept | FreeMan | ||
| Oct 24, 2015 at 0:06 | comment | added | reirab | @alephzero The blade tips are traveling in a plane that is (mostly) perpendicular to the flow through the engine. It's true that the flow through the engine will usually (probably always in a non-scramjet) be subsonic, but that doesn't mean the blade tips are subsonic relative to the air in which they're traveling, since they're moving perpendicular to said flow. In order for the airspeed of the blade tips to be less than their rotational speed, the intake air would have to be rotating around the turbine axis before encountering the intake fan. | |
| Oct 23, 2015 at 22:30 | comment | added | alephzero | The Mach 1.67 estimate is too high, because it ignores the fact that the airflow through the fan is constrained by the fan case. The speed difference between the blade tips and the air outside the fan case is irrelevant. The flow through the fan is indeed transonic in some situations, but the highest Mach number is much closer to 1.0 than to 1.67. | |
| Oct 23, 2015 at 22:26 | answer | added | alephzero | timeline score: 10 | |
| Oct 23, 2015 at 18:02 | history | tweeted | twitter.com/StackAviation/status/657618200868364288 | ||
| Oct 23, 2015 at 16:20 | answer | added | Robert Werner | timeline score: 8 | |
| Oct 23, 2015 at 15:19 | answer | added | aeroalias | timeline score: 14 | |
| Oct 23, 2015 at 14:32 | history | edited | FreeMan | CC BY-SA 3.0 |
edited title
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| Oct 23, 2015 at 14:11 | answer | added | Peter Kämpf | timeline score: 28 | |
| Oct 23, 2015 at 13:46 | history | asked | FreeMan | CC BY-SA 3.0 |