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French to English translations [PRO] Science - Mechanics / Mech Engineering / Fluid mechanics
French term or phrase:écoulements instationnaires
"le domaine de l’analyse, la modélisation et le contrôle des écoulements instationnaires (application au contrôle des écoulements instables)."
My immediate thought was "unsteady flows", but I then got 68 google hits for "unstationary flows". Are these two different things, or is "unstationary" a mistranslation? Any expert help much appreciated!
Explanation: This has been discussed here in the past. If the past discussion is not retrievable, here's something from Kiwipedia:
Instationnaire Instationary, non-stationary, non-permanent, unsteady (varying, not regular or cyclic) Instationnaire, mouvements Vibratory behaviour, stall flutter Instationnaire, système Hydroelastic system
-------------------------------------------------- Note added at 2 hrs (2010-03-11 15:38:29 GMT) --------------------------------------------------
"Flutter" (possibly qualified by something), presumably, since you're dealing with flow.
FLUTTER can occur in any object within a STRONG FLUID FLOW, under the conditions that a positive feedback occurs between the ...
en.wikipedia.org/wiki/Aeroelasticity
The theoretical model of 3D FLUTTER in subsonic, transonic and supersonic inviscid FLOW. Transaction of the Institute of Fluid-Flow Machinery 106 ...
linkinghub.elsevier.com/retrieve/pii/S0022460X01939811
The type and the degree of separation on the HYDROFOIL exert much influence on the UNSTEADY FLUID FORCE and the FLUTTER boundary in the subcavitation region ...
ci.nii.ac.jp/naid/110002981570/en
The origin of such FLUTTER is usually attributed to AN OSCILLATORY INSTABILITY OF A STEADY STATE when the FLUID FLOW exceeds a threshold, and is referred to as an instance of a Poincare–Andronov–Hopf (PAH) bifurcation....
rspa.royalsocietypublishing.org/content/early/.../rspa.2009.0328.full.html http://www.seas.harvard.edu/softmat/downloads/2009-12.pdf
Thank you, Chris, for this extremely clear explanation! It is not the first time you have helped me out; I much appreciate it.
Am I correct in using "unstable flows" for "écoulements instables"?
Unsteady and non-stationary flows are not quite the same thing. An unsteady flow, ie not constant, can be stochastically "stationary". Stationarity in a stochastic sense means that if you take a random sample of finite length at any time, it will be statistically the same from one sample to the next, eg the sound of a trickling stream. A non stationary signal might be a 5 minute sample of a soap opera. A jet exhaust is unsteady, but is stationary (in the stochastic sense).
I should stick with non-stationary. "Unstationary" is not often used in "respectable" literature.
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Answers
1 hr confidence:
for variety's sake
Explanation: This has been discussed here in the past. If the past discussion is not retrievable, here's something from Kiwipedia:
Instationnaire Instationary, non-stationary, non-permanent, unsteady (varying, not regular or cyclic) Instationnaire, mouvements Vibratory behaviour, stall flutter Instationnaire, système Hydroelastic system
-------------------------------------------------- Note added at 2 hrs (2010-03-11 15:38:29 GMT) --------------------------------------------------
"Flutter" (possibly qualified by something), presumably, since you're dealing with flow.
FLUTTER can occur in any object within a STRONG FLUID FLOW, under the conditions that a positive feedback occurs between the ...
en.wikipedia.org/wiki/Aeroelasticity
The theoretical model of 3D FLUTTER in subsonic, transonic and supersonic inviscid FLOW. Transaction of the Institute of Fluid-Flow Machinery 106 ...
linkinghub.elsevier.com/retrieve/pii/S0022460X01939811
The type and the degree of separation on the HYDROFOIL exert much influence on the UNSTEADY FLUID FORCE and the FLUTTER boundary in the subcavitation region ...
ci.nii.ac.jp/naid/110002981570/en
The origin of such FLUTTER is usually attributed to AN OSCILLATORY INSTABILITY OF A STEADY STATE when the FLUID FLOW exceeds a threshold, and is referred to as an instance of a Poincare–Andronov–Hopf (PAH) bifurcation....
rspa.royalsocietypublishing.org/content/early/.../rspa.2009.0328.full.html http://www.seas.harvard.edu/softmat/downloads/2009-12.pdf
xxxBourth Local time: 20:48 Specializes in field Native speaker of: English PRO pts in category: 802
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