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ESDU Challenge: Acenaphthene

Posted March 13, 2015 12:00 AM by SavvyExacta
Pathfinder Tags: ESDU esdu challenge

In this series from IHS ESDU, challenge questions will be posted for the community. Some questions may require calculations and others are general knowledge questions.

Here's this week's question:

The use of oil flow visualisation as a means of identifying flow features can be a valuable tool to aid the analysis of the aerodynamic characteristics of a configuration. In this process, acenaphthene is used to:

a) show boundary layer transition in low-speed tests by evaporation

b) show boundary layer transition in high-speed tests by sublimation

c) show flow direction near the model surface by streaking


Check back soon for the solution to this question! Visit the IHS ESDU website for more information about the validated design methods, or to request a trial subscription.

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#1

Re: ESDU Challenge: Acenaphthene

03/13/2015 7:58 AM

If there were a question in there, I'd say that the answer was b) - sublimation.

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#3
In reply to #1

Re: ESDU Challenge: Acenaphthene

03/13/2015 11:51 AM

"Acenapthene sublimation is a standard visualisation technique used in the ARA Transonic Wind Tunnel (TWT) to detect the position of transition from laminar to turbulent flow on the model surface"

Source: http://www.ara.co.uk/services/experimental-aerodynamics/optical-systems/acenaphthene-sublimation/

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#2

Re: ESDU Challenge: Acenaphthene

03/13/2015 11:42 AM

C)- Flow visualisation by streaking.

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#4

Re: ESDU Challenge: Acenaphthene

03/13/2015 12:18 PM

"Acenaphthene is a hydrocarbon component of tar. An acenaphthene film spread over the wing has the property of being "ripped off" (we say that it is sublimated) when the flow is turbulent, which helps to differentiate the laminar areas (white) from the turbulent areas (black), with the boundary characterizing the transition."

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#5

Re: ESDU Challenge: Acenaphthene

03/13/2015 5:01 PM

Acenaphthene should only be taken under the close supervision of a psychiatrist.

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#6
In reply to #5

Re: ESDU Challenge: Acenaphthene

03/13/2015 11:38 PM

should be a "Like" button,,, had a good laugh, thanks

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#7
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Re: ESDU Challenge: Acenaphthene

03/13/2015 11:40 PM

Maybe an "irreverent" button?

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