Contrails Simulation in a tunnel

[Spooner]

Hi everyone

I would like to know your opinion if it will posibble to promote contrails inside a tunnel with atmospheric pressure, -30ºC, 120RH and a pipe from a diesel engine exhaust in the centre for get soot.

I know that it sounds crazy, but the conditions are very close to Appleman criterion, also I've read over 30 references and I haven't found anything

So, what do you think?

 

[Jay Reynolds]

Hi everyone

I would like to know your opinion if it will posibble to promote contrails inside a tunnel with atmospheric pressure, -30ºC, 120RH and a pipe from a diesel engine exhaust in the centre for get soot.

I know that it sounds crazy, but the conditions are very close to Appleman criterion, also I've read over 30 references and I haven't found anything

So, what do you think?

You need relative humidity with respect to ice in supersaturation and below -40C to get persistence, but only -40C to get the contrail to form.

 

[FreiZeitGeist]

I would like to know your opinion if it will posibble to promote contrails inside a tunnel with atmospheric pressure, -30ºC, 120RH and a pipe from a diesel engine exhaust in the centre for get soot.

In sibira or alaska, you dont need a tunnel (except for the presure)






Short Video of a starting airplane making a contrail:
http://dl.avsim.su/video/47644.mp4

 

[Spooner]

Mi objetive is promote visible contrails, but my tunnel only can achieve -30ºC with supersaturated respect to ice...I don't really know how strict is Appleman's Criterion...

 

[Spooner]

FreiZeitGeist thanks for your thoughts, but my thesis is doing this stuff in the tunnel

 

[David Fraser]

I cant be arsed to access the main article but is this helpful?? http://adsabs.harvard.edu/abs/2011ACPD...1126791W

 

[Spooner]

I only have this tunnel for promoting contrails and this is the objective of my MSc thesis

http://www.cranfield.ac.uk/soe/facilities/page11097.html

this is the reason why I've posted the question, I would like to know if there is other people woldwide who have already promoted contrail formation

thanks for the help, [...]

 

[Spooner]

thanks Biggerdave, I'll read it, it seems to be usefull

 

[Spooner]

Dr. Tanner's expertise is unmatched. He has a global operation and if you can make a contrail, or even if you can't, he can detect it.

thanks, I'm the first in my university studying this issue and sometimes its difficult to get information to compare my research, [...]

 

[David Fraser]

thanks, I'm the first in my university studying this issue and sometimes its difficult to get information to compare my research, hopefully Dr Russ Tanner help me, I've sent a Fb

I contacted a friend who I have recently been talking with via FB. The smartarse apparently works on wing design for BAe. His advice was contact FAAM which is at your place I think. The only advice he did give was look carefully at what fuel you use in the lab. Paraffin is the closest you will get to act like aviation fuel.

 

[Jay Reynolds]

[...] I would try contacting some of the researchers who have published papers on critical temperatures for contrail formation, etc.

FAAM has a long history of contrail research. [...]

 

[Spooner]

I contacted a friend who I have recently been talking with via FB. The smartarse apparently works on wing design for BAe. His advice was contact FAAM which is at your place I think. The only advice he did give was look carefully at what fuel you use in the lab. Paraffin is the closest you will get to act like aviation fuel.

Thanks! I didn't know about this Facility, I'll put in contact because they are in my university.

 

[Spooner]

Hi! I have one more question, does anyone have the Appleman's original document "the formation of exhaust condensation trails by jet aircraft" written in 1953? cause I can't find it

Finally contrails formation is not feasible in this tunnel (because I need at least -40 ºC) and I'm studying some modifications for get this phenomenon...Thank you all for your knowledge, I'm learning a lot of stuff reading this forum.

Actually I'm thinking about insert a scaled engine and promote contrails with a soot generator, this photo is one of my designs.


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[Mick West]

I have removed unhelpful references to Russ Tanner. Please avoid in-jokes in what appears to be a serious question, even if you don't think it is. They just confuse people.

 

[David Fraser]

With all due respect mate but you are a postgraduate student with all the resources of Cranfield, and the online resources. I have just checked and I can access a copy at my former uni (I still have reading rights). I would ask around uni or put a British Library request in.

 

[Ross Marsden]

In this scientific paper about contrails and the required meteorological conditions for formation and persistence,
"Calculations of Aircraft Contrail Formation Critical Temperatures" by Mark L. Schrader, a mathematical relationship is derived that enables you to find the Critical Temperature for contrail formation. When the ambient temperature is lower than the Critical Temperature you will have a contrail. The problem is the selection of CF, the Contrail Factor. You can probably use 0.0336 g/kg/K (Appleman's figure) and use a petrol engine running under load to simulate jet engine exhaust at cruise. That will have all the condensation and freezing nuclei you need.
Since you are operating at surface pressure about 1000 hPa) you will need to compile your own tables.
Contrail formation is a mixing process - hot moist exhaust mixes with cold environment.

 

[Spooner]

Biggerdave I know, but online I can't find because is too old (1953) so when I started to study this I found a paper (http://www.dtic.mil/cgi-bin/GetTRDoc?AD=AD692117) very similar so I gave up, but now when I'm referencing I need to read Appleman's reference. So I'll go to uni, I'm sure that they get me this.

Mr. Marsden thanks for your thoughts, I've found tables from other references and I've done a chart in order to explain where was the real icing tunnel round this charts, my model and also the contrails real tests that I've found, now I'm working in the supersaturation phase in this chart in order to know what is happening from 100% to 120% RH.




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