Exhaust Plume Radiation Model
Exhaust Plume Radiation Model
(OP)
Hi,
I am doing some research for a company and I am looking into a thermal radiation model for exhaust plumes on gas turbines (model to be implemented for off-shore and onshore oil platforms and more of an engineering model rather than CFD e.t.c). I am looking for a calculation method which takes account of variables such as temperature, exhaust flow, wind and nozzle type. Hopefully then yielding plume deflection and thermal radiation. I would be grateful if someone could point me in the right direction for finding research papers on this topic or even point me to some good papers. I am currently attempting to sift through Google scholar, a lot of it seems to be on rocket exhaust plumes and I am unsure of the relevance of that. Thank you.
I am doing some research for a company and I am looking into a thermal radiation model for exhaust plumes on gas turbines (model to be implemented for off-shore and onshore oil platforms and more of an engineering model rather than CFD e.t.c). I am looking for a calculation method which takes account of variables such as temperature, exhaust flow, wind and nozzle type. Hopefully then yielding plume deflection and thermal radiation. I would be grateful if someone could point me in the right direction for finding research papers on this topic or even point me to some good papers. I am currently attempting to sift through Google scholar, a lot of it seems to be on rocket exhaust plumes and I am unsure of the relevance of that. Thank you.





RE: Exhaust Plume Radiation Model
- Many do not perform cross wind or jetting the flow into the wind.
- Obstacles are not handled easily.
I hope I've been of some help.
--Mike--
RE: Exhaust Plume Radiation Model
Thanks
RE: Exhaust Plume Radiation Model
As a good source of knowledge, take a look to "Fundamentals of Stack Gas Dispersión", 4th Edition, Milton R. Beychok, Irvine, California, 1994.
El que no puede andar, se sienta.
RE: Exhaust Plume Radiation Model
RE: Exhaust Plume Radiation Model
The exhaust of a one-through GT will be 1200-1400 degrees F, and will be moving at several hundreds of ft/sec. Assume 10-15 feet in diameter for big GT, maybe 4-8 feet for a small one. That 1200 deg F air mass will only cool after it leaves the stack area and begins mixing with the surrounding air.
So your thermal radiation source needs to at least start with a 4-8 foot diameter hot gas cylinder extending vertically 100-150 feet up before it begins mixing with the cooler surrounding air ... then cooling and expanding into a large cone that ends up at only 200-300 degrees after maybe 400 feet. once you get that assumption made, go look at a few flumes with an IR camera, make your first measurements in still air, and start thinking about wind directions.
RE: Exhaust Plume Radiation Model
RE: Exhaust Plume Radiation Model
"Nobody expects the Spanish Inquisition! "
RE: Exhaust Plume Radiation Model
Can you please clarify this statement,
"Gases can only emit radiation at frequencies where they absorb."
I'm having trouble grasping what you meant there.
Cheers
RE: Exhaust Plume Radiation Model
If you do want to bother, first the power law, if you still want to bother, I wouldn't do much research, in excel or matlab just do 1D simulation with emmisivity, absorbitivity, (reflectivity irrelevant obviously) molecular size and a simple for loop or a few hundred...thousand cells, and look at the radiation from the outside, to T(ambient) to 1 ft out to 2 ft out to 3 ft out. While the initial effects of radiation may be a bit chaotic with greybody radiation and resonant frequencies, follow the power law modified a bit for a longer area.
RE: Exhaust Plume Radiation Model
If you want to learn more about radiation heat transfer from gases you can also try Fundamentals of Heat and Mass Transfer 6th edition by Icropera, DeWitt, Bergman, and Lavine. Chapter 13 discuses radiation heat transfer and Section 13.4 goes into some detailed equations regarding radiation from gases.
RE: Exhaust Plume Radiation Model
"Nobody expects the Spanish Inquisition! "