1. Advanced Combustion Laboratory FTIR Study of Combustion Species in Several Regions of a Candle Flame ALLEN R. WHITE Department of Mechanical Engineering, Rose-Hulman Institute of Technology Terre Haute, Indiana

2. Advanced Combustion Laboratory Michael Faraday Royal Institution Christmas Lectures

3. Advanced Combustion Laboratory Orange: fuel rich (excess fuel, excess C 2 ) Blue: fuel lean (excess air, excess O 2 ) Dark region: paraffin hydrocarbons being broken down into smaller hydrocarbons Candle flames are of rich in combustion chemistry:

4. Experimental Setup Advanced Combustion Laboratory Figure 8: Megatech Mk III Visible Engine Modified with Sapphire Combustion Chamber Bruker Vertex 70 Collection area diameter ~.5mm Parabolic Mirrors

5. Advanced Combustion Laboratory Weighted, line of sight average: More interesting here…

6. Advanced Combustion Laboratory Base of candle (blue and black spectra) have higher temp due to wick CO 2

7. Upper (black) line: Candle Base Lower (yellow) line: Orange region CO C2H4C2H4 Advanced Combustion Laboratory Note that lower region shows signs of both lean combustion (CO) and rich combustion (C 2 H 4 )

8. Advanced Combustion Laboratory Spectra from flame regions:

9. Advanced Combustion Laboratory C2H4C2H4

10. C 2 H 4 Detail Advanced Combustion Laboratory As expected: increases and then decreases

11. Advanced Combustion Laboratory CO

12. Advanced Combustion Laboratory CO Detail: Upper and Base As expected: less CO in upper flame region

13. Advanced Combustion Laboratory CO Detail: Upper and Base Increasing CO in a region that should is burning rich: →Exterior CO intensity increase due to increased flame temp

14. Advanced Combustion Laboratory Thin lean region due to surrounding air

15. What if we observe dark region with an IR source? Advanced Combustion Laboratory

16. Add an IR Source: Advanced Combustion Laboratory Figure 8: Megatech Mk III Visible Engine Modified with Sapphire Combustion Chamber Bruker Vertex 70 Collection area diameter ~.5mm Parabolic Mirrors

17. Advanced Combustion Laboratory Glow plug source behind dark region: Glow plug behind candle Candle without source Hoping for C 2 H 2 or other hydrocarbons– instead: more H 2 O and CO 2

18. Conclusions Samples near base indicate higher temp due to wick C 2 H 4 presence in dark region, decreasing toward upper flame as expected CO concentration inconclusive due to: – line-of-sight averaging – Increased intensity due to higher energy IR source did not reveal additional hydrocarbons Advanced Combustion Laboratory

19. Acknowledgements Rose-Hulman Institute of Technology Dean’s Equipment Investment Fund Advanced Combustion Laboratory

20. Thank you.

21. Advanced Combustion Laboratory http://www.pysanky.info/Chemistry/Candle_Flame.html

22. C2H4 H2O CO C2H4 Advanced Combustion Laboratory