Two-wavelength mid-IR diagnostic for temperature and n-dodecane concentration in an aerosol shock tube
- 177 Downloads
A two-wavelength, mid-IR optical absorption diagnostic is developed for simultaneous temperature and n-dodecane vapor concentration measurements in an aerosol-laden shock tube. FTIR absorption spectra for the temperature range 323 to 773 K are used to select the two wavelengths (3409.0 and 3432.4 nm). Shock-heated mixtures of n-dodecane vapor in argon are then used to extend absorption cross section data at these wavelengths to 1322 K. The sensor is used to validate a model of the post-evaporation temperature and pressure of shock-heated fuel aerosol, which can ultimately be used for the study of the chemistry of low-vapor-pressure compounds and fuel blends. The signal-to-noise ratio of the temperature and concentration are ∼20 and ∼30, respectively, illustrating the sensitivity of this diagnostic. The good agreement between model and measurement provide confidence in the use of this aerosol shock tube to provide well-known thermodynamic conditions. At high temperatures, pseudo-first-order decomposition rates are extracted from time-resolved concentration measurements, and data from vapor and aerosol shocks are found to be in good agreement. Notably, the n-dodecane concentration measurements exhibit slower decomposition than predicted by models using two published reaction mechanisms, illustrating the need for further kinetic studies of this hydrocarbon. These results demonstrate the potential of multi-wavelength mid-IR laser sensors for hydrocarbon measurements in environments with time-varying temperature and concentration.
PACS42.62.Fi 82.30.Lp 07.07.Df
Unable to display preview. Download preview PDF.
- 2.A.C. Eckbreth, Laser Diagnostics for Combustion Temperature and Species (Abacus Press, Cambridge, 1988) Google Scholar
- 3.J.B. Jeffries, K. Kohse-Hoinghaus, Applied Combustion Diagnostics (Taylor & Francis, New York, 2002) Google Scholar
- 6.A. Kakuho, K. Yamaguchi, Y. Hashizume, T. Urushihara, T. Itoh, E. Tomita, in 2004 SAE Fuels & Lubricants Meeting & Exhibition (Toulouse, France) 2004-01-1946 (2004) Google Scholar
- 13.M.J. Hall, M. Koenig, Proc. Combust. Inst. 26, 2613 (1996) Google Scholar
- 15.A.E. Klingbeil, J.B. Jeffries, R.K. Hanson, Two-wavelength mid-IR absorption diagnostic for simultaneous measurement of temperature and hydrocarbon fuel concentration. Proc. Combust. Inst. 32 (2009, in press) Google Scholar
- 16.J. Kashdan, T.C. Hanson, E. Piper, D.F. Davidson, R.K. Hanson, in 42nd Aerospace Meeting (Reno, NV), AIAA-2004-0468 (2004) Google Scholar
- 18.D.F. Davidson, D.R. Haylett, R.K. Hanson, Development of an aerosol shock tube for kinetic studies of low-vapo-pressure fuels. Combust. Flame (2008, in press) Google Scholar
- 21.E.A. Barbour, R.K. Hanson, P. Hutcheson, C.M. Brophy, J.O. Sinibaldi, in 45th AIAA Aerospace Sciences Meeting and Exhibit (Reno, NV), AIAA-2007-232 (2007) Google Scholar
- 22.J.J. Scherer, Laser Focus World 43, 103–106 (2007) Google Scholar
- 28.H.R. Zhang, Ph.D. Dissertation, Department of Chemical Engineering, University of Utah, Salt Lake City, UT, May, 2005 Google Scholar