Rotational CARS thermometry and concentration measurements in ethane-nitrogen mixtures using Fourier analysis

Research output: Contribution to journalArticle


Rotational coherent anti-Stokes Raman scattering (CARS) is an established diagnostic technique for thermometry and species concentration measurements of di-atomics and tri-atomics in combustion processes; however, studies on hydrocarbon fuel molecules have been scarce. In this work, we have investigated the diagnostic potential for rotational CARS on ethane with emphasis on concentration measurements in mixtures with nitrogen. Rotational CARS spectra have periodic line structures, and because ethane and nitrogen spectra partially overlap, a novel Fourier analysis approach was developed and applied to facilitate evaluation of relative concentrations and temperatures. Instead of the standard procedure of spectral fitting using libraries of theoretically calculated spectra, the fitting was based on an experimental database of temperatures and relative ethane/nitrogen concentrations. The method was successfully demonstrated in an ethane diffusion flame where ethane, initially at room temperature, is heated downstream as well as mixed with increasing amounts of nitrogen. The evaluated temperatures and concentrations are in good agreement with computational fluid dynamic model simulations.


Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Energy Engineering


  • Concentration measurements, Ethane, Fourier analysis, Rotational CARS, Thermometry
Original languageEnglish
Pages (from-to)1096-1108
JournalJournal of Raman Spectroscopy
Issue number7
Early online date2018 Feb 14
Publication statusPublished - 2018 Jul
Publication categoryResearch