corresponding author: alexander.konnov@forbrf.lth.se Laminar burning velocities of methylcyclohexane + air flames at room and elevated temperatures S.S. Matveev 1 , V.A. Alekseev 2 , I.V. Chechet 1 , S.G. Matveev 1 , A.A. Konnov 2 1. Scientific and Educational Centre of Fluid Dynamics Research, Samara National Research University, Samara, Russia 2. Division of Combustion Physics, Lund University, Lund, Sweden Introduction Aviation kerosene or jet fuel is a complex mixture of different classes of hydrocarbons with the major contributors being normal alkanes, branched chain paraffins (iso-alkanes), aromatic molecules and cyclic paraffins, cycloalkanes [1]. Formulation of the proper surrogate fuels reproducing practical (physical) and combustion characteristics of kerosene requires, therefore, detailed understanding of the combustion chemistry of each of these classes. The laminar burning velocity, one of the most important characteristics of combustible mixtures, has been recently investigated in our flame studies of n-heptane [2, 3] and n-decane [4] representing n-alkanes, of iso-octane [2, 3], of aromatic benzene [5] and toluene [2]. Cycloalkanes possess unique combustion features important for oxidation of real fuels [6, 7] and, therefore, the goal of the present study was to measure burning velocities of methylcyclohexane + air flames at room and elevated temperatures. Previously, burning velocity, S L , of methylcyclohexane was investigated in spherical and counterflow flame configurations. Kumar and Sung [8] obtained S L at atmospheric pressure and initial temperature of 400 K using the counterfow technique and linear stretch correction. Ji et al. [9] also implemented the counterflow configuration, yet the stretch-correction was performed using so-called computationally-assisted technique. The authors determined S L at atmospheric pressure and initial temperature of 353 K and found predictions of the JetSurf 1.1 model in a good agreement with their experiments. Wu et al. [10] investigated expanding spherical flames from 1 up to 20 atm and initial temperature of 353 K using non-linear stretch correction. At atmospheric pressure they found reasonable agreement with the data of Ji et al. [9], yet some discrepancies were observed in lean and rich flames. Wu et al. [10] tested JetSurf 2.0 model [11], which moderately overpredicted burning velocities of methylcyclohexane + air flames especially at atmospheric pressure. The goals of the present collaborative study were: a) to provide new experimental data over an extended range of initial temperatures including conditions visited in the previous studies [8-10]; b) to compare these data with predictions of two models: JetSurf 2.0 [11] and of the mechanism developed at Politecnico di Milano [12]. Experiments have been performed at Lund University and at Samara University using the same technique, the heat flux method, yet on experimental rigs of different design. Experimental details The determination of the laminar burning velocity was performed with the heat flux method. The initial temperature (T g ) of the methylcyclohexane + air mixtures was set to 298, 353 and 400 K, and the equivalence ratio (ϕ) was varied from 0.7 to 1.4. The purity of the fuel was above 99%, and the oxidizer was synthetic air (21% O 2 + 79% N 2 ).