Coefficients for the calculation of thermophysical properties of indolene/ethanol biofuels for transcritical engine simulations

Abstract

Driven by fuel economy and emission control concerns, modern automotive internal combustion engines operate at increasingly higher pressures and temperatures. The development of new low emission advanced combustion concepts rely on accurate predictions of the fuel mixture formation and combustion, sometimes near or across the critical point of the fuel blend. The present work provides libraries of thermodynamic and transport properties of automotive certification fuel surrogate, indolene, and its mixtures with ethanol E5, E10, E15, E20, E25, E50 and E85, to be used in the subcritical and supercritical range, in order to make transcritical fuel predictions possible and accurate.Values of enthalpy, latent heat of vaporisation, isobaric and isochoric specific heat capacity, entropy, surface tension, thermal conductivity, density, vapour pressure and viscosity are obtained numerically through theoretical and semi-empirical correlations and given for all the specified mixtures in the form of polynomial functions of temperature. The synthesis of the coefficients was obtained by minimising the least-squares-errors through a 5th order polynomial regression fit method. This format is particularly convenient for implementing computer equations or for use in CFD numerical codes.