MASS-TRANSFER AND MOMENTUM-TRANSFER IN HYDROGEN AIR AND METHANE/AIR MIXTURES/

In this article we present results for the viscosity and the mass tran sfer rates of hydrogen/air, hydrogen/oxygen, methane/air and methane/o xygen mixtures in the temperature range from 1000 to 7000 K and a pres sure range from 10(3) to 10(6) Pa. In addition, the combustion ratio i s varied from 0 to infinity. The transport properties are calculated f rom the first order solution of the Chapman Enskog approach to the Bol tzmann equation, assuming chemical equilibrium composition. An extensi ve literature study was performed to derive experimental and/or theore tically based data for the respective binary interaction potentials. T he values of the collision integrals, as derived from a complex numeri cal integration procedure, are correlated to an approximation formula. In addition, the exact solutions of the kinetic theory are compared t o frequently used empirical mixture rules. For the mixture viscosity a n easy approximation formula is deduced from the gas-kinetic theory.