Mass flow rate measurement of thermal creep flow from transitional to slip flow regime

International audienceThe measurements of the thermal creep flow through a single rectangular micro channel connected to two tanks maintained initially at the same pressure, but at different temperatures , is carried out for five noble gas species, in a large pressure variation range and for two temperature differences between the tanks. The time dependent pressure variations in both cold and hot tanks are investigated, and the temperature driven (thermal creep) mass flow rate between two tanks is calculated from these data for the rarefaction parameter ranging from the transitional to slip flow regime. The measured mass flow rate is compared with the numerical solution of the S-model kinetic equation, showing good agreement with each other. A novel approximative expression to calculate the temperature driven mass flow rate in the transitional and slip flow regimes is proposed. This expression provides the results in good agreement with the measured values of the mass flow rate. In the slip flow regime, the thermal slip coefficient is calculated by employing the previously reported methodology, and the influence of the gas nature on this coefficient is investigated. The measured values of the thermal slip coefficient agree well with the values available in the literature, indicating that this coefficient is independent of the shape of a channel