Heat transfer and thermodynamic analysis of internal flow based on distributed parameter model

The distributed parameter model (DPM) of internal flow was presented for the cases, where large temperature variation or phase change existed. In this model the boundary conditions, thermo-physical properties, heat transfer and friction correlations all used the local values. By replacing the temperature equation with enthalpy equation in DPM, the governing equation could be unified for both single phase and phase change conditions. Hence, the more precise results of heat transfer and thermodynamics for internal flow could be obtained easily. The result of DPM agreed well with the analytic solution of fully developed laminar internal flow of air. On the basis of DPM, the characteristics of temperature and entropy generation were calculated for glycerol with great change of thermo-physical properties and humid air with phase change. This study is very important not only for the basic research of internal flow but also for the 3D DPM of the heat exchanger.