Numerical and experimental predictions of heterogeneous condensate flow of moist air in cooled pipe

Condensate flows of moist air in a cooled pipe are numerically investigated by using the preconditioning method for solving incompressible and compressible Navier–Stokes equations with additional equations and source terms for condensate flows. The corresponding experiments are also conducted with the calculated results being compared with the experimental results. The present numerical method can apply not only to compresssible flows, but also to flows at a very low Mach number with condensation without the stiffness of solution. Very slow flows of moist air in a cooled pipe (in which the wall is partially cooled) are calculated using this method by assuming heterogeneous condensation. Then, humidity loss due to condensation when stream of moist air flow in the cooled pipe is numerically and experimentally predicted.