Computer-Assisted Experiments for the Identification of the Two-Phase Viscosity of Fluids

摘要

The description of several transport phenomena requires the information about the viscosity of fluids.One application is a capillary tube that is operated as throttle device in the context of a heat pump.The two-phase pressure drop in the capillary tube can commonly be described using the homogenous flow model, which requires a valid correlation of the two-phase viscosity.Yet, no reliable correlation is available in literature, such that it is predictive for an extensive operation area.A lack of consistent and detailed experimental data as well as the lack of precise capillary specification complicates the matching of experimental and numerical results of the two-phase viscosity.For this reason, this work presents a systematic and comprehensive procedure in order to be able to identify a reliable two-phase viscosity.The procedure is a symbiosis of systematical numerical and experimental analysis of a two-phase refrigerant flow through a capillary tube.The numerical pre-analysis serves to identify sensitive parameters, which are experimentally refined afterwards.Comprehensive experimental investigations of the two-phase flow through the capillary provide understanding of different flow phenomena, which are inadequately described up to now.Numerical preanalysis and extensive experimental investigations are the precondition for a computer-aided identification of the two-phase viscosity based on the experimental database.