Fundamental Investigation on the Tribological Failure Mechanisms of Compressor Surfaces-Scuffing

P. S. Hrnjak, S. P. Vanka A combined experimental and computational study will be undertaken to develop better understanding and control of dispersed two-phase flow in headers. First, we will examine misty flow regimes in headers using the refrigeration setup from Project 96 for which the liquid and vapor phase flow rates can be individually measured from five tubes distributed along the length of a header. A model of two-phase flow in headers will be developed which will be directly compared to experiments. Second, a more fundamental understanding of dispersed two-phase flow over a backward step, which simulates the sudden expansion at the inlet of a typical header, will be conducted using LDV/PDPA. The particle size, particle volume fraction and Reynolds number will all be varied over ranges applicable to headers and their effects noted. A Large Eddy Simulation (LES) code will be developed which will predict dispersed two-phase flow and corresponding comparisons with the experiments will be made.