Preliminary Stability Maps Created Using Cathena for Heated Channels With Supercritical Fluids

Abstract

Although supercritical water does not undergo a phase change, there are large property variations near the pseudo-critical point which can introduce instabilities at low mass flows or high power levels. Stability maps have been created using CATHENA MOD 3-5d/Rev3 which identify the power to mass flow ratio at which a flow instability is expected to occur for a given inlet enthalpy, inlet throttling, and outlet throttling. The maps exhibit a similar characteristic shape to boiling water stability maps as well as to supercritical water maps created using other modeling tools. They indicate that, as in boiling water flow, there are two regions of instability: an excursive instability region and an oscillatory instability region.