ABSTRACT

Studies of a new transient thermohydraulic modeling of a capillary pumped loop for terrestrial application (CPLTA) are proposed in this two-part paper. In part A, the concept of this modeling is first of all briefly described. Using finite volumes method, this 1D-model is based on Navier-Stokes equations for transcribing fluid mechanical aspects. The main feature of this model is based on a network representation by analogy with electrical. The validation of this model is done on a specific CPL designed for integrated power electronics cooling in ground transportation, with ethanol as working fluid and fast transient applications of heat power applied at the evaporator. Then, a precise and quantitative numerical study on the body and surface forces in momentum balance equations, along the loop, allows a better understanding of the effects of the gravity field on the behavior of this CPL, especially during strong transient phases as faced in terrestrial application. Indeed, the gravity forces are predominant on the liquid phase, which induces a specific hydraulic coupling between the condenser and the liquid line. Furthermore in the two-phase area in condenser, the competition between viscous and advection forces is shown.