Fuel-Coolant Interactions in a Shock Tube Geometry

Abstract

Shock tube experiments with a variety of liquids have been conducted in which large pressures were obtained for systems of water-Wood's metal, butanol-Wood's metal, and water-molten salt. With the water-Wood's metal system, three separate regions were observed. When the hot liquid temperature was below 210/sup 0/C (which can be identified as the spontaneous nucleation temperature), no thermal interaction occurred, and the cold liquid column only bounced if vapor were present initially (region A). When the hot liquid temperature was greater than the spontaneous nucleation temperature but the contact interface temperature was less than this value (region B), the low rate of vaporization resulted in bouncing of the liquid column, which in turn produced high pressures on the order of the theoretical water hammer pressure. Those hydrodynamic pressures are larger than the vapor pressure corresponding to the bulk temperature of the hot liquid and larger than the maximum pressure that may be generated from single-phase pressurization. The third region, observed when the hot liquid temperature was above the spontaneous nucleation temperature upon contact (region C), resulted in fast production of vapor and impulses larger than the theoretical impulse for stopping the liquid column. The mechanism for producing the high pressures inmore » region C is a combination of hydrodynamic impact and thermal interaction. Since pressures produced in region C are also on the order of impact pressures, the only indication for thermal interaction is a considerable increase in the resulting impulse of pressure pulses with short rise time (<1.0 ms).« less