Tegart, J. | Engineering Papers

NASA NTRS1982

Collapse of large vapor bubbles

The refilling of propellant tanks while in a low-gravity environment requires that entrapped vapor bubbles be collapsed by increasing the system pressure. Tests were performed to verify the mechanism of collapse for these large vapor bubbles with the thermodynamic conditions, geometry, and boundary conditions being those applicable to propellant storage systems. For these conditions it was found that conduction heat transfer determined the collapse rate, with the specific bubble geometry having a significant influence.

Tegart, J.↗

NASA NTRS1975

Propellant reorientation with off-axis accelerations

Reorientation of propellant within a tank is important to the design of many acquisition and vent systems. A drop tower test program was conducted to determine the influence of off-axis accelerations on the motion of the liquid. A series of 39 tests was performed with a spherical tank and a cylindrical tank with hemispherical end domes, varying tank orientation, liquid volume and the magnitude of the acceleration. It was shown that reorientation under the effect of a pure axial acceleration, which has been studied in prior test programs, is a special case. The lateral component of the acceleration caused the liquid to reorient along one side of the tank. The motion of the liquid appeared to be independent of the magnitude of the lateral acceleration for the range of values considered.

Tegart, J.↗