WEEP HOLE AND INTERLAYER GAP FLOW WITHIN LAYERED PRESSURE VESSELS

摘要

Weep hole flow rates due to interlayer gap flow generated by an external pressure source are measured experimentally for an AO Smith Layered Pressure Vessel (LPV) at the NASA Marshall Space Flight Center. A Computational Fluid Dynamics (CFD) model of the flow through the interlayer gaps is also done to provide further insight regarding flow behavior. The objectives of this project were: (i), to devise and conduct a suitable experiment that accurately measures weep hole flow rates based on pressure input at a single weep hole, and (ii), to interpret the data and provide recommendations regarding the management of potential leaks or failures of these LPVs. CFD predictions and experimental results both indicated that weep hole flow rates increase with increasing numbers of available layer gaps and increasing pressure. The highest flow rates occurred between weep holes that were longitudinally aligned, with the shortest path between them having no curvature. Flow rate results were not symmetric for weep holes located on opposite sides of any curved path. Results indicate that the proximity of weep holes to longitudinal welds appears to have a significant influence on flow symmetry, and that weep hole flow measurement may be a good indicator of localized gapping and inconsistent layer concentricity.