Bowing of Cryogenic Pipelines

Abstract

The design of propellant loading systems for present-day missiles involves the design of pipelines that can carry cryogenic fluids and requires an additional consideration beyond the conventional analyses for flexibility and dead weight. Because of varying flow conditions and boil-off, these cryogenic lines experience varying fill levels and concomitant temperature gradients which cause these lines to bow; i.e., to assume a uniform curvature of circular arc. If constrained, the thermal-stress distributions which are generated by the temperature gradients will have superposed on them additional stresses, which result from the action of the support constraints. This combination of stresses may be critical and/or the loads on the supports may be excessive. The following analysis investigates these bowing effects, thermal stresses, and indicates the support problems entailed.