Abstract
In a preburner of liquid rocket engines, some liquid-oxygen
(LOX) posts, which introduced oxygen into combustion chamber,
experienced severe flow-induced vibration due to unsteady
cryogenic hydrogen flow. The mechanism of the vibration has not
been fully understood because of the complexity of the flow field.
In the present study, a new numerical method was developed to
analyze the flow field of hydrogen, whose characteristic properties
lie in its non-idealness and compressibility. The unsteady hydrogen
flow inside the preburner unit was analyzed to investigate the
details of hydrogen flow field as well as the mechanism of LOX
post vibration. It was clarified that hydrogen flow inside the
manifold and fluid dynamic forces on LOX posts were strongly
affected by vortices shed from the junction at the upstream of the
inlet. A baffle plate put inside the manifold was shown to reduce
unsteady fluid forces on the LOX posts.
