Challenges in designing a POGO suppression device for cryo environment

The pogo phenomenon occurs, when the interaction between the longitudinal modes of vibration of the vehicle structure and the liquid propulsion system exhibits instability. To avoid this harmful effect, a pogo suppression device is required, which helps to decouple these two modes. Generally, an accumulator type of pogo corrector is used in launch vehicles. But for cryogenic feedlines, providing pressurization with a gas is difficult, and has inherent disadvantages connected with specific orientation requirements. This paper illustrates the challenges in designing a pogo corrector for cryo environment. The iterative procedure of finding the optimized design considering minimum size and weight of the system is discussed in detail. Another option with a spring material suitable for cryogenic environment and with better properties than stainless steel has also been looked into. For higher pressure applications further modifications are also considered such as nesting of springs.