Pogo Stability Analysis
Liquid Propulsion

Pogo [poh-goh], noun, fluid-structure interaction problem common to liquid fueled launch vehicles

Pogo stability analysis is a system-level analysis that combines the dynamics of the vehicle structure with the dynamics of the vehicle propulsion system. As structure frequencies change, there is potential for propulsion system modes to interact with structural modes, thus resulting in undesirable payload/crew vibrations.

SwRI engineers have modeled the dynamics of such systems and have developed solutions for the prevention of pogo during powered flight. To date, SwRI engineers have been using a combination of commercial finite element codes and ML_Pogo for the study of vehicle stability.

image of pogo stability analysis

Pogo stability analysis is performed to study the interaction between vehicle structural and propulsion system modes as they vary over the duration of powered flight.

image of analytical tools

SwRI engineers use analytical tools, such as ML_Pogo, to study the coupled fluid-structure interaction to assess the stability of the launch vehicle system.

Related Terminology

pogo stability analysis  •  liquid propulsion experience  •  launch vehicle systems development  •  propulsion systems development  •  structural dynamics  •  fluid dynamics  •  fluid-structure interaction  •  Pogo  •  launch vehicle structural dynamics  •  propulsion system fluid dynamics  •  hydro-elastic tank modeling  •  prototype development  •  prototype testing

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Southwest Research Institute® (SwRI®), headquartered in San Antonio, Texas, is a multidisciplinary, independent, nonprofit, applied engineering and physical sciences research and development organization with 9 technical divisions.