NASA NTRS2022
Corrugated metal flexhoses are used to supply fluid routing where straight rigid pipes cannot meet the design requirements due to vibrations, thermal expansion, or motion. These types of hoses are found in a wide range of applications at KSC (Exploration Ground Systems Program in particular) with various fluid commodities such as fuel, oxidizers, coolant, and cryogenics. However, flexibility of design comes at a price: due to increased levels of turbulence generated by the hose geometry, the necessary supply pressure must increase to achieve the same flow rate. Furthermore, the convolutes of the flexhoses interact with the flow field to generate areas of flow separation which leads to a phenomenon known as vortex shedding. When the frequency of vortex shedding couples with the natural frequency of the hose, this can be detrimental and cause premature failure. There are a limited amount of software that can correctly model the coupled fluid structure interactions(FSI) between the solid and fluid physics. This project aims to develop a computer model that can predict Flow-Induced Vibration (FIV) on flexhoses in one of the atypical configurations found in the State-of-the-Art (SOTA) standard for hoses in an angulated state. Our research seeks to extend the literature and expand NASA’s FIV standard. The computational rigor and resources available in the Apollo Era did not allow for flow coupling between fluids and structure interfaces to evaluate FIV of the flexhose. Our team believes that modern techniques and methods of evaluation should be used to reevaluate and extend the database of FIV and stiffness properties of flexhoses to assess the risk of failure. The core performance criteria is a computer model that is able to predict the FIV frequency within 10%.