Shear Thickening as Passive Damping: Enhancing Aeroelastic Behavior of Cantilevered Probes in Transversable Turbomachinery Instrumentation

Abstract The present study consists of a low fidelity specialized modeling of the flow – probe interaction and presents an attempt to mitigate its deformation. The aim is to further illuminate the impact of fluid-structure interaction on typical traversable instrumentation by predicting their angle of deformation and dynamic response, and subsequently propose and result in mitigating measures. Incorporating a non-Newtonian fluid in the apparatus emerges as a distinguished perspective as it introduces a self-adjusting mechanism owed to the fluid’s varying viscosity. The shear thickening behavior and attributes are extracted analytically and modelled as a corrective/damping force acting on the cantilevered probe. Despite the occurrence of quasi-steady thermodynamic phenomena, common measuring non-optic instruments are not exempt from the highly aeroelastic and highly unsteady environment of turbomachines. FSI phenomena induce measurement accuracy tradeoffs and demand preventive/preemptive studies for the protection of all equipment. Assessing the dynamic nature of measurement contributes to maintaining high measurement reliability while also safeguarding against any consequential damage to the equipment. Key objectives of the present study include formulating a case-study/base model using low-fidelity modelling within a programming environment to examine the one-way fluid-structure interaction static deformation and dynamic response of the cantilevered pitot beam. The flow data are derived from previous experimental studies, while the solid component, the probe, is represented by an array of one-dimensional beam elements throughout the modelling process. Regarding the shear-thickening behaviour of the base model, a literature review identified the appropriate suspension/fluid. The properties of this fluid are incorporated into and managed by the analytical model to derive the induced damping force. Despite the expected negligible deformation resulting from the case study, the precision of low fidelity modelling in predicting the aeroelastic behaviour underscores the potential of such simple, heuristic but well-founded simulations to offer reliable, customizable, and expansive insights. The literature on non-Newtonian fluids, although somewhat scattered in addressing specific needs, can be distilled to key points. In this context, we can efficiently streamline their study as passive damping mechanisms, thereby establishing the design procedure and methodology for shear thickening fluid (STF) selection.