ONTO QUANTIFYING UNSTEADY PROPULSION CHARECTERISTICS USING MOMENTUM AND ENERGY CONTROL VOLUME ASSESMENTS

This work proposes a novel approach to characterize unsteady, undulating propulsion components through evaluating the momentum and energy equations using detailed control volume analyses. Specifically, it is difficult in such conditions to separate thrust from drag as pressure components are inseparable. In general, the goal is to link physical processes to various components in the control volume assessments that are measurable in detailed computational fluid dynamics (CFD) models. The effort utilizes the Method of Manufactured Solutions (MMS) to verify detailed insight can be extracted from the control volume assessments are developed and indicate that the energy equation uniquely highlights lift-work in the energy budget and separating propulsive and drag forces. The effort expands the findings to previously validated CFD studies studying thrust from heaving and pitching foils; results indicate a novel approach to separate the axial force into thrust and drag components. Overall, the results indicate a promising method useful to separate losses from propulsive mechanisms along with novel metrics of efficiencies useful to measuring self-propelling vehicles.