Application of the Rossiter model for predicting the frequency of vortex shedding and surface oscillations in rectangular shallow reservoirs

Shallow reservoirs are ubiquitous in hydraulic engineering. Predicting the properties of the flow field in such reservoirs is instrumental to inform their design, operation, and maintenance. In previous research, oscillating jets were experimentally observed in rectangular shallow reservoirs, and we assess here the performance of a simple analytical model to predict the frequency of the dominating jet oscillation mode(s). The model couples the evaluation of the reservoir natural frequencies, with the Rossiter feedback loop formula. The analytical predictions are compared against experimental observations by reanalyzing an existing dataset. In many cases, the model predictions match the observations. Remaining discrepancies may result from experimental uncertainties, which could be reduced in future tailored laboratory tests, or from the dimensionless vortex celerity value used by the feedback loop model, which was not assessed experimentally.