Harriet B. Drage , Stephen Pates, Nicholas J. Minter

Computational Fluid Dynamics (CFD) simulations are increasingly used to test palaeoecological hypotheses. These analyses output simulated velocity and pressure flow profiles, and drag and lift force values acting on a model. These outputs are presumed to be internally consistent, assuming consistently applied parameters, but it is unclear whether these reflect real-world force measurements. Without having certainty in the simulated force outputs, we risk the resulting palaeoecological hypotheses lacking robustness. To test the difference between simulated and real-world force values, Experimental Fluid Dynamics (EFD) analyses using flume tanks can be performed, though these have rarely been done for palaeobiological research. We present ongoing, preliminary work to produce a broadly applicable protocol for performing EFD analyses to validate CFD results. We discuss digital model production and the considerations involved in 3D printing models to use in EFD, present the low-cost, open-source circuitry equipment used to measure forces, and display the jig built to support the circuitry above the flume tank during experiments. This protocol is undergoing refinement prior to data collection, including the method to attach the load cells to the jig and the material used for the beam connecting the model to the jig. Following refinement, this protocol will be consequently updated, and a series of validation values will be produced for major early Palaeozoic arthropod body plans under different flow regimes in varied water column positions. These values can be used to validate CFD results of varied future studies, and the protocol replicated to support others in performing EFD validation of palaeoecological hypothesis-testing experiments.