Fig. 2 CFD results. CFD results. Results of CFD simulations in horizontal (left column) and vertical (right column) cross-sections. All models oriented parallel to flow, at moderate burial depth, and simulations were performed using an inlet velocity of 0.2 m/s. (Top) Single-model simulation results. (Middle) Spaced multiple-model simulation results. (Bottom) Clumped multiple-model simulation results. Brandt M. Gibson et al. Sci Adv 2019;5:eaaw0260 Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).