关于古生物生态位和功能形态学方面的研究通常是推测性的, 而定量分析工作较少。此外由于缺少现生生物做对比等诸多因素, 使得有些假说存在争议。计算流体力学 CFD (computational fluid dynamics)在验证这些推测性假说上具有极大的潜力, 并为了解古生物的生活环境以及解释生物在进化过程中的形态变化提供了新的契机。COMSOL Multiphysics 作为一款多物理场仿真软件, 适用于对古生物的 CFD 模拟, 本文以凯里组始海百合 Globoeocrinus 模型在 COMSOL 中的流体实验为案例, 来论证关于 Globoeocrinus 螺旋的腕会使附近的水体形成湍性流动进而帮助滤食这一假说的可能性。流体模拟结果表明在水流流速 0.01–0.5 m/s 的范围内, Globoeocrinus 腕周围并没有出现湍性流动的涡, 而是形成了低流速域。低流速域的形成有利于增加始海百合滤取食物的概率。同时文章详细介绍了在 COMSOL 中进行案例研究的操作步骤, 以期望帮助更多的古生物研究者理解和应用 CFD 技术。

Functional analysis of the fossil traits is one of the significant topics in paleontology and paleoecology. However, many long-standing functional and ecological hypotheses are controversial. One of many reasons is the lackof living organisms to compare with. Computational fluid dynamics (CFD) opens a new window in paleontological research. The CFD is a method for simulating the interaction between solid surfaces and their surrounding fluid. The results of fluid properties within the flow domain can be visualized as plots and exact mechanics-related values by using a computer to numerically solve the fluid motion described by complex equations. As a multi-physical field simulation software, COMSOL multiphysics is suitable for CFD simulation of the model of fossils. In this paper, the hydrodynamic simulation of eocrinoid model from the Kaili Formation was employed as a case study to test the hypothesis that spiral brachioles would have created a turbulent zone around them. The simulation results show that there is no turbulent vortex around the brachioles but a low-velocity region within the current velocities from 0.01 m/s to 0.5 m/s. The formation of the low velocity zone enables the eocrinoid to gather food. In addition, this paper introduces detailed operation steps of hydrodynamics simulation using COMSOL, hoping to help more researchers understand and use CFD method in their studies.

国家自然科学基金(41902003)资助