Simulation of the oil storage process in the scopa of specialized bees

• A 3D geometric computer model is build from an X-ray scan of a bee’s scopa.
• Postprocessing of the micro-CT data is necessary to allow for simulations.
• We perform one-phase and two-phase simulations on a microscopic length scale.
• The simulation of an oil droplet is in good agreement with X-ray measurements.
• Massively parallel computations are essential for our simulations.

Several species of specialized bees possess special structures to store and transport floral oils. By using closely spaced hairs at their back legs, the so called scopa, these bees can absorb and release oil droplets without loss. The high efficiency of this process is a matter of ongoing research. Based on recent X-ray microtomography scans from a bee’s scopa, we build a three-dimensional geometric computer model. Then, using NaSt3DGPF, a two-phase flow solver developed at the Institute for Numerical Simulation, we compute the micro flow in the scopa model. Our calculations reveal the laminar to turbulent air flow in the scopa during flight. Furthermore, we simulate the deformation of an oil droplet in the scopa due to surface tension effects on a microscopic length scale. Our results are in good agreement with measurements for an oil-wetted scopa at steady state which are obtained from X-ray scans. Both simulations are relevant for the understanding of the process of oil absorption and transportation in the real scopa of a bee. Due to the large computational complexity of the problem, massively parallel computations are essential for our simulations.