Integrated analysis of flow and diffusion for efficient particle capture by an array of sensilla

The antenna of a male insect can capture pheromones generated by a female insect. In this study, the sensilla of an antenna are represented by a row of cylinders, and the mass of pheromones they capture along with the capture rate are calculated. The diameter of the real sensilla of a moth Bombyx mori is assumed in the calculation. Reynolds number and Péclet number, which are defined by the diameter of cylinders and the uniform flow, are 0.04 and 0.26, respectively. Calculation parameters are the gap between neighboring cylinders representing sensilla and their angle of attack. For a high angle of attack, the analytical exams show that the capture rate is maximized when the ratio of the gap between cylinders to their diameter is 10. In all the cases, the capture rate is maximum when the angle of attack is 90 degrees and the ratio of the gap between cylinders to their diameter is 10. This ratio is close to that observed in the sensilla of a moth Bombyx mori. When the ratio of the gap between cylinders to their diameter is smaller than 3, the capture rate is nearly independent of the ratio of the gap between cylinders to their diameter and the angle of attack.