クアッドロータドローンによる漏洩水素センシングの機構解明

抄録

Hydrogen leakage is anticipated in various occasions ranging from production to consumption. In order to realize a hydrogen sensing system more flexible and quicker than current systems, we developed a new system with a small thermal conductivity-type hydrogen sensor on a drone. Initially, it was thought that a quadrotor drone was not suitable for hydrogen leak detection because propeller airflow prevents gas arrival to the sensor placed on the drone. In this study, we demonstrate that hydrogen is certainly detected in spite of the propeller airflow and propose a new mechanism of continuous hydrogen sensing by a quadrotor drone. For that purpose, we conduct hydrogen leak experiments, smoke visualization of flows around the drone and computational fluid dynamics (CFD) analysis and clarify the path through which hydrogen from the leak source reaches the drone. Flow circulation is formed around the drone accompanying the suction and discharge of air from the propellers. Hydrogen from the leak source rides on this circulating flow and arrives at the drone, rather than rising up directly to the drone. Because this circulating airflow is inevitably formed associated with the propeller rotation of the drone, and it stably and strongly transports hydrogen from the leak source to the drone.