Olfactory Display: Fluid Dynamic Considerations for Realistic Odor Presentation

Abstract

This paper describes some fluid dynamic considerations for attaining realistic odor presentation using an olfactory display. Molecular diffusion is an extremely slow process and, therefore, odor molecules released from their source are spread by being carried off by airflow. Since the flow we encounter is almost always turbulent, the intensities of the odors delivered from their sources to our noses fluctuate randomly over time. Experimental results are presented to show the random fluctuations of odor intensity alleviate olfactory adaptation. When the odor vapor generation from an olfactory display device is randomly modulated, the odor is felt more persistently over time than in the case of the constant release of the odor vapor. The results of computational fluid dynamics simulations are also presented to show that our body temperature affects reception of odor vapors at our noses. Convective air currents in the upward direction are generated by our body temperature. They bring the odor vapor drifting along the floor up to our noses. Without the body temperature, such odor might not be detected. The detailed fluid dynamic considerations thus enable reproduction of realistic odor stimuli that we encounter in real-life scenarios.