Influence of Latent Heat in the Nasal Cavity

Abstract

Among the several functions of the nasal cavity, temperature and humidity adjustments are important for preserving the trachea and lungs. The functions of the nasal cavity have been clarified in experiments investigating the conditions in the nasal cavity. However, the difficulties of noninvasive measurements have rendered nasal cavity simulations an attractive alternative. Data are readily obtained from a simulated result. In this study, airflow, temperature, and humidity transfer in the human nasal cavity were investigated in a nasal cavity wall model of temperature and humidity transport. The simulated result was verified by comparison with experimental data. A reasonable agreement was attained between experimental data and a model incorporating the latent heat effect. The model simulates heat and water exchange in the nasal cavity. In all cases, the temperature and humidity of the inhaled air were adjusted to suitable physiological values. Temperature and humidity gradients were highest at the front of the nasal cavity. The influence of latent heat was clarified by comparing simulation results with and without latent heat under several inhaled air conditions. In the hot-humid inhaled air case, temperature in the Kiesselbach area was increased by latent heat of condensation, and relative humidity declined. In the other inhaled air cases, the temperature in the Kiesselbach area was decreased by latent heat of evaporation, while relative humidity increased. Latent heat effect was particularly influential in the hot inhaled air case.

Keywords

• latent heat effect
• heat exchange
• water exchange
• airflow
• nasal cavity simulation