Estimation of exergetic behaviour of the human respiratory tract

The present work analyses the exergetic behaviour of the human respiratory system, including chemical exergy transfer during alveolar gas diffusion. The trends of entropy generation and exergy destruction in the respiratory tract due to airflow for different physical activity levels have been assessed. Furthermore, the effect of inhaled air temperature on tracheal exergy destruction has been assessed. The study for the first time extends the concept of exergetic efficiency for human respiratory tract, which accounts for energy losses in the branches of the trachea. The findings indicate that human lung efficiency decreases as physical activity levels rise.