Numerical Assessment of an Air Cleaner Device under Different Working Conditions in an Indoor Environment

Transmission and spread of exhaled contaminants in the air may cause many airborne infectious diseases. In addition to appropriate ventilation, air cleaner devices are used as one of the most common ways to improve the indoor air quality. Therefore, it is necessary to understand the performance of an air cleaner under different operating conditions. This study mainly concerns investigating the effect of presence or absence of furniture and its displacement on the removal rate of the particles leaving a person’s mouth while coughing in an isolated room. Moreover, the effect of air exit angle of the device on removal rate of contaminated particles and the pattern of their dispersion within a room was studied. To this aim, computational fluid dynamics were employed to examine the mentioned effects by using the Eulerian− Lagrangian method. As the results indicated, when the furniture was placed farther away from the device, more particles were removed by the device. Additionally, the air ejection angle of the air cleaner device significantly affects the removal of particles. Results of the present study could improve use of air cleaner devices for maximum reduction of particles in the indoor environment.

Dynamics of diffusion jet combustion in an ejection burner

In this work we present the results of computational and experimental studies on the burnout dynamics of diffusion gas jets in an ejection burner with a two-stage air ejection scheme. It is shown that usage of this scheme leads to an increase in the uniformity of the distribution of thermogasdynamic parameters at the burner outlet, an increase in the completeness of combustion of the fuel, and a more stable operation of the device.