RESPIRATORY DROPLET DYNAMICS ANALYSIS OF DENTAL CLINIC IN HOSPITAL USING CFD

• Main Author: Riezaldy Ahmad, Afief
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/79263
• Institution: Institut Teknologi Bandung

COVID-19 disease caused by SARS-CoV-2 virus is transmitted in air mainly by respiratory droplets as a result of breathing, sneezing, or cough. Droplets handling using ventilation system is necessary in high risk environment such as dental clinics, but current related standards are limited; therefore, the study of virus transmission in dental clinic’s ventilation system is still needed. This study evaluates the droplet transmission risk in dental clinic at Hasan Sadikin Hospital Bandung using three-dimensional computational fluid dynamics (CFD) model for one cough case originated from dental patient. Air flow, droplet trajectories and droplet evaporation equations were modelled as an input in ANSYS Fluent software, along with suitable boundary conditions. The droplet trajectories, dispersion and evaporation were then analyzed to obtain the virus transmission risk. To further reduce the risk, system modifications and simulations were subsequently conducted by means of increasing the ventilation rate, changing the airflow inlet into diffuser, adding extra exhaust duct, increasing relative humidity, and inactivating the air conditioner. Respiratory droplets were completely removed from the air in 8 min, which is lower than recommended disinfection time for dental clinics of 15 min. Droplets count left in the air after 2.16 min was 73 droplets, below the maximum number allowed of 100 droplets. Modification simulation showed tha adding extra exhaust duct would effectively shorten the droplets removal time to 0.75 min and lowered their numbers by 83.5% to 12 droplets.