Airflow visualization and air purifier positioning optimization in potentially COVID-19 contaminated classrooms. - Thomas Pfeiffer; Khadse Himanshu Dilip; Raunak Suryawanshi; Gnana Swaroop Kishnamurthy; Batcheva Domínguez Téllez; Reiner Creutzburg; Michael Hartmann (MOBMU, 2021)