Particle Image Velocimetry (PIV)

The sudden global outbreak of coronavirus diseases 2019 (COVID-19) has infected over seventy million people and resulted in over one million deaths by the end of 2020, posing a significant threat to human health. As potential carries of the novel coronavirus, exhaled airflow of infected individuals via coughs, are significant in virus transmission. This study measures human coughs' airflow velocity in a chamber filled with stage fog employing a particle image velocimetry (PIV) system.

Respiratory infections are transmitted by droplets and droplet nuclei generated by human coughing, sneezing, and talking. Droplets and droplet nuclei come out of the mouth simultaneously with airflow, and their dispersion characteristics are important to understand the transmission route of infection. It is crucial to understand the dispersion characteristics of droplets and droplet nuclei dispersion and infection routes through numerical analysis.

A common room-heating technique involves the use of a wall-mounted radiator without forced convection. The cold surrounding air passes adjacent to the warm surfaces of the radiator where it absorbs heat and gains momentum to rise along the wall surface and finally circulate in the entire room. Understanding the properties of heated airflows is important for several purposes. To understand the flow process it is important to identify where the transition from laminar to turbulent flow occurs and to quantify the turbulent fluctuations.

Cross-ventilation is regarded to be beneficial control method to obtain thermal comfort in a hot summer without using mechanical devices. Since it is complicated flow phenomenon, details of flow characteristics have not been sufficiently known. The final goal of this work is to establish a new prediction method of flow rate based on energy balance within the stream tube passing through or around the building. To validate numerical results obtained by CFD, they need to be compared with experimental results.

On the basis of modelling with similarity theory and by using the Archimedes number, Ar, as the similitude parameter, this paper analyzes the air distribution of a busbar corridor in a hydropower station by using the Particle Image Velocimetry (PIV) measurement technique.