The study is done in a network together with several different universities, where Luleå University of Technology (LTU) is one of them. According to Staffan Lundström, professor of fluid theory, it was the corona virus that in a way caused the network to be initiated.

- These groupings have worked together with how particles flow in other areas, such as the paper industry and inhalers. So the network has existed in a way, but now it's a little focused on what the different universities are doing in this area.

Uses mirrors and flashlight

The research is done, among other things, through simulations, ie virtual models in computers, of how people, for example, cough. There are various methods to see how air and particles are dispersed.

By means of the so-called schlieren method, researchers can, among other things, use mirrors, a flashlight and camera to visualize changes in the refractive index of gases, such as air.

Increase the understanding

- The air that is heated in the lungs is warmer than the surroundings, and this method is sensitive to see differences and changes in air temperature. When we cough we get a flow and in the flow from the mouth there are small liquid particles and there are viruses and everything that spreads. This is exactly what we can see, says Per Gren, associate professor of experimental mechanics.

Through the tests, the researchers hope to be able to increase the understanding of how oral protection works if they do not sit exactly as intended, but to see how particles move is important in several areas, the researchers believe, even though it has become highly current in connection with the corona pandemic.

- Now it is quite obvious that if you have particles that carry viruses you want to know where they end up, that is almost everyone is interested in, says Staffan Lundström.