• Dr Val

Let's Get Nerdy!

Updated: Jan 30

We're going to talk about noses today-but first, we're going to talk about laminar flow, Poiseuille's Law, and why size really does matter.


Everyone knows that drinking through a larger straw is easier than drinking through a smaller straw, even if you're drinking a thin liquid like soda or water. But if you stop and really check the difference between the two holes, it only takes a millimeter or two to make a huge difference in the amount of liquid you can move. What gives?

Let me introduce you to the Hagen-Poiseuille Equation, aka, Poiseuille's Law. The "R" is the important piece there-that's the radius of the tube that the flow is going through. Radius is essentially half of the widest part of a circle. You'll notice that's multiplied the the 4th power. This means that any change in that radius, even a teeny-tiny one, makes a HUGE impact on fluid flow. And since that "R" is on the bottom, and the equation solves for pressure changes (ie, how easy it is to move fluid), the bigger the better. Increasing the radius of a tube something is flowing through from 3 to 4 mm, for example, will change that part of the equation from 254 to 804.

The practical applications of this idea are everywhere, but for today, the focus is on airflow. A "typical" adult nostril is 10-12 mm wide, which means an R of 5-6 mm. Nasal valve collapse, deviated septum, and other issues can decrease that by up to 70% That's the difference between a straw and a coffee stirrer, and you can imagine the impact that has on the amount of air which can be moved!

Still With Me? Great!

Enter the concept of nasal dilators. Many of these devices can effectively reopen the nostrils and nasal passages, changing that R back into the 5 to 6 mm range-BUT. The devices themselves add at least 2-3 mm of material back into the nasal cavity, which offsets a large portion of their benefit.

We Don't Get It, Either

This is why we kept SIlent so simple. Our low profile wire adds <0.5mm of material back into the nostril while opening that area with the same effect. This minimizes our impact on R while maximizing our impact on airflow-helping people #breatheeasily

#science #airflow #physics #laminarflow #nasaldilator #allergyfriendly

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