Contributor’s Blog: Stepping inside a simulated tornado

Our new contributor leverages her background in mechanical engineering to investigate new technology that could make “Tornado Alley” safer.

My first story on “TechKnow” — yeeeaaayyy! I was so uber-excited to be reporting on tornado innovation, particularly as a computational fluid dynamist.

Spending nearly five years studying CFD for my engineering doctorate significantly changed my perception and understanding of the world around me. Here's why: Essentially, CFD uses computers to allow us to visualize the invisible. We don't normally see fluids like air and water, yet we couldn't survive without them. Computer simulations of fluid behavior can provide very pretty pictures based on temperature, pressure and velocity (or speed). Without realizing it, you've probably seen forms of CFD analysis — weather maps are generated using CFD, for example.  

Fluids can drastically affect the way machines and other pieces of engineering can perform. Massive savings in fuel have been made by incorporating “winglets” onto the tips of aircraft wings. Formula 1 cars remain safely anchored to the ground at high speeds, thanks to improving body contour design and adding spoilers. All such design decisions are most accurately made using CFD.

My particular area of interest within CFD was looking at how air flows within buildings. Failure to understand how air circulates through enclosed spaces has often contributed to “sick building” syndrome, whereby air remains stagnant and moist, which is a perfect environment for bacteria to thrive. Considering Americans spend 90 percent of their time indoors, breathing in clean fresh air is of huge importance. CFD can provide a picture of how air moves within a room.  

Because of that background, doing this story on innovative tornado technology was fascinating, as the structural improvements that we documented were based on how air flows outside of the buildings. Tornadoes are a highly complex form of fluid dynamics — so complex, in fact, that even the best scientists in this field are mind-boggled by their power to destruct.

Being from the U.K., I was fairly unfamiliar with the magnitude of destruction that tornadoes can cause here in the U.S. I was surprised to learn that the U.K. gets its share of tornadoes, too, but because buildings are constructed using very different materials, the effect is significantly different. The primary damage from tornadoes is caused by flying debris, and since it’s more likely that pigs will fly before stone and bricks do in the U.K., tornado damage in the British Isles is less obvious.

Upon arrival in Texas, the first thing that struck me was the vast open plains. No wonder tornadoes are able to form in this environment. We just don't have such wide open spaces in the U.K. as there are in America.

At the start of shooting this piece, I did not have a deep appreciation of the benefits of aboveground tornado shelters. Instinctively, belowground shelters seemed like a good enough solution. That was, until I went into one myself in Moore, Okla., close to Plaza Towers Elementary School, which was flattened by a tornado last May, tragically killing seven children.

Underground shelters can't be pleasant during a tornado; as it was, it was pretty uncomfortable even without the tornado. The first one I went into was full of dead frogs and toads that had accidentally fallen into it because the door hadn't been properly shut. The shelters were generally small and confined, and I couldn't help but panic at the thought of what could happen if flying tornado debris blocked the only way out of this claustrophobic place.  

Multifunctional aboveground shelters are definitely the way forward, and at the National Wind Institute at Texas Tech University, they are designing walls that are actually two layers of brick, with concrete and metal reinforcements laid between. Because debris produces most tornado damage, they’ve built an air cannon to test the impact resistance of materials that could be used to build safer structures.