For me, science and engineering has always been about designing solutions to the various problems in our everyday lives. When I began doing research in seventh grade, my very first project was a roof that converted the impact energy of precipitation into electricity to help power the home. The following year, I came up with a dynamically supportive knee brace that implements smart fluids to vary the amount of support that patients received, depending on the physical activity. Last year, I created a self-cleaning outdoor garbage bin to tackle the issue of urban sanitation in our neighborhoods.
Yet perhaps, I am best known for my most recent project, which won the 2015 Intel International Science and Engineering Fair, out of 1,700 students nationally selected from 75+ countries. This year, I tackled the issue of airborne pathogen spread in aircraft cabins, generating the industry’s first high fidelity simulations of airflow inside airplane cabins. Using my insights, I engineered economically feasible solutions that altered cabin airflow patterns, creating personalized breathing zones for each individual passenger to effectively curb pathogen inhalation by up to 55 times and improve fresh air inhalation by more than 190%.
Billions of people travel in airplanes annually, where isolated air in densely packed aircraft cabins can propagate disease via both direct airborne and large droplet routes. When I learned about the Ebola outbreak last year, I was astonished at just how vulnerable the airplane cabin environment could be in propagating disease epidemics. What’s worse, while Ebola spreads mainly through range-limited, large droplet routes, other diseases, including SARS and Influenza, can propagate very far through the air in their aerosol forms. In fact, when we look at some statistics behind these disease outbreaks, the numbers are staggering: One group of researchers discovered that a passenger with H1N1 could spread disease to up to 17 other passengers per flight. Another group published a case study in which one SARS afflicted passenger had infected 22 others in a matter of three hours on a single flight.
Millions of dollars have been invested into studying the exteriors of aircraft, aiming to improve factors like aerodynamics and fuel efficiency. Sadly, when we examine current research in the field of aircraft cabin airflow, we find that our understanding is largely incomplete. Because of the limited resolution of empirical measurement methods, CFD analyses have come to be the preferred tools in industry. However, much of the existing work with aircraft cabin airflow, both commercially and in academia, is affected by critical errors: we find papers that have over-approximated the geometries of humans and cabin surfaces, models that have misplaced key cabin air inlets, and research that has failed to consider complex interactions between multiple physics. All of these factors add up to obscure the industry’s understanding of actual cabin airflow scenarios.
Thus, in my research, I made it one of my top priorities to understand what was really going on inside the aircraft cabin. Referencing publically available technical drawings and statistical data, I built my CAD geometry from scratch, ensuring the precise modelling of human mannequins and key cabin surfaces. I also wanted to ensure that all appropriate physical phenomena, including thermal and buoyancy effects, were properly accounted for. When it came time to select my simulation software, there was absolutely no question: an overwhelming amount of papers in industry pointed to ANSYS as the simulation code of choice. So, I made a cold call, explained my vision, and hoped for the best: here I was, an ambitious high school junior, wanting to change the way that airflow is handled in commercial aircraft cabins. You can imagine just how appreciative I was when ANSYS agreed to sponsor a CFD software package license for my project.
For me, stepping into the CFD world required a dramatic shift in my technical skillset. Through my work with robotics and previous science fair projects, I had built up about 3 years of experience with CAD modeling. I had also picked up programming, and calculus-based physics as interests in my spare time. Clearly, CFD work requires a significant depth of understanding in all of these areas. So, I embarked on a quest to learn the ropes of CFD, paging through papers, and going through Open Courseware. It also wasn’t before long that I realized the constraints that computational power had placed on previous research; this fact prompted me to build a computer with a special eight-core processor to tackle the anticipated complexities of my simulation.
Every day after school, I’d spend at least three hours chugging away at my project. As I built up my confidence, I transitioned into modelling my own flow scenarios, beginning simulations with just an empty cabin shell, and gradually progressing in complexity. Previous research largely relied on relatively low resolution, 3-5 million cell meshes that didn’t give us a full understanding of the flow field. With my simulations, I implemented the industry’s first 20-million cell mesh, together with precise geometric surfaces and carefully selected mathematical physics models to obtain the most representative results possible.
Through these simulations, what becomes evident is that the key issue with disease transmission occurs when a passenger sneezes inside the cabin. In a traditional cabin, airflow patterns can continuously throw around the pathogen contaminants without providing them an opportunity to be absorbed by the HEPA filters in the air outlets near the bottom of the cabin.
As this simulation demonstrates, pathogens from passenger effluents can continuously swirl around the cabin, passing by the neighbors’ breathing zones several times before ever reaching the outlets for filtration. And, while passengers are able to actively take measures, such as by washing their hands, to avoid infection from contaminants on table trays and other cabin surfaces, the effects of the global airflow situation in the cabin is significantly more difficult to counteract.
Thus, I decided to take my work a step further, using the insights that I gained through 32 simulations of various airflow scenarios, to multi-iteratively engineer an optimized solution to improve cabin airflow. This ultimately led to my patent pending cabin air inlet director system, which, manufactured for the price of a typical passenger’s airline ticket and installed overnight at the gate, increases passenger fresh air availability by over 190% and reduces pathogen inhalation concentrations by up to 55 times versus conventional, unmodified cabins. These novel airflow systems were then physically tested with scale models and placed through various feasibility studies, all of which concurred with the CFD findings in supporting the efficacy of my innovations.
In the coming summer months, and throughout my senior year in high school next year, I hope to work with airlines and aircraft manufacturers in implementing my cabin airflow solution. With issues like the MERS outbreak happening this very instant, it is critical that we start taking action to improve aircraft cabin airflow, so that we could help minimize the damage of a possible future disease epidemic.
That being said, the logistics that lie on the road to implementation is a journey in and of itself. Moving forward, I hope to continue using ANSYS to support my implementation efforts as I engage in ongoing talks with airlines who have already expressed interests in my solution. Needless to say, time is of the essence, and I welcome all others who share a view of this innovation’s potential to get in touch so that together, we can start making a difference as soon as possible for the health of air travelers worldwide.
EDITORS NOTE: On July 7, 2015, we’ll be hosting a LIVE Google Hangout interview with Raymond Wang to further discuss his research and solution. This event will be held on the ANSYS TechTips YouTube Channel at 5 pm Pacific Time. Please follow our social channels to stay on top of this exciting event. If you’d like to submit questions for Raymond, please use #RWANGLIVE on Twitter and we’ll try to incorporate your questions for him.