For over 100 years, propellers have been the propulsion method of choice for aircraft, helicopter, and boat manufacturers. With the rise of multi-rotor technology, the limitations of this ancient method of propulsion have placed a glass ceiling on emerging industries such as drone delivery and “flying cars.” Besides the obvious safety issues, the faster that a blade rotates the more inefficient it becomes at transferring energy into thrust. A key reason for this upper limit on economies of RPM is that the faster a blade spins, the more prominent the vortex geometry becomes in the mass flow, which is parasitic to propulsion. This constrains both payload and range. Continue reading
Smoking meat (and other food) in a barbecue smoker doesn’t sound complicated, but there are more factors at work in producing delicious food than you would expect. Barbecue enthusiast Travis Jacobs, president of Jacobs Analytics, was aware that in windy conditions the air flow through the bottom inlets and the top outlet vents of a smoker can be variable, leading to internal temperature gradients and swirling air that removes smoke and makes a less savory product. He wanted to make a smoker that could smoke food to perfection in any conditions. Unlike most of us non-engineer weekend barbecuers, he turned to computational fluid dynamics (CFD) simulations to solve this problem.
If you’re not familiar with topological or topology optimization, a simple description is that we are using the physics of the problem combined with the finite element computational method to decide what the optimal shape is for a given design space and set of loads and constraints. Typically our goal is to maximize stiffness while reducing weight. We may also be trying to keep maximum stress below a certain value. Frequencies can come into play as well by linking a modal analysis to a topology optimization.
Why is topology optimization important? First, it produces shapes which may be more optimal than we could determine by engineering intuition coupled with trial and error. Second, with the rise of additive manufacturing, it is now much easier and more practical to produce the often complex and organic looking shapes which come out of a topological optimization. Continue reading
EnSight, the leading post-processor for Computational Fluid Dynamics (CFD) data is now part of ANSYS. In the two decades since its launch, EnSight has taken off like a multistage rocket. Here is the story.
I grew up in that magical era when NASA used multi-stage rockets to carry Apollo astronauts to the moon and back. As a toddler I learned to count backwards from 10, 9, 8, 7, 6 … because that’s what I heard Mission Control say. I dreamt of being an astronaut, studied aerospace engineering and started my career at NASA’s Johnson Space Center in Houston, Texas. I met my lovely wife there, blocks from the NASA gates. Her parents still live next door to Buzz Aldrin’s Apollo era house. I used to store my lunch in the Mission Control fridge while working on my space shuttle aerodynamic simulations in the support room next door. So maybe it’s natural for me to think in rocket terms. Continue reading
Nuclear power is a key player in the future of clean energy, and multiple companies are pursuing new technologies to maximize nuclear’s contribution to the clean energy space. Founded in 2011 and based in Cambridge, MA, Transatomic Power is an advanced nuclear technology startup developing and commercializing a molten salt reactor (MSR), or a nuclear reactor whose fuel is in liquid, rather than solid, form. This technology, originally developed at the Oak Ridge National Laboratory (ORNL) in the 1960’s, offers multiple safety and cost benefits over traditional nuclear reactors, in which the fuel is in the form of solid pellets cooled by water.
Tranatomic’s MSR design builds on the original work at ORNL and adds a few innovative new features that reduce the reactor’s size and, as a result, it’s cost – a huge factor in building new nuclear power plants. Though the development process is a long one, the world needs a larger capacity for clean energy generation, and it’s this ultimate goal that drives the Transatomic team forward. Continue reading
Knights Racing is a Formula SAE team from the University of Central Florida. Formula SAE is an international competition in which students design and build a race car as well as manufacture the car’s components. During the competition, teams are not only assessed based on vehicle performance but in static events like a business case presentation and engineering design review. This year, our team participated in the Formula SAE Michigan competition located at Michigan International Speedway.
Today, after a video call with my kids at home, I feel more relaxed. Usually on long distance business travel, we are always concerned about the family at home. A few years ago long distance voice calls were not only costly but also of poor voice quality. Now, equipped with mobile phones, we can make high-quality audio/video calls and exchange text messages with people around the globe, at little or no cost.
It’s amazing to see the way communication technology has grown over the years. Technologies that seemed like fiction a few years ago, are now becoming reality. These include virtual reality, 3-D hologram and printing, language translation, and mobile streaming audio and video. Continue reading
Every numerical method relies on the accurate choice of models, solver settings, and material parameters in order to be able to mimic real-world behavior. This also applies to Discrete Elements Method (DEM) simulations. You could use standard material properties, but adjusting those material interaction parameters using automated calibration methods is a key step for accurate simulations.
You could use standard material properties, but if you want to simulate reality, it is important to understand that the materials actually vary from site to site. Adjusting those material interaction parameters using automated calibration methods is a key step for accurate simulations. Even with basic materials, friction and restitution coefficients between particles and particles and boundaries have to be adjusted in order to accurately predict the bulk flow behavior. When extra forces come into play, such as adhesion forces, those additional parameters also need to be selected and properly specified. Continue reading
The journey of BiomeRenewables’ PowerConeTM wind turbine started with witnessing a falling maple seed. I was sitting on my deck when I was struck by how slowly the seed was able to fall. As it turns out, maple seeds — for their size — exhibit maximum aerodynamic efficiency; they are able to hit what is known as the Betz Limit — 59.3 percent aerodynamic efficiency. Careful analysis revealed that there is something about the seed’s shape and the way it interacts with the air that allows it to achieve such high efficiency numbers — namely, that it interacts with the oncoming flow at an angle greater than 90 degrees. This is not the case with modern wind turbines, which interact with the wind at perpendicular angles of 90 degrees. Continue reading
All great discoveries and inventions begin with a vision. A vision to make a better product, solve a unique problem or make life easier in some capacity. For centuries scientists and engineers have made tremendous progress in discovering scientific phenomena, or in solving technological challenges. I could write extensively about many of those inventions and discoveries, but there is one I would like to highlight.
In 1928, a Scottish biologist named Alexander Fleming returned to his lab from vacation. As he was sorting through some petri dishes he noticed something unusual. One particular dish had several colonies of bacteria and a cluster of mold. However, there was no bacteria growth near the cluster of mold. Although he did not realize the magnitude of his observation at that moment, he would later be credited with discovering the first lifesaving antibiotic, which he called penicillin. Continue reading