March

ME Course Column: Mechanics of Snow

Anonymous — Thu, 17 Mar 2022 15:45:29 +0000

ME Course Column: Mechanics of Snow Anonymous (not verified) Thu, 03/17/2022 - 09:45

Rachel Leuthauser

The ME Course Column is a recurring publication about the unique classes and labs that mechanical engineers can take while at the University of Colorado Boulder. Follow the series to understand the core curriculum, discover elective course options and learn the broad applications of mechanical engineering skills.

Most mechanical engineers will work with materials such as metals, polymers, ceramics and composites during their careers. However, a course taught by Department of Mechanical Engineering Professors Francois Barthelat and Franck Vernerey asks students to draw inspiration from another material – snow.

“I am a backcountry skier and as such, you have to learn a lot about avalanches and take courses for safety,” Vernerey said. “You realize there is so much mechanics involved with snow.”

Above: Professors Francois Barthelat and Franck Vernerey
Header image: Barthelat and Vernerey guide students through a slide test.

MCEN 4228/5228: Mechanics of Snow motivates students to look at their environment and the materials around them in an analytical way. The idea behind the course is to teach students the science behind certain phenomena by looking at the fundamentals of snow and ice from the atomic level to the mechanics of the snowpack.

“Snow in itself is an interesting material to study, you do not necessarily think of looking at snow in the context of mechanics of materials, but there is a lot to learn from this approach,” Barthelat said. “This is a great a way to expose students to state-of-the-art experimental and modeling techniques that people use in engineering.”

While studying the properties of natural versus artificial snow, the mechanics of sliding on skis and snowboards, or the conditions that trigger avalanches, students also master theoretical tools such as fracture mechanics and heat transfer. They also learn about the relationship between molecular structures, thermodynamics, and micromechanics, including viscoelasticity.

The professors explained that applying these critical engineering concepts to snow helps students better understand the information. It allows them to see that these concepts are real and happening in our environment.

“We often teach mechanics of materials and students are not always connected to the course because they have not worked with the materials before,” Vernerey said. “They learn the equations but may have difficulties connecting them to the real world. This course allows them to better connect because they already have an idea about the material. They are much more motivated to learn.”

Mechanical engineering students conduct slide tests on a snowboard.

Students in Mechanics of Snow conducted their own research out in the elements on March 10, after Boulder received about four inches of snow. They measured the densities of the fresh and old snow, assessed their compressive strength and calculated the snow’s coefficients of friction on skis and snowboards.

The class will take one more field trip outside to conduct strength and fracture tests on the snow before completing final projects to wrap up the semester. Some students are looking at avalanche conditions, while others are studying the impact mechanics of snowballs or snow construction such as igloos and walls.

“A big takeaway from this course is that students will be exposed to a vast number of topics in engineering and physics,” Barthelat said. “If they need these in their professional life later on, they know that the concepts exist and where to find more information.”

Mechanics of Snow is a technical elective open to upper-level undergraduate and graduate mechanical engineering students.

View all the Mechanical Engineering Technical Elective Courses

MCEN 4228/5228: Mechanics of Snow motivates students to look at natural materials in an analytical way. The idea behind the course is to teach students the science behind certain phenomena by looking at the fundamentals of snow and ice from the atomic level to the mechanics of the snowpack.

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Alumni Spotlight: Sreyas Krishnan - Helping launch ULA rockets into space

Anonymous — Mon, 14 Mar 2022 14:42:00 +0000

Alumni Spotlight: Sreyas Krishnan - Helping launch ULA rockets into space Anonymous (not verified) Mon, 03/14/2022 - 08:42

Rachel Leuthauser

Sreyas Krishnan (MSMechEngr'16) stands in front of ULA's Atlas V rocket.

Mechanical engineering alumnus Sreyas Krishnan has played a critical role in United Launch Alliance’s (ULA) latest Atlas V rocket launch, which carried another weather satellite into space on Tuesday, March 1.

Krishnan (BSMechEngr’12, MSMechEngr’16) supported the production and launch for the rocket’s first stage propulsion systems as the primary Booster Propulsion Tiger. This meant that he tracked the rocket through assembly, test and launch, and provided technical support throughout the process.

The NOAA-NASA GOES-T weather satellite will track destructive wildfires, lightning, Pacific Ocean-based storms, dense fog and other hazards that threaten the U.S. West Coast, Hawaii and Alaska.

Serving as a Booster Propulsion Tiger is one of the many roles Krishnan takes on as a Propulsion Systems Design Engineer at ULA. He said the job allows him to constantly learn and see new things to expand his knowledge base. It is a career path that he has been dreaming about since he was a kid whose parents are also University of Colorado alumni.

“��ý�Ļ��Ʒ was my dream school growing up in South Denver, so being a Buff is everything to me,” Krishnan said. “One of my early inspirations to work in aerospace was Dr. Kalpana Chawla, who was the first woman of Indian descent to go to space. She was also a ��ý�Ļ��Ʒ alumna. She meant a great deal to me as the son of Indian immigrants and CU grads.”

Once he was at ��ý�Ļ��Ʒ, Krishnan just had to choose the major that would propel him to his dream career. He shared with us why mechanical engineering was the path he took and how valuable his education and experience as a Buff has become.

Tell us about your background. What inspired you to become a mechanical engineer?

I was always interested in physical systems as a kid, but I wasn’t sure that I wanted to study mechanical engineering until a couple months into my freshman year at ��ý�Ļ��Ʒ. My Intro to Engineering course took us on a field trip to Ball Aerospace in Boulder and I was able to catch a glimpse of the Kepler Telescope while it was still onsite. I knew immediately that mechanical engineering was the major for me. I was so inspired by the idea that I could help design, develop or operate immensely complex physical systems. Not long after that, I started working on projects with the Colorado Space Grant Consortium (COSGC), including a high-altitude balloon payload and a 3U CubeSat bus, which set the stage for my future career path.

What is your day-to-day like at United Launch Alliance (ULA)?

The Delta IV Parker Solar Probe in Cape Canaveral.

My role as a Propulsion Systems Design Engineer at the Centennial, Colorado design center has two different flavors.

Component Engineer: I am the certified responsible engineer (CRE) for all the solenoid-operated valves used on ULA rocket propulsion systems and a CRE-delegate for several other flight-critical components like vent valves, pneumatic regulators and pressure vessels. I like to call this a ‘whatever, wherever, whenever’ role because you are responsible for the entire lifecycle of a component from pre-assembly to in-space operation. Over the years, this role has touched almost every discipline covered in the mechanical engineering curriculum, has allowed me to wear a ton of different hats and has provided me with the opportunity to learn from some incredible people. In addition to product ownership, I also led the development and qualification programs of six flight-critical components used on the new Vulcan Centaur rocket alongside my industry partners. These programs are exciting but very demanding since propulsion system components need to perform flawlessly through a multitude of challenging environments such as extreme temperatures, shock, vibration and heavy usage to ensure mission success.
Tiger Team: I support production and launch for the first stage propulsion systems of the Atlas V and Delta IV rockets. This involves following each vehicle through its assembly, test and launch while helping to resolve any issues that occur along the way. This role also brings me out to the launch sites in Cape Canaveral, Florida and Vandenberg, California to complete final inspection walkdowns inside and around the vehicle, then provide on-console engineering support in the ‘back room’ of our Launch Control Center on the day of launch.

My favorite mission so far was the Parker Solar Probe, which we launched for NASA on a Delta IV Heavy rocket back in 2018.

How have the mechanical engineering skills you gained at ��ý�Ļ��Ʒ helped your career?

The engineering program had an enormously positive impact on my career. As an undergraduate from 2008 to 2012, ��ý�Ļ��Ʒ provided me with numerous opportunities to spend quality time in the CAD lab and machine shop in support of various engineering projects for COSGC, as well as regular course work such as Component Design and Senior Design. I credit this experience with giving me a fundamental understanding of design and manufacturing concepts.

That said, my time in ��ý�Ļ��Ʒ’s Graduate Design Program from 2014 to 2016 was on another level. In those two years, I worked on an incredible array of projects. We built an autonomous, nerf-dart firing robot, a vascular closure device prototype, a single-pill dispensing pill bottle lid and even a 3D-printed toy Ralphie with moving legs. However, the project that literally propelled me towards my current role was a ULA-sponsored, 3D-printed thruster design project called Additive-Manufactured Aerospike Reaction Control System (AMARCS). That was my first exposure to fluid/propulsion systems design, and I was HOOKED!

What advice do you have for current mechanical engineering students?

Krishnan and the AMARCS team with ��ý�Ļ��Ʒ's mascot Chip.

Take advantage of every opportunity afforded to you by the school – there are a ton of them! That means picking your professors’ brains at office hours, signing up for interesting extracurricular projects, doing lab research and learning new hard skills. This is your best opportunity to fully immerse yourself in a broad base of knowledge, so use it as leverage to become the best version of yourself.

Build meaningful connections with people and don’t be afraid to ask for help. As you go through various highs and lows, both in your coursework as well as in life, those people will help you persevere. It takes effort to maintain those relationships, but trust me, it’s worth it!

Develop critical thinking skills in a relatively low-consequence environment. Learning to gather data and documenting well-reasoned interpretations of said data is an essential skillset for any confident decision maker.

HAVE FUN!!! Boulder is amazing. Don’t graduate with regrets about missed opportunities.

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