Pietro Ferrero

I was born and raised in the Italian city of Torino at the feet of the mighty Alps. Pretty early in my childhood I realized that my artistic skills were extremely limited, but I was pretty good at dealing with numbers and with stuff that are quantifiable. I got drawn towards science by my curiosity of understanding how the universe works and how it became what it is now (one of my greatest passions is still cosmology). I have always been fascinated by spaceflight and, by the time that the first NASA rover landed on Mars (Pathfinder in 1997), I already decided that I was going to be an aerospace engineer. I followed through with my plans and I obtained both my Bachelor and my Master of Science degrees at the Politecnico di Torino. During my master I became interested in fluid dynamics after attending an outstanding class in compressible flows. It is amazing that such complex phenomena like shock waves, turbulence, acoustic waves are all described by a small set of (relatively) simple differential equations. My master thesis dealt with hypersonic aerodynamics and focused on studying the heating of space vehicles that enter a planet atmosphere: this enabled me to couple fluid mechanics with my old passion for space.

By then I realized I enjoyed doing research very much and I especially liked computational fluid dynamics (CFD) as it is an interesting blend of physics, math and computer science. In 2008 I was ready for a new experience and so I started a PhD at the Aerospace Engineering & Mechanics department of the University of Minnesota, where I am currently staying. In addition of being a terrific human experience, my staying at the U of MN helped me grow professionally a lot. I had the privilege to join Prof. Candler's research group, where I was exposed to some cutting edge methodologies for the numerical simulations of hypersonic and supersonic aerodynamics. By being directly involved in many different projects, I acquired a great expertise in Large Eddy Simulation (LES) of turbulent reactive flows, non-equilibrium aerothermodynamics and rarified flows. I also became acquainted with several methodologies widely used in computational physics, such as Finite Volume / Finite Element, Direct Simulation Monte Carlo and spectral methods.

The core of my research at the U of MN involves using a stochastic method to improve the modeling of the chemical source terms in Large Eddy Simulations (LES) of turbulent reacting flows. High-Reynolds turbulent flowfields present a huge number of temporal and spatial scales and, even with the most powerful computer clusters that are available today and in the near future, it is impossible to resolve all of them. The idea behind Large Eddy Simulations is thus to filter the governing equations and only solve for the filtered quantities. The terms that are filtered out, the so called Sub-Grid Scale (SGS) contributions, are then modeled with some kind of turbulence model. In reacting flows, however, the non-linearity of the chemical source terms make it impossible to develop reliable and universal SGS models for these quantities, so that they are usually ignored in the calculations. In my research I use a stochastic methodology called Filtered Mass Density Function (FMDF) in which the fine-grain chemical composition of the flow is represented by computational particles that are advected throughout the domain. By taking averages of ensemble of these particles it is possible to compute the SGS contribution of the chemical source term directly, without having to resort to any empirical, problem-dependent model. The results I obtained are very promising and show that the use of the FMDF methods are able to drastically improve the accuracy of LES of chemically reacting flows.

For more details about my research click here .

• Ferrero P., Candler G., Filtered Mass Density Function for Variable-Density Turbulent Reactive Flows on Unstructured Meshes, 42nd AIAA Fluid Dynamics Conference, 2012, 10.2514/6.2012-2964.
• Ferrero P., D'Ambrosio D., A Numerical Method for Conjugate Heat Transfer Problems in Hypersonic Flows, 40th Thermophysics Conference, 2008, 10.2514/6.2008-4247.
• Otis C., Ferrero P., Yilmaz S., et al.,SFMDF in US3D for LES of Compressible Flows on Unstructured Meshes, 48th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, 2012, 10.2514/6.2012-4260.