Dr. Dmitry Kolomenskiy is a specialist in fluid mechanics. He received his Ph.D. degree from the University of Aix-Marseille (France), and held academic positions at universities and research institutes in France, Canada and Japan, prior to joining Skoltech. Dr. Kolomenskiy was a postdoctoral fellow at CERFACS (France), McGill University (Canada), Chiba University (Japan), a project scientist at JAMSTEC (Japan), and a specially appointed associate professor at Tokyo Institute of Technology (Japan). In addition, he held visiting fellowships at DAMTP, University of Cambridge (UK), and ESPCI Paris (France). His research concerns mainly with computational fluid dynamics and fluid-solid interaction. His research topics encompass the biolocomotion, vortex dynamics, fluid-solid interaction, and high-performance computing. He develops mathematical models ranging from reduced-order analytical description to direct numerical simulation, on the interface between engineering and biological sciences. He contributed to the development of computational fluid dynamics approaches such as volume penalization and wavelet-based adaptive methods. Besides the work related with the biomechanics, he has been involved in interdisciplinary international collaborative projects with marine biologists, aeronautical engineers, and environmental scientists. His research at Skoltech focuses on the computational fluid dynamics in application to the development of new design and manufacturing processes at CMT.
|Numerical simulation of 3D printing from ceramic pastesCeramic 3D printing is a rapidly developing area of additive manufacturing technologies. When a piece of ceramics is manufactured, it goes through a multi-stage technological process. The geometrical shape of the product needs to remain under control through all stages, as well as the mechanical properties. We focus on the stereolithographic technology, where ceramic particles are diluted into chemical monomers that convert into polymers under laser treatment. Three-dimensional solid parts are grown in a layer by layer fashion. In this ongoing project, we attempt to better understand the limitations, typical defects of this process, and to develop a predictive model that would allow to achieve the best geometrical and mechanical properties of ceramic parts produced by stereolithography.
|3D printing from shape memory polymersShape memory polymers (SMP) can change geometric configuration in response to external stimuli. Our research focuses on the finite-element modelling of 3D-printed SMP parts. In order to capture the shape memory effect of thermally activated polymers, we apply multi-branch constitutive models having two distinct sets of non-equilibrium branches that represent the glassy mode of relaxation and the Rouse modes in the rubbery state. This model is time- and temperature-dependent and applicable for 4D-printing with the fourth dimension referring to time.
|Numerical simulation of spray coatingThe gas dynamic spray is a surface coating technique in which coating is formed by treatment of a metallic substrate by a high-velocity impinging particle-laden jet. This process generates a thin layer with a complex nanocrystalline structure in the impingement zone. Optimization of spraying systems continues evolving from an empirical trial and error process to a model-based approach by virtue of the improving completeness and predictive capacity of mathematical models. In this project with the Laboratory of Thermal Spray and Functional Coatings, we perform direct numerical simulation of the particle-laden flow to explore the effect of unsteady vortical structures and particle agglomeration in the impingement layer.
|Biomechanics and biomimeticsMaterials and designs produced by additive manufacturing share similarities with the biological ones in the respect that they are grown by layers, which allows for a great variety of shapes and multi-component structures. Taking this standpoint, we explore the function of such materials and designs in living organisms, with a focus on mechanisms that enable locomotion in air and in water. Follow the links to learn more about the wings of tiny insects and swimming gaits of aquarium fish.
The next research seminar of the Center for Materials Technologies is scheduled for Wednesday, November 15, 11 AM.
Our speaker is Dr. Bernd R. Noack, Chair of Artificial Intelligence and Aerodynamics (CAIA), School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, China, with the topic “Taming turbulence with many actuators, many sensors and machine learning”.
The seminar will be held in hybrid mode.
Online: Join via https://vc.skoltech.ru/b/ann-ibj-zln-nxx
Numerical Methods in Engineering and Applied Science (6 ECTS)
The course provides students with the understanding and working knowledge of fundamentals of numerical methods used for modeling and simulation of complex phenomena described by ordinary and partial differential equations. The following topics are covered: finite-difference approximation of derivatives; interpolation; integration; steady-state boundary value problems; local and global errors; stability, consistency, and convergence; matrix equations and iterative methods; initial value problems for ordinary differential equations; Runge-Kutta methods; multi-step methods; absolute stability; stiff ODE; numerical solution of PDEs; parabolic problems; hyperbolic problems; method of lines; von Neumann analysis; operator splitting; introduction to spectral approximation.
The course involves hands-on experience with programming (in Matlab or Python) and solving problems on computers. Solid knowledge of undergraduate mathematics including basic understanding of the theory of ordinary and partial differential equations of physics and engineering as well as basic programming skills are required.
Computational Fluid Dynamics (6 ECTS)
Fluid flows are ubiquitous in engineering. Fluid mechanics provides the theoretical foundation to a broad spectrum of engineering applications that range from tiny laboratory-on-a-chip devices to the largest thermal and hydroelectric power plants. The rich dynamics of fluid motion leads to numerous effects that engineers may wish to exploit or suppress. Mathematical description of fluid flows most commonly involves non-linear partial differential equations that make analytical solution impossible or impractical. Therefore, approximate solution using numerical methods has been widely implemented since the advent of digital computers. Nowadays, the Computational Fluid Dynamics (CFD) is a well-established discipline. CFD is widely used in science and engineering alike. It accelerates optimal design and offers important insights in the flow dynamics.
The course will introduce the students to important theoretical and practical aspects of the CFD. It will explain how to describe the fluid flow by partial differential equations with suitable initial and boundary conditions, and how to transform those equations into computer algorithms. A brief overview of general-purpose numerical methods will be provided, with comments on their relevance to the CFD. Then, specialized methods for different types of flows will be introduced. This will be followed by a brief discussion of the advanced topics of fluid-structure interaction, turbulence modelling and high-performance computing. Computer practice classes will allow the students to acquire basic skills of programming simple methods from scratch, get acquainted with existing CFD software packages, develop intuition for distinguishing physical effects from numerical artifacts, and learn to use the CFD wisely.