• October 15, 2018
  • 4:00 p.m.
  • 320 New Classroom Building
  • Dr. Aleksandar Jemcov, Notre Dame
  • Faculty Host: Dr. Eric Paterson
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  • Abstract: Over the past thirty years, the significant design improvements of gas turbine efficiency have brought the state of the propulsion technology to the point where only the incremental advances in gas turbine efficiency are possible. Improvements in the adiabatic efficiency of compressors, turbines, and combustors are of the order of the fraction of percent and only breakthroughs in material science or adoption of the new propulsion concepts will enable significant improvements in gas turbine propulsion technology. One consequence of the current state of the art in the design of rotating turbomachinery components is the rising need for more accurate computational predictions. The classical Reynolds averaged simulations no longer can predict the flow in the components of the gas turbine to sufficient accuracy to enable incremental design changes. At the same time, the promise of the Large Eddy Simulation to replace the time-averaged one did not materialize due to a significant computational cost that makes LES too expensive for the practical simulations with relevant Reynolds numbers. Therefore, a different path is needed in order to enable simulations of the sufficient fidelity so that designers can achieve their incremental changes in the design. One possible path of achieving the stated goal is to develop a Scale Resolving Simulation (SRS) turbulence models that approach the fidelity of LES at a significantly lower computational cost. The desirable properties of such model include the ability to adopt the fidelity of the simulation based on the local mesh density, physical consistency in the limits of both low and high wave numbers in the turbulence spectrum, and to maintain low computational cost. In this talk, we describe several SRS models developed at the Notre Dame Turbomachinery Laboratory and their validation using the experimental data sets collected in the laboratory over the past ten years. Validation examples include canonical problems as well as detailed compressor and turbine simulations.
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  • Bio: Professor Jemcov has graduated from the University of Belgrade with BSc, MSc, and Ph.D. degrees in aerospace engineering focusing on combustion instabilities in rocket propulsion. He has over twenty years of experience working for Pratt & Whitney Canada, Fluent Inc., and ANSYS Inc. While at Pratt & Whitney Canada, he has worked as a combustion aerodynamicist on a number of engines that are still in service today. His work in Fluent Inc. and ANSYS Inc. focused on the development of the numerical and physical models in the flagship product Fluent. Professor Jemcov joined the Aerospace and Mechanical Engineering Department at the University of Notre Dame in 2011 in the capacity of the Research Assistant Professor. He teaches several classes including Aircraft Propulsion and Aerospace Dynamics. In addition to his duties within the aerospace and mechanical engineering department, he currently serves in a concurrent position as the Associate Director for Computational Sciences at the Notre Dame Turbomachinery Laboratory where he leads the group of research scientists, and he is responsible for all computational projects within the laboratory. His area of interest includes rocket and gas turbine propulsion, high-fidelity turbulence models, spectral finite element methods, and general numerical methods in continuum mechanics.