报告地点: 罗姆楼十一层学术报告厅

主办单位: 热能系 / 燃烧能源中心

报告题目（一）：Particles in Turbulence

报告人:Prof.Eberhard Bodenschatz, Max Planck Institute for Dynamics and Self-Organization

报告时间：2014-05-05 9:00 a.m.

Introduction toBodenschatz group:

The Fluid Dynamics, Pattern Formation, and Biocomplexity Research Group belongs to Max Planck Institute for Dynamics and Self-Organization in Göttingen, Germany. We are investigating the dynamics of a variety of complex nonlinear systems both experimentally and theoretically. Our interests are currently focused on biocomplexity in cell-biology, Lagrangian properties of fully developed turbulence, pattern formation and spatio-temporal chaos, and the Geodynamics of the earth's crust.

To know more about our current research interests, please go to the following websitehttp://www.lfpn.ds.mpg.de/

报告题目（二）🤬🏌🏻‍♀️：Direct Numerical Simulation of Turbulent Combustion - Fundamental Insights towards Predictive Models

报告人: Dr. Jacqueline H. Chen, Sandia National Laboratories

报告时间🏷：2014-05-05 10:30 a.m.

Abstract of the Lecture:

With rapid increase in computing power, recent petascale direct numerical simulations (DNS) have been performed of canonical turbulent configurations to glean physical insight into ‘turbulence-chemistry’ interactions in combustion and to provide validation data for the development of coarse-grained engineering models. The role of DNS is illustrated through two examples where turbulence is affected by combustion. In the first example, DNS of turbulent hydrogen/air premixed flames interacting with intense shear driven turbulence in a planar jet is used to study inter-scale energy transfer through one-dimensional auto- and cross-correlation functions and corresponding spectra of reactive scalars from the turbulent premixed flames. Balance equations for the density weighted turbulent kinetic energy and scalar fluctuation spectra for reacting flows are derived and used to understand the physical processes unique to reacting flows. In the second example, DNS focused on the characterization of flashback for premixed, preheated hydrogen-air flames in turbulent boundary layers show that one of the principal assumptions behind the widely-used flashback model of Lewis and Von Elbe is flawed. In this model the effect of the premixed flame on the approaching flow is negligible, while the DNS and also recent experiments reveal the presence of flow reversals, induced by the combustion in the viscous layer located immediately upstream of flame surface regions that are convex towards the reactants. This finding suggests a radically different picture about the mechanism of boundary layer flashback and a need for a near-wall flame propagation model that correctly accounts for the combustion effect on the oncoming turbulence. Finally, the challenges and prospects for DNS of turbulent combustion at the exascale will be discussed in the context of co-design of numerical algorithms, the software stack, and computer architectures.