汇报时间：2018年9月15日9:30

汇报地点：曲江校区西二楼315

汇报人：闫素娜

PART 1: Reflections on Two Years at DTU as a CSC Visiting Scholar

Abstract

The China Scholarship Council (CSC) is an institution aiming to improve the training of creative and distinguished postgraduates and enhance the development of China’s higher education. Over the past several years, CSC has sponsored many talented Chinese students for overseas study. From September 2016 to August 2018, I was sponsored by CSC to perform two-year research work at Department of Mechanical Engineering, Technical University of Denmark. During my stay, I worked together with Prof. Ole Sigmund and Senior researcher Fengwen Wang on the topology optimization of heat conduction structures and conjugate heat transfer problems. We found that the commonly seen tree structures are not optimal for heat conduction, which is contrary to common belief and has made a stir in the related research field. More details on this work will be given in my presentation. A brief introduction of DTU and the TopOpt group in which I worked will also be included.

Bio Sketch of Ms. Suna Yan

Suna Yan is a fifth year Ph.D. student in Professor Jun Hong’s group in the School of mechanical engineering at Xi’an Jiaotong University, Xi’an, China. She is sponsored by the China Scholarship Council to conduct a two-year research as a visiting PhD student during September 2016-August 2018 under the supervision of Professor Ole Sigmund in the Department of Mechanical Engineering at the Technical University of Denmark. Her research focuses on the topology optimization of heat conduction structures and conjugate heat transfer problems.

PART 2: On the non-optimality of tree structures for heat conduction

会议名称：ECCM-ECFD 2018: 6th European Conference on Computational Mechanics, 7th European Conference on Computational Fluid by Dynamics

会议时间：June 11-15, 2018

会议地点：Glasgow, United Kingdom

会议简介：

The 6th European Conference on Computational Mechanics (Solids, Structures and Coupled Problems) and the 7th European Conference on Computational Fluid Dynamics is jointly organized in Glasgow, UK to celebrate the 25th Anniversary of the European Community on Computational Methods in Applied Sciences (ECCOMAS).

ECCM-ECFD 2018 in Glasgow is hosted by The University of Glasgow and The University of Edinburgh, in partnership with the UK Association for Computational Mechanics in Engineering (UKACM). The ECCOMAS Conference on Computational Solid and Structural Mechanics (ECCM) and the ECCOMAS Conference on Computational Fluid Dynamics (ECFD), together with the ECCOMAS Congress, constitute the three main scientific events of ECCOMAS organized every four years, on even years, which attract approximately 5000 participants in total.

会议交流工作:

Oral presentation: On the non-optimality of tree structures for heat conduction

参加论文信息:

Title: On the non-optimality of tree structures for heat conduction

Author: S. Yan, F. Wang and O. Sigmund

Abstract:

This work revisits topology optimization of heat conduction structures for minimum thermal compliance and minimum maximum temperature, respectively. For both optimization problems, volume-to-line and volume-to-point structures are optimized based on three material interpolation models describing different design spaces regarding the relation between material density and effective conductivity. Specifically, the material models are optimal rank-1 microstructures scheme, penalized density approach and variable thickness sheet model. In contrast to common understanding, this work shows that lamellar needle structures, rather than commonly seen tree structures, provide the (near-)optimal topologies for heat conduction. This conclusion still holds when a minimum length scale is imposed for both high and low conductive regions. The suboptimal designs obtained by penalized density approaches as well as the majority of the results from the literature, demonstrate how easy it is for standard optimization formulations to get stuck in local minima. Initial guesses projected from the designs of rank-1 laminates help circumvent local minima. Alternatively, one must resort to very slow continuation approaches or an additional local volume constraint. For minimum thermal compliance and min-max temperature problems under single load conditions, optimal designs can be realized by rank-1 laminates. By contrast, the variable thickness sheet model is optimal only for the self-adjoint minimum thermal compliance problem.