Professor Kwang-Yong Kim, Department of Mechanical Engineering, Inha University, Incheon, Republic of Korea
报告一：“Development of Passive Micromixers”
Mixing of fluids in channels of sub-millimeter dimensions is a fundamental operation required on microfluidic devices. The flow in such devices is laminar which makes it difficult to mix the fluids in a simple smooth microchannel. A wide variety of micromixers are operating on different mixing principles. Micromixers can be broadly classified as active and passive micromixers. Most of the passive micromixers are based on shape modification of the microchannels to produce a specific flow pattern which enhances mixing. The speaker has developed several innovative methods to enhance mixing in passive micromixers mostly using numerical and optimization techniques in last decade. Based on these researches, a review on enhancement of mixing in different types of passive micromixers will be presented in this seminar. The focus will be on recent developments on passive micromixers operating under steady and unsteady flows. Computational fluid dynamics has proved to be a reliable tool for analyses of flow structures and mixing behavior in micromixers. To study the flow dynamics and mixing performance, Navier-Stokes equations and a diffusion-convection model for species transport are solved, respectively. A variance-based method was employed to evaluate the mixing performance of the micromixers. Design optimization coupled with 3D Navier-Stokes analysis has become an efficient tool for the design of micromixers. New concepts of various mocromixers are introduces with optimization of the geometries to maximize the mixing in those micromixers.
报告二：“Optimization of Thermo-Fluid Systems Using Surrogate Modeling”
In most of thermo-fluid systems, geometry of the system is an important factor to determine the system performance. Thus, optimization of the geometry is an essential job to enhance the performances of various thermo-fluid systems. In this seminar, surrogate-based optimization techniques with a three-dimensional Reynolds-averaged Navier-Stokes analysis and their applications to practical designs will be introduced. Numerical optimization methods are regarded as general design tools and offer a number of advantages, including automated design capability, varieties of constraints, and multidisciplinary applications. However, due to large computing time, coupling with Navier-Stokes analyses has recently proven practical with the aid of high performance computers. Among various optimization algorithms, the surrogate modeling technique has become widely used in engineering applications due to its intrinsic advantages. The surrogate models being widely used in multidisciplinary optimization are advantageous in two important aspects: (i) computational economy, which necessitates as few data-points as possible for constructing a surrogate model, and (ii) accuracy in representing the characteristics of the design space. Applications of these optimization techniques to designs of various thermo-fluid systems such as heat exchangers, gas turbine cooling systems, micro heat sinks, nuclear reactor cooling systems, will be introduced.
Kwang-Yong Kim received his B.S. degree from Seoul National University in 1978, and his M.S. and Ph.D. degrees from the Korea Advanced Institute of Science and Technology (KAIST), Korea, in 1981 and 1987, respectively. He is currently an Inha Fellow Professor in the Department of Mechanical Engineering of Inha University, Incheon, Korea. Professor Kim is also the current editor-in-chief of the International Journal of Fluid Machinery and Systems, and the chairman of the Asian Fluid Machinery Committee. He served as the editor-in-chief of the Transactions of Korean Society of Mechanical Engineers and president of Korean Society for Fluid Machinery. He is also a fellow of the American Society of Mechanical Engineers (ASME) and an associate fellow of the American Institute of Aeronautics and Astronautics (AIAA).
He is interested in applications of the numerical optimization techniques using various surrogate models and computational fluid dynamics to the designs of fluid machinery, heat-transfer augmentation devices, micro heat sinks, micro mixers, coolant channels in nuclear reactors, etc. He has published 290 peer-reviewed journal papers, and presented more than 400 papers at international/domestic conferences.