Journal of Thermal Science Vol.22, No.4 (2013) 287−293 Received: March 2013 Makoto Yamamoto: Professor www.springerlink.com DOI: 10.1007/s11630-013-0626-x Article ID: 1003-2169(2013)04-0287-07 Multi-Physics CFD Simulations in Engineering Makoto Yamamoto Tokyo University of Science, Department of Mechanical Engineering 6-3-1 Niijuku, Katsushika-ku, Tokyo, 125-8585, Japan © Science Press and Institute of Engineering Thermophysics, CAS and Springer-Verlag Berlin Heidelberg 2013 Nowadays Computational Fluid Dynamics (CFD) software is adopted as a design and analysis tool in a great number of engineering fields. We can say that single-physics CFD has been sufficiently matured in the practical point of view. The main target of existing CFD software is single-phase flows such as water and air. However, many multi-physics problems exist in engineering. Most of them consist of flow and other physics, and the inter- actions between different physics are very important. Obviously, multi-physics phenomena are critical in devel- oping machines and processes. A multi-physics phenomenon seems to be very complex, and it is so difficult to be predicted by adding other physics to flow phenomenon. Therefore, multi-physics CFD techniques are still under research and development. This would be caused from the facts that processing speed of current computers is not fast enough for conducting a multi-physics simulation, and furthermore physical models except for flow physics have not been suitably established. Therefore, in near future, we have to develop various physical models and ef- ficient CFD techniques, in order to success multi-physics simulations in engineering. In the present paper, I will describe the present states of multi-physics CFD simulations, and then show some numerical results such as ice accretion and electro-chemical machining process of a three-dimensional compressor blade which were obtained in my laboratory. Multi-physics CFD simulations would be a key technology in near future. Keywords: Computational fluid dynamics, Multi-physics, Engineering problems Introduction Nowadays Computational Fluid Dynamics (CFD) software is adopted as a design and analysis tool in a great number of engineering fields such as automobile, turbo-machinery, aerospace, ship building, medical engi- neering, electric engineering, civil engineering, architec- ture and many others. We can say that single-physics CFD has been sufficiently matured in the practical point of view. The main target of existing CFD software is sin- gle-phase flows such as water and air. Every single-phase flow includes single physics (i.e. fluid dynamics or aerodynamics). On the other hand, many multi-physics problems exist in engineering as well as science. Most of multi-physics phenomena consist of flow and other physics, and the interactions between different physics are very important. Fluid/structure interaction, solid/ liquid, gas/liquid and gas/solid two-phase flows, conju- gate heat transfer, reactive and combusting flows, ice accretion, particle deposition, erosion, chemical machin- ing and so on are all multi-physics phenomena related to flow physics. Obviously, such phenomena are critical in developing machines and processes. However, from the technical view point of CFD, a multi-physics phenome- non seems to be very complex, and it becomes so diffi- cult to be predicted by adding other physics to flow phe-