Computational multiphysics refers to the study of coupled physicochemical processes using computational methods. Such processes typically combine laminar or turbulent multiphase flow, reaction and transport of chemical species in multicomponent mixtures, transport of charge or small particles, heat transfer, sound wave propagation and various kinds of phase change (e.g. condensation, precipitation, etc.) Industrially relevant multiphysics always take place in the complex geometries of process equipment (reactors, separators, turbines, etc.) or porous materials (both natural and man-made). More often than not, the coupling of physicochemical processes takes place across very disparate scales in space and time. The confluence of these factors severely limits the effectiveness of experimental approaches to industrial design, optimization and control. Computational multiphysics tackle this complexity in terms of high-fidelity mathematical models, numerical methods and computational tools. The simulations guide experimental testing and prototyping, typically resulting in significantly reduced capital costs, faster time-to-market, and minimization of safety issues compared to experimentation alone.