The special volume concentrates on most recent developments, related to convective transport phenomena modeling with computational and numerical methods for fluid flowing through passages with complex geometries. It contains contributions in the field of numerical simulation of complex fluid flows, e.g. multiphase flows containing soft and solid particles. Advances using the meshfree Smoothed Particle Hydrodynamics (SPH) method, high-order compressible flows and turbulent spiral double-pipe flow in heat exchangers, rotating pipe flow, diverging pipes using numerical simulation with different numerical methods are presented. A comparison between different fluid solvers, like Fluent and OpenFOAM, for bubbly flows, investigations of design of microchannels for nanofluid flows with a focus on electronic applications as well as entropy generation is complemented by a review on fluid-structure interaction in porous media as well as investigations on the up-scaling method called asymptotic homogenization. A link to applications is made by analysis of PCM and porous media, like humidifier, for PEM fuel cell applications or turbine performance and permeation in porous membranes with comparison to experiments.