Multiphase flow systems occur in a variety of industrial applications and are prevalent in nature. The focus of this dissertation is on experimental investigation of such flows in laboratory scale setups for the purpose of better understanding the fundamentals, validation of numerical simulations and models, and derivation of correlations for practical applications.

Two major types of flow were studied including a gas-liquid two phase flow inside a Taylor-Couette vortex reactor and a solid-liquid flow of water flow around a train of solid spherical particles inside a square duct. For the Taylor-Couette system, characterization of mass transfer from gas into liquid phase was the main focus. In addition, the size and shape of the bubbles were measured and observed in order to quantify the mass transfer coefficient. This was followed up with the study of the effect of interfacial tension on the system using ethyl alcohol as a surfactant.

The duct flow around a train of particles was studied in order to enable observation of the interaction between arrangements of particles and the flow field. The velocity field data from Particle Image Velocimetry (PIV) experiments served as a validation case for Particle-Resolved Direct Numerical Simulation (PR-DNS). The number of spheres in the train arrangement was varied as well as their distance. The work performed for the two different setups are separately introduced in the following.