This work reports radial patterns and velocity profiles of fluid-particle suspensions rotating in a fully filled horizontal cylinder using the technique of Particle Image Velocimetry. Dilute and mono-dispersed suspensions of non-Brownian settling as well as floating particles were considered. An analysis of the effect of particle shape on the flow patterns is provided. This was carried out by comparing the suspensions of spherical and cylindrical particles. Impact of particle shape on the particle-fluid interaction in determining the flow structure is more pronounced at lower speeds. Analysis of the velocity profiles showed a resemblance of the buoyant and settling suspensions phases. Despite the similar features observed, a difference was noted when the centrifugal forces dominate. Our experimental results are in good qualitative agreement with the previous experiments and simulations. Through a detailed investigation of velocity field we have established the strong relationship between the phase transition and rotational speed.