"The aim of this project is to forge a physical understanding of the transitions and of the turbulent flow of semi-dilute/dense non-colloidal suspensions, for different particle features and suspending fluids.It is estimated that 10% of the world energy consumption is due to the transport and handling of granular materials of which particle suspensions are an important part. A deep understanding of the mechanisms underlying the flow of particle suspensions, the transition to turbulence and the turbulence characteristics is crucial for many important practical applications involving engineered complex fluids, such as pastes and paper pulp. A better prediction and control of the flow of suspensions will therefore have a huge impact.Complex fluids are multiscale by nature where the physics at the microscale affects the macroscopic behaviour of the flow and vice versa giving rise to surprising and spectacular phenomena as well as making this one of the most important practical problem still to solve. Investigating the mechanisms by which the system microstructure determines the macroscopic flow properties and vice versa will not only give valuable insights into the nature of flowing suspensions but also will also lead to new ways to model and control it. Future generations of engineering CFD tools will have to contain models for complex suspensions. The fundamental approach proposed here, combined with challenging scientific and engineering examples backed up by experimental evidence, will make this possible and demonstrate it to a wider engineering community. The proposed project is based on highly accurate simulations of multiphase flow systems and state-of-the-art experiments. Such a holistic approach will enable us to understand the underlying mechanisms of instabilities and suspension turbulence and to develop accurate criteria for their prediction far in advance of what we could achieve with either approach separately."