Efficiency evaluation of a ductless Archimedes turbine: Laboratory experiments and numerical simulations

The aim of designing a new hydrokinetic turbine simple, cheap, environmentally friendly and suitable for installation in remote areas is pursued by studying the efficiency of an Archimedes turbine that exploits the kinetic energy of a water stream rather than an upstream-downstream difference in water head. First, the efficiency of a hydrokinetic Archimedes turbine has been studied using laboratory experiments for low TSR regimes. Subsequently, numerical simulations have been run to evaluate the performance coefficient of the turbine only (without frictional losses or blockage augmentation), and to extend the TSR range. Numerical simulations have allowed to produce the efficiency curve of the hydrokinetic Archimedes turbine in both aligned and inclined configurations. The obtained maximum performance coefficients have been compared with those of other hydrokinetic turbines currently in use and inspected through a parametric analysis dedicated to explore the practical applications of the proposed turbine.