Flows through an open cross-flow-type nano-hydraulic turbine are numerically simulated to investigate the effects of the clearance Hc between the rotor and the ground on the turbine performance. A two-dimensional part...Flows through an open cross-flow-type nano-hydraulic turbine are numerically simulated to investigate the effects of the clearance Hc between the rotor and the ground on the turbine performance. A two-dimensional particle method is employed, which was successfully used for flow simulations of impulse-type and open cross-flow-type nano-hydraulic turbines in the authors＇ previous works. When the clearance Hc is smaller than a critical value, the simulated turbine performance decreases with decreasing Hc, in good agreement with the experiment. The simulations make it clear that such a reduction of turbine performance is attributable to an increase in the circumferential component of the water velocity at the rotor outlet. The simulations also demonstrate that the effect of the tip speed ratio of the rotor on the relation between Hc and turbine performance can be analyzed.展开更多
文摘Flows through an open cross-flow-type nano-hydraulic turbine are numerically simulated to investigate the effects of the clearance Hc between the rotor and the ground on the turbine performance. A two-dimensional particle method is employed, which was successfully used for flow simulations of impulse-type and open cross-flow-type nano-hydraulic turbines in the authors＇ previous works. When the clearance Hc is smaller than a critical value, the simulated turbine performance decreases with decreasing Hc, in good agreement with the experiment. The simulations make it clear that such a reduction of turbine performance is attributable to an increase in the circumferential component of the water velocity at the rotor outlet. The simulations also demonstrate that the effect of the tip speed ratio of the rotor on the relation between Hc and turbine performance can be analyzed.
