LAUSR

Compressed Air Energy Storage (CAES) System is a significant technology for renewable energy utilization. As a power generation device in the system, the blade of radial inflow turbine has a lower aspect ratio and tip leakage loss is larger. A novel blade profile based on NACA standard airfoil is proposed and optimized by orthogonal design coupling Computational Fluid Dynamic (CFD) model. The effect of NACA-based profile parameters on isentropic efficiency is obtained and the tip leakage flow loss mechanism is revealed. The applicability of blade with optimal NACA-based profile is investigated under off-design operation and non-uniformity inlet conditions. Results indicate that the optimal NACA-based profile has larger leading edge inscribed circle radius and smaller thickness at trail part of blade which reduces the tip leakage flow velocity near trailing edge and weakens the mixing of the leakage flow and mainstream. As a result, the efficiency of the radial inflow turbine can be increased by 1.26%, 1.20% and 1.99% when the tip clearance are 2%, 4%, and 8%, respectively. The blade with optimal NACA-based profile also increases the efficiency of the radial inflow turbine at different pressure ratios and inlet attack angles and satisfies the deformation and structure strength requirement.