Abstract: This study investigates the influence of blade inclination angle θ on the performance and internal flow characteristics of a disc pump. Nineteen impeller models with blade angles ranging from -45° to 45° were developed, and a combined approach of numerical simulation and experimental validation was employed. Simulations reveal that θ significantly influences both pump head and efficiency, and the positive θ models have better performance than the negative ones. The fitted head and efficiency curves reveal the pump performance reaches its optimum at a θ of around 30°, with the head of 22.37 m and the efficiency of 37.5%. By comparing the internal flow fields between the original model and the optimized model of θ = 30°, we find the latter enjoys a more uniform pressure distribution on the front cover plate in both the blade and non-blade zones, resulting in lower energy loss. And, the pressure-boosting capability in the blade zone near the rear cover plate is stronger. Analysis on turbulence kinetic energy and vortex distribution further indicates that modification on the blade angle decreases turbulence kinetic energy in the flow, and effectively suppresses vortex formation and flow instability, thereby improving pump performances. Flow patterns in the impeller section shows that the design of inclined vanes reduces the local impact angle to the vane working surface, which brings about improvement on the local flow state and a considerable reduction of energy loss.

Key words: blade angle, performance improvement, internal flow field, numerical simulation, turbulence kinetic energy, vortex distribution