Blade Design Method Research Articles

Application of an inverse cascade design method to an axial fan.

In order to demonstrate the applicability of an inverse cascade design method for blade design for an axial turbomachine, rotor and stator blades of a single stage axial fan are designed and tested. This design concept, proposed in the previous reports, is based on an inverse boundary layer method and an inverse cascade method. Overall performance and the rotor exit flow field are measured and are compared with a conventional fan designed using NACA 65 series cascade. The inversely designed fan obtains higher efficiency and a wider operating range compared with the conventional one. The midspan wake of the rotor blade in the trailing edge region reveals an extremely low velocity defect, a low wake shape factor, and low momentum thickness. boundary layer separation on the rotor blade suction surface seems to be avoided and the losses are low. The experimental results show the validity of the practical aplication of the inverse design concept, especially for rotating blades.

Aerodynamic Approach to the Design of Blade Profiles Suitable for Compressor Cascade : 2nd Report, Inverse Boundary Layer Theoryand Blade Design Method

境界層理論の逆問題を解くことにより翼背面においてはく離を生じることのない好適な背面流速分布を導く一手法を示したのち,流速分布を規定するパラメータと翼列性能の定性的関係を速度三角形に依存しない形で整理し明らかにした.そして,これと前報で提案した翼列の逆問題の解法を結びつけることにより,与えられた速度三角形を最小の損失で実現する減速翼列用翼形の空気力学的設計法を提案した.

Presentation of a Blade-Design Method for Axial-Flow Turbines, Including Design and Test Results of a Typical Axial-Flow Stage

A method is presented to determine the shape of stationary nozzle blades and rotor blades for an axial-flow-type turbine in a generally consistent manner based on the concept of aerodynamic blade loading. The mean blade load is a typical design parameter which predominantly determines the blade curvature. It depends in particular on the rate of change of momentum across the blade row. By applying the design method, airfoil shapes are obtained which satisfy the momentum requirements regardless of what blade-load distribution is assumed as long as the mean blade load remains constant. A specific application of the design method is described and test data are presented which show that good agreement between design goal and test results was achieved.