Session: 10-01 Fan Aerodynamic Design

Paper Number: 154208

Assessment of a New 0.2 Hub-to-Tip Ratio Propeller Fan Design With Rigid-Body Blade Loading 

This paper presents the numerical assessment by means of a new low-order CFD modelling approach of a 0.2 hub-to-tip ratio propeller with specific speed equal to 8.2. The fan implements the rigid body blade loading criterion and it was designed by the authors using the classical “Kahane-Wallis” method. First aim of the work is to give a preliminary feedback on the possibility that the new fan improves the aerodynamic performance of a high efficiency fan designed by the authors in a previous work, which implemented the constant-swirl blade loading strategy. Second aim of the work is to verify the effectiveness of the “Kahane-Wallis” method for the design of very low hub-to-tip ratio fan rotors with rigid-body blade loading distribution. The third and final aim is the presentation of the new low-order CFD modelling approach that the authors conceived for a low-computational-cost preliminary estimate of the aerodynamic performance expected from ISO 5801 Type A performance tests.

To this end, the aerodynamic performance of the new fan design has been simulated by the low-order CFD model, validated against the experimental data of the constant-swirl propeller fan taken as benchmark for this work. This was done after the CFD assessment of another fan designed using the “Kahane-Wallis” method and conceived to try replicating the performance of an existing high-efficiency fan with specific speed equal to 7.3, which implements the rigid body blade loading, and whose aerodynamic performance data are available in the literature.

The results demonstrated that the application of the “Kahane-Wallis” method to very low hub-to-tip ratio fans easily makes it possible to exceed the pressure coefficient achieved by a constant-swirl design fan, but not its efficiency datum. Moreover, the application of the method is not straightforward for fan designs with flow separation at the blade root or immediately downstream of the rotor exit. Also, it is found that the new low-order CFD approach offers potentialities as a tool for the support of the preliminary fan design and deserves future investigations.

Presenting Author: Massimo Masi University of Padova

Presenting Author Biography: Massimo Masi is a mechanical engineer. He is associate professor in Internal Combustion Engine Design and Turbomachines at the University of Padova. He received the Ph.D in Energetics in 1999. His main research interest in the field of low-speed turbomachines is the aerodynamic design of industrial fans.

Authors:

Massimo Masi University of Padova
Piero Danieli University of Padova