Session: 10-02 Fan and System Optimisation

Paper Number: 154693

Aerodynamics Numerical Optimization and Experimental Verification of a Low Reynolds Number Mixed Flow Blower for Multiple Operational Points 

Small compression systems are widely used in household appliances to move air and its performance has a direct impact on energy consumption and acoustic comfort. The development of high-performance fans and blowers are usually based on designer experience and existing hardware. However, proper design relies on matching the component performance to the application requirements, such as range of operation, system restriction and noise regulations. In addition, products usually have different operational modes which change the restriction of the system and/or the compressor rotational speed.
Modern CAE tools allow to parametrize turbomachinery baseline cases and create automated workflows for Design of Experiments and run optimization algorithms to generate the best candidate for specific criterion. Selecting the right parameters to optimize it is in itself a challenge usually not given the right importance, as not necessarily a design variant with a higher isentropic efficiency (a usual parameter to optimize) translates to a more efficient product which consumes less power and produces less noise, etc.
This paper describes a methodology for using commercially available tools to numerically optimize a compression system and then experimentally verify the validity of the optimization design variants and its performance for an existing system restriction curve. The baseline design case is a blower currently being used in different products - a mixed flow compressor with low Reynolds number. There is an opportunity to improve its performance while respecting the same package envelope – in summary, only the number of blades and blade angle distribution was changed.
Two CFD based Design-of-Experiments and one surrogate based optimization have been run and their best design candidates, for different criteria, were selected, prototyped, and experimentally tested in an aeroacoustics rig.
The optimum design candidates were achieved in a relatively modest number of CFD runs, resulting in a new compressor design which consumes almost 5% less power for a given system restriction for the same overall sizing.

Presenting Author: Thiago Ebel Concepts NREC

Presenting Author Biography: Thiago Ebel is a Customer Success Manager - Innovation and Strategy at Concepts NREC. Previously his role was Associate Principal Aerodynamics Engineer at Dyson Ltd. He earned his degree in Mechanical Engineering from Federal University of Santa Catarina (Brazil) and one year of the degree was completed as Exchange Program at Curtin University (Australia) after being awarded a Scholarship from the Brazilian Government. His thesis was awarded with the 2016 Don Miller Award for Thermo-Fluid Design Excellence. Thiago has authored and co-authored peer-reviewed technical papers and holds 2 patents on aero-acoustic.

Authors:

Thiago Ebel Concepts NREC
William Thoburn Dyson Ltd
Michael Collison Dyson Ltd