ABSTRACT
This paper presents the analysis and results of the implementation non-radial fibre blading radial turbines for waste heat recovery (WHR). WHR technologies, such as turbo-compounding, have to operate at low pressure ratios and low speed conditions, leading to lower centrifugal stress compared to traditional turbocharger turbines. Removing this constraint introduces a new degree of freedom and allows more flexibility in the blade design.
The design methodologies presented in this paper consist of a 3D parametric model coupled with Computational Fluid Dynamic (CFD). The 3D parametric model generated a sampling of about a hundred geometries and predicted the efficiency using single blade passage simulations. The sensitivity analysis showed the effect of each design parameter on efficiency. A radial fibre turbine geometry was optimised for maximum efficiency. The optimum radial fibre geometry was set as the baseline for further non-radial blading optimisation, based on a parametric-CFD approach. The efficiency improvement between the optimum non-radial fibred design and the optimum radial fibre design was found to be +2.0pp experimentally at the Imperial College turbocharger facility.
