Abstract
It is widely accepted that large swirl angles (>60°) are required to deliver meaningful surge margin extension at the relatively low pressure ratios typical of automotive turbocharger compressors. However, in order to maintain performance towards choke (and hence the rated power point of the engine), the requirement is for delivery of zero pre-swirl. These constraints cannot be met using traditional variable inlet guide vane systems, as whether flat plate or cambered vanes are chosen, significant losses are to be expected at low and high mass flow rates respectively.
Taking the above into account, the primary intention of this study was to develop a device capable of efficiently generating large swirl angles for surge margin extension and compressor efficiency enhancement at low mass flow operating points, without adversely affecting performance at other areas of the compressor map.The chosen concept involved placing an axial fan upstream of a standard automotive turbocharger compressor stage. The fan was designed to act as a variable pre-swirl device, which due to being driven by an electric motor, was capable of operating completely independently of the centrifugal impeller.
The chosen concept was progressed through 1-D and 3-D design phases to understand the feasibility of the system, before committing to hardware manufacture and an extensive experimental test campaign to validate the numerical findings and test the surge margin extension potential of the device.
Taking the above into account, the primary intention of this study was to develop a device capable of efficiently generating large swirl angles for surge margin extension and compressor efficiency enhancement at low mass flow operating points, without adversely affecting performance at other areas of the compressor map.The chosen concept involved placing an axial fan upstream of a standard automotive turbocharger compressor stage. The fan was designed to act as a variable pre-swirl device, which due to being driven by an electric motor, was capable of operating completely independently of the centrifugal impeller.
The chosen concept was progressed through 1-D and 3-D design phases to understand the feasibility of the system, before committing to hardware manufacture and an extensive experimental test campaign to validate the numerical findings and test the surge margin extension potential of the device.
| Original language | English |
|---|---|
| Title of host publication | 14th International Conference on Turbochargers and Turbocharging |
| Subtitle of host publication | Institution of Mechanical Engineers |
| Publisher | CRC Press / Balkema |
| Number of pages | 14 |
| ISBN (Electronic) | 978-1-003-13217-2 |
| ISBN (Print) | 978-0-367-67645-2 |
| DOIs | |
| Publication status | Published - 22 Oct 2020 |