Browse Publications Technical Papers 2014-01-2856

Assessment of the 3D Flow in a Centrifugal compressor using Steady-State and Unsteady Flow Solvers 2014-01-2856

Numerical analysis methods are used to investigate the flow in a ported-shroud centrifugal compressor under different operating conditions, i.e. several mass flow rates at two different speed lines. A production turbocharger compressor is considered, which is widely used in the heavy automotive sector. Flow solutions obtained under steady-state and transient flow assumptions are compared with available experimental data.
The steady-state Reynolds Averaged Navier-Stokes method is used to assess the overall time averaged flow and the global performance parameters. Additionally, the Large Eddy Simulation (LES) approach is employed to capture the transient flow features and the developed flow instabilities at low mass flow rates near the surge line.
The aim of this study is to provide new insights on the flow instability phenomena in the compressor flow near surge. Comparison of flow solutions obtained for near-optimal efficiency and near-surge conditions are carried out. The unsteady features of the flow field are quantified by means of Fourier transformation analysis, Proper Orthogonal Decomposition and Dynamic Mode Decomposition. For a near optimal efficiency set-up the frequency spectra are broad-banded with no distinct instabilities. Close to the surge line, the spectra show a distinct surge cycle frequency, which is due to flow pulsation in the compressor.
The modal flow decomposition elucidates a mode occurring at the surge frequency. The mode explains the oscillating pumping effect occurring during surge. The surface spectra contours reveal the shape of the pressure pulsation during surge and support that a pressure gradient occurs with the oscillating modes found with the modal decomposition.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 16% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:

Correlating the Experiment and Fluid Structure Interaction Results of a Suction Valve Model from a Hermetic Reciprocating Compressor


View Details


Plastic Turbo for Secondary Air Injection


View Details


The Development of Exhaust Surface Temperature Models for 3D CFD Vehicle Thermal Management Simulations Part 1 - General Exhaust Configurations


View Details