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.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

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


    Additional title:

    Sae Technical Papers


    Contributors:

    Conference:

    SAE 2014 International Powertrain, Fuels & Lubricants Meeting ; 2014



    Publication date :

    2014-10-13




    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English




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

    Sundstrom, E. / Semlitsch, B. / Mihaescu, M. et al. | British Library Conference Proceedings | 2014


    Comparative Study on Steady and Unsteady Flow in a Centrifugal Compressor Stage

    Changhee Kim / Changmin Son | DOAJ | 2019

    Free access



    BiGlobal Stability Analysis of Unsteady Flow in Vaneless Diffuser of Centrifugal Compressor

    Hu, Chenxing / Liu, Pengyin / Zhu, Xiaocheng et al. | AIAA | 2017