Circumferential Variation of Noise at the Blade-Pass Frequency in a Turbocharger Compressor with Ported Shroud

2021 ◽  
Author(s):  
Pranav Sriganesh ◽  
Rick Dehner ◽  
Ahmet Selamet ◽  
Keith Miazgowicz
Keyword(s):  
Ported Shroud

Dynamic Features and their Propagation in a Centrifugal Compressor Housing with Ported Shroud

2012 ◽  
Author(s):  
Matthieu Gancedo ◽  
Erwann Guillou ◽  
Ephraim Gutmark ◽  
Ashraf Mohamed
Keyword(s):  
Centrifugal Compressor ◽  
Dynamic Features ◽  
Ported Shroud

Redesign of a Compressor Stage for a High-Performance Electric Supercharger in a Heavily Downsized Engine

2017 ◽  
Vol 140 (4) ◽  
Author(s):  
Peng Wang ◽  
Mehrdad Zangeneh ◽  
Bryn Richards ◽  
Kevin Gray ◽  
James Tran ◽  
...  
Keyword(s):  
Design Method ◽  
Pressure Ratio ◽  
Compressor Stage ◽  
Impeller Blade ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
Surge Margin ◽  
Stable Operating ◽  
Inverse Design Method ◽  
Ported Shroud

Engine downsizing is a modern solution for the reduction of CO2 emissions from internal combustion engines. This technology has been gaining increasing attention from industry. In order to enable a downsized engine to operate properly at low speed conditions, it is essential to have a compressor stage with very good surge margin. The ported shroud, also known as the casing treatment, is a conventional way used in turbochargers to widen the working range. However, the ported shroud works effectively only at pressure ratios higher than 3:1. At lower pressure ratio, its advantages for surge margin enhancements are very limited. The variable inlet guide vanes are also a solution to this problem. By adjusting the setting angles of variable inlet guide vanes, it is possible to shift the compressor map toward the smaller flow rates. However, this would also undermine the stage efficiency, require extra space for installing the inlet guide vanes, and add costs. The best solution is therefore to improve the design of impeller blade itself to attain high aerodynamic performances and wide operating ranges. This paper reports a recent study of using inverse design method for the redesign of a centrifugal compressor stage used in an electric supercharger, including the impeller blade and volute. The main requirements were to substantially increase the stable operating range of the compressor in order to meet the demands of the downsized engine. The three-dimensional (3D) inverse design method was used to optimize the impeller geometry and achieve higher efficiency and stable operating range. The predicted performance map shows great advantages when compared with the existing design. To validate the computational fluid dynamics (CFD) results, this new compressor stage has also been prototyped and tested. It will be shown that the CFD predictions have very good agreement with experiments and the redesigned compressor stage has improved the pressure ratio, aerodynamic efficiency, choke, and surge margins considerably.

Ported Shroud Flow Processes and Their Effect on Turbocharger Compressor Operation

2017 ◽  
Author(s):  
Sidharath Sharma ◽  
Martyn L. Jupp ◽  
Ambrose K. Nickson ◽  
John M. Allport
Keyword(s):  
Entropy Generation ◽  
Primary Source ◽  
Navier Stokes ◽  
Stable Operation ◽  
Casing Treatment ◽  
Flow Processes ◽  
Compressor Inlet ◽  
Flow Mechanisms ◽  
Sst Turbulence Model ◽  
Ported Shroud

The ported shroud (PS) self-recirculating casing treatment is widely used to delay the onset of the surge by enhancing the aerodynamic stability of the turbocharger compressor. The increase in the stable operation region of the turbocharger compressor is achieved by recirculating the low momentum fluid that blocks the blade passage to the compressor inlet through a ported shroud cavity. While the ported shroud design delays surge, it comes with a small penalty in efficiency. This work presents an investigation of the flow processes associated with a ported shroud compressor and quantifies the effect of these flow mechanisms on the compressor operation. The full compressor stage is numerically modelled using a Reynolds Averaged Navier-Stokes (RANS) approach employing the shear stress transport (SST) turbulence model for steady state simulations at the design and near surge conditions. The wheel rotation is modelled using a multiple reference frame (MRF) approach. The results show that the flow exits the PS cavity at the near surge condition in the form of three jet-like structures of varying velocity amplitudes. Net entropy generation in the compressor model is used to assess the influence of the ported shroud design on the compressor losses, and the results indicate a small Inlet-PS mixing region is the primary source of entropy generation in the near surge conditions. The analysis also explores the trends of entropy generation at the design and the near surge condition across the different speed lines. The results show that the primary source of entropy generation is the impeller region for the design condition and the inlet-PS cavity region for the near surge condition.

Impact of Impeller Casing Treatment on the Acoustics of a Small High Speed Centrifugal Compressor

2018 ◽  
Author(s):  
Sidharath Sharma ◽  
Jorge García-Tíscar ◽  
John M. Allport ◽  
Martyn L. Jupp ◽  
Ambrose K. Nickson
Keyword(s):  
Centrifugal Compressor ◽  
High Speed ◽  
Pressure Fluctuations ◽  
Operating Conditions ◽  
Aerodynamic Noise ◽  
Noise Sources ◽  
Casing Treatment ◽  
Active Research ◽  
Ported Shroud ◽  
The Impact

Ported shroud casing treatment is widely used to delay the onset of surge and thereby enhancing the aerodynamic stability of a centrifugal compressor by recirculating the low momentum fluid in the blade passage. Performance losses associated with the use of recirculation casing treatment are well established in the literature and this is an area of active research. The other, less researched aspect of the casing treatment is its impact on the acoustics of the compressor. This work investigates the impact of ported shroud casing treatment on the acoustic characteristics of the compressor. The flow in two compressor configurations viz. with and without casing treatment operating at the design operating conditions of an iso-speed line are numerically modelled and validated with experimental data from gas stand measurements. The pressure fluctuations calculated as the flow solution are used to compute the spectral signatures at multiple locations to investigate the acoustic phenomenon associated with each configuration. Propagation of the frequency content through the ducts has been estimated with the aid of method of characteristics to enhance the content coming from the compressor. Expected tonal aerodynamic noise sources such as monopole (buzz-saw tones) and dipole (Blade Pass Frequency) are clearly identified in the acoustic spectra of the two configurations. The comparison of two configurations shows higher overall levels and tonal content in the case of a compressor with ported shroud operating at design conditions due to the presence of ‘mid-tones’.

scholarly journals Numerical Flow Analysis of a Centrifugal Compressor with Ported and without Ported Shroud

2014 ◽  
Author(s):  
Bernhard Semlitsch ◽  
JyothishKumar V ◽  
Mihai Mihaescu ◽  
Laszlo Fuchs ◽  
Ephraim Gutmark ◽  
...  
Keyword(s):  
Centrifugal Compressor ◽  
Flow Analysis ◽  
Ported Shroud ◽  
Numerical Flow Analysis

PIV Measurements of Surge Incipience in a Ported Shroud Compressor

2010 ◽  
Author(s):  
Erwann Guillou ◽  
M Gancedo ◽  
Russell Dimicco ◽  
Ephraim Gutmark ◽  
Ashraf Mohamed
Keyword(s):  
Piv Measurements ◽  
Ported Shroud

Experimental Investigation of Flow Instability in a Turbocharger Ported Shroud Compressor

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
Erwann Guillou ◽  
Matthieu Gancedo ◽  
Ephraim Gutmark
Keyword(s):  
Flow Instability ◽  
Dynamic Pressure ◽  
Stability Control ◽  
Stereoscopic Particle Image Velocimetry ◽  
Dimensional Structure ◽  
Structure Evolution ◽  
Unstable Flow ◽  
Flow Recirculation ◽  
Ported Shroud ◽  
The Impact

Turbocharger centrifugal compressors are equipped with a “ported shroud” to reduce flow instabilities at low mass flow rates. This passive stability control device using flow recirculation has been demonstrated to extend the surge margin of a compressor without substantially sacrificing performance. However, the actual working mechanisms of the system are not well understood. In this paper, the relationship between inlet flow recirculation and instability control is studied using stereoscopic particle image velocimetry (PIV) in conjunction with dynamic pressure transducers at the inlet of the turbocharger compressor with and without ported shroud. Both stable and unstable operational points are analyzed using phase-locked PIV measurements during surge. Detailed description of unstable flow in the centrifugal compressor is presented by reconstructing the complex flow structure evolution in the compressor inlet during surge. Rather than one-dimensional, the surge flow is characterized by a three-dimensional structure of both entering and exiting swirling flows, alternating in magnitude during a self-excited pressure cycle. The correlation between pressure and velocity measurements shows that the development of compressor unsteadiness is concurrent with swirling reversed flow at the impeller tip. The impact of the ported shroud on the inlet velocity flowfield is evidenced by the presence of localized flow recirculation. Stability improvement due to the ported shroud is thus a result of removing swirling backflow from the impeller inducer tip and recirculating it into the impeller inlet to increase the near shroud inlet blade loading and the incidence angle.

Meanline Modeling of Ported Shroud Turbocharger Compressor

2012 ◽  
Author(s):  
Xuwen Qiu ◽  
Eric M. Krivitzky ◽  
Peter Bollweg
Keyword(s):  
Cfd Simulation ◽  
Three Dimensional ◽  
Pressure Rise ◽  
Design Stage ◽  
General Mechanism ◽  
Gasoline Engines ◽  
Design Variables ◽  
Preliminary Design Stage ◽  
Compressor Map ◽  
Ported Shroud

The requirements for higher fuel economy and better diesel and gasoline engines demand a wider range in turbocharger compressor operation. Ported shroud compressor housing is one of the most commonly used techniques for compressor map width enhancement. Although the general mechanism of such a flow feature is well understood, there are no readily available design tools to guide the engineers at the preliminary design stage. Designers have had to rely on three-dimensional (3D) CFD tools to sort out many design variables, but these tools can be prohibitively expensive. This paper explains how to develop a ported shroud compressor model on top of a commercial meanline compressor design program. The model considers some basic parameters, such as bleed location and geometry, which drive the recirculation or bypass flow through the bleed channel. The effects of the secondary flow on the compressor performance, such as pressure rise, efficiency, and stall and choke margins are also analyzed. The model prediction is validated with CFD simulation and test data.

Parametric Study on Ported Shroud Locations and Geometries for a Turbocharger Compressor

2019 ◽  
Author(s):  
Suheab Thamizullah ◽  
Abdul Nassar ◽  
Antonio Davis ◽  
Gaurav Giri ◽  
Leonid Moroz
Keyword(s):  
Centrifugal Compressor ◽  
Combustion Engine ◽  
Engine Performance ◽  
Operating Conditions ◽  
Entire Study ◽  
Operating Condition ◽  
Baseline Design ◽  
Operating Range ◽  
Ported Shroud ◽  
The Impact

Abstract Turbochargers are commonly used in automotive engines to increase the internal combustion engine performance during off-design operating conditions. When used, the widest operating range for the turbocharger is desired, which is limited on the compressor side by the choke condition and the surge phenomenon. The ported shroud technology is used to extend the operable working range of the compressor, by permitting flow disturbances that block the blade passage to escape and stream back through the shroud cavity to the compressor inlet. The impact of this technology, on a speed-line, at near optimal operating condition, near choke operating condition and near surge operating condition is investigated. The ported shroud (PS) self-recirculating casing treatment is widely used to delay the onset of surge by enhancing the aerodynamic stability of the turbocharger compressor. While the ported shroud design delays surge, it usually comes with a small penalty in efficiency. This research involves designing a single-stage centrifugal compressor for the given specifications, considering the application of an automotive turbocharger. The ported shroud was then introduced in the centrifugal compressor. The performance characteristics were obtained, both at the design and at off-design conditions, both with and without the ported shroud. The performance was compared at various off-design operating speed lines. The entire study, from designing the compressor to optimizing the ported shroud configuration, was performed using the commercial AxSTREAM® software platform. Parametric studies were performed to study the effect of ported shroud axial location along the blade axial length on the operating range and performance. The baseline design, without the ported shroud (P0), and the final geometry with it for all PS inlet axial locations (P1 to P5) were analysed using a commercial CFD package and the results were compared with those from the streamline solver.

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