The Pulsating Flow Field in a Mixed Flow Turbocharger Turbine: An Experimental and Computational Study

2005 ◽  
Vol 127 (1) ◽  
pp. 144-155 ◽  
Author(s):  
D. Palfreyman ◽  
R. F. Martinez-Botas
Keyword(s):  
Flow Field ◽  
Computational Study ◽  
Field Measurements ◽  
Pulsating Flow ◽  
Computational Method ◽  
Numerical Code ◽  
Turbine Stage ◽  
Contour Plots ◽  
Opening And Closing ◽  
Exhaust Valves

The turbine stage of an automotive pulse system turbocharger is subjected to an unsteady pulsating flow field due to the rapid opening and closing of the reciprocating engine exhaust valves. This leads to a complex and highly disturbed flow field within the delivery volute and turbine passages, which results in an unusual “hysteresis” type performance characteristic. The aim of this paper is to investigate the flow field within the turbine stage under these representative conditions, using a computational method validated against experimental data. This paper is separated into two sections. The first deals with the validation of the numerical code and modeling approach. A mesh dependency study is undertaken with cell discretization ranging 200,000, 850,000, and 1,750,000 cells, where the accuracy is assessed through comparison with experimental performance and flow field measurements. The second part presents an investigation of the flow field under pulse conditions. Time accurate spectra of turbine performance and flow properties at various locations in the turbine stage are presented, as well as contour plots of velocity within a turbine passage at two critical positions during the pulse period.

The Pulsating Flow Field in a Mixed Flow Turbocharger Turbine: An Experimental and Computational Study

2004 ◽  
Author(s):  
D. Palfreyman ◽  
R. F. Martinez-Botas
Keyword(s):  
Flow Field ◽  
Computational Study ◽  
Field Measurements ◽  
Pulsating Flow ◽  
Computational Method ◽  
Numerical Code ◽  
Turbine Stage ◽  
Contour Plots ◽  
Opening And Closing ◽  
Exhaust Valves

The turbine stage of an automotive pulse system turbocharger is subjected to an unsteady pulsating flow field due to the rapid opening and closing of the reciprocating engine exhaust valves. This leads to a complex and highly disturbed flow field within the delivery volute and turbine passages, which results in an unusual ‘hysteresis’ type performance characteristic. The aim of this paper is to investigate the flow field within the turbine stage under these representative conditions, using a computational method validated against experimental data. This paper is separated into two sections. The first deals with the validation of the numerical code and modeling approach. A mesh dependency study is undertaken with cell discretization ranging 200,000, 850,000 and 1,750,000 cells, where the accuracy is assessed through comparison with experimental performance and flow field measurements. The second part presents an investigation of the flow field under pulse conditions. Time accurate spectra of turbine performance and flow properties at various locations in the turbine stage are presented, as well as contour plots of velocity within a turbine passage at two critical positions during the pulse period.

Detailed Study of Pulsating Flow Performance in a Mixed Flow Turbocharger Turbine

2005 ◽  
Author(s):  
Aaron Costall ◽  
Ricardo F. Martinez-Botas ◽  
Dean Palfreyman
Keyword(s):  
Flow Field ◽  
Combustion Engine ◽  
Flow Direction ◽  
Flow Characteristics ◽  
Pulsating Flow ◽  
Turbine Stage ◽  
Complex Flow ◽  
Pulse Period ◽  
Pulse Profile ◽  
Direction Control

Automotive turbocharger turbines experience a highly unsteady and pulsating flow field due to the abrupt operation of the exhaust valves in a reciprocating internal combustion engine. Previous work has demonstrated and validated against experiment a computational model of a turbine stage under such conditions. The same model is used in the present paper to examine in greater detail the complex flow characteristics observed. The pulsating inlet condition results in a highly disturbed flow field in the turbine stage, the main features of which have already been identified. The effect of the passing of the blades at the volute tongue is observed, and the fluctuating velocity field in the blade passages is seen to lead to poor flow direction control at the turbine inlet and exit. The turbine geometry, calculated for steady flow, is forced to operate away from design conditions for most of the pulse period. Through a detailed analysis of the intricate flow field features at varying instants during the pulse period, this paper highlights areas of the blade geometry and periods in the pulse profile that should be investigated further, such that the integrated performance across the entire pulse cycle can be improved.

Endoscopic 2D particle image velocimetry (PIV) flow field measurements in IC engines

2002 ◽  
Vol 33 (6) ◽  
pp. 794-800 ◽  
Author(s):  
U. Dierksheide ◽  
P. Meyer ◽  
T. Hovestadt ◽  
W. Hentschel
Keyword(s):  
Particle Image Velocimetry ◽  
Flow Field ◽  
Particle Image ◽  
Field Measurements ◽  
Image Velocimetry ◽  
Ic Engines

scholarly journals Transient Three-Dimensional Flow Field Measurements by Means of 3D µPTV in Drying Poly(Vinyl Acetate)-Methanol Thin Films Subject to Short-Scale Marangoni Instabilities

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1223
Author(s):  
Max Tönsmann ◽  
Philip Scharfer ◽  
Wilhelm Schabel
Keyword(s):  
Flow Field ◽  
Vinyl Acetate ◽  
Three Dimensional ◽  
Field Measurements ◽  
Initial Assessment ◽  
Ambient Conditions ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Short Scale ◽  
Dry Film

Convective Marangoni instabilities in drying polymer films may induce surface deformations, which persist in the dry film, deteriorating product performance. While theoretic stability analyses are abundantly available, experimental data are scarce. We report transient three-dimensional flow field measurements in thin poly(vinyl acetate)-methanol films, drying under ambient conditions with several films exhibiting short-scale Marangoni convection cells. An initial assessment of the upper limit of thermal and solutal Marangoni numbers reveals that the solutal effect is likely to be the dominant cause for the observed instabilities.

A fast response miniature probe for wet steam flow field measurements

2016 ◽  
Vol 27 (12) ◽  
pp. 125901
Author(s):  
Ilias Bosdas ◽  
Michel Mansour ◽  
Anestis I Kalfas ◽  
Reza S Abhari
Keyword(s):  
Flow Field ◽  
Field Measurements ◽  
Fast Response ◽  
Steam Flow ◽  
Wet Steam ◽  
Wet Steam Flow
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