An Experimental and Computational Analysis of the Flow Field in a Four-Valve Spark Ignition Engine-Focus on Cycle-Resolved Turbulence

1990 ◽  
Author(s):  
Jean-François Le Coz ◽  
Stéphane Henriot ◽  
Philippe Pinchon
2016 ◽  
Vol 98 (1) ◽  
pp. 237-264 ◽  
Author(s):  
Peter Janas ◽  
Irenäus Wlokas ◽  
Benjamin Böhm ◽  
Andreas Kempf

2019 ◽  
Vol 21 (4) ◽  
pp. 664-682
Author(s):  
Martin Theile ◽  
Martin Reißig ◽  
Egon Hassel ◽  
Dominique Thévenin ◽  
Martin Hofer ◽  
...  

This work summarizes the numerical analysis of the effect of early fuel injection on the charge motion in a direct injection spark ignition engine concerning cyclic fluctuations of the flow field. The combination of the scale-resolving turbulence model “Scale Adaptive Simulation” and post-processing routines for vortex trajectory visualization allows for a detailed insight into the temporal resolved and cycle-dependent behavior of the charge motion. In the first part, a simplified engine set-up is presented and used as a validation case to ensure correct behavior of the turbulence model and post-processing routines. In the second part, the computational fluid dynamics model of the real engine is introduced. The application of the proposed vortex tracking algorithm is shown, and a short discussion about the transient behavior of the charge motion in this engine set-up is given. The third part describes the analysis of the influence of the fuel injection on the charge motion at different engine speeds from 1000 to 3000 r/min and variations of the intake pressure from 1 to 2 bar. Finally, the impact on different flow field properties at possible ignition timings is discussed. Changes in mean flow field quantities as well as in aerodynamic fluctuations are found as a consequence of fuel injection.


Author(s):  
Damian E. Ramajo ◽  
Norberto M. Nigro

Numerical and experimental techniques were applied in order to study the in-cylinder flow field in a commercial four-valve per cylinder spark ignition engine. Investigation was aimed at analyzing the generation and evolution of tumble-vortex structures during the intake and compression strokes, and the capacity of this engine to promote turbulence enhancement during tumble degradation at the end of the compression stroke. For these purposes, three different approaches were analyzed. First, steady flow rig tests were experimentally carried out, and then reproduced by computational fluid dynamics (CFD). Once CFD was assessed, cold dynamic simulations of the full engine cycle were performed for several engine speeds (1500 rpm, 3000 rpm, and 4500 rpm). Steady and cold dynamic results were compared in order to assess the feasibility of the former to quantify the in-cylinder flow. After that, combustion was incorporated by means of a homogeneous heat source, and dynamic boundary conditions were introduced in order to approach real engine conditions. The combustion model estimates the burning rate as a function of some averaged in-cylinder flow variables (temperature, pressure, turbulent intensity, and piston position). Results were employed to characterize the in-cylinder flow field of the engine and to establish similarities and differences between the three performed tests that are currently used to estimate the engine mean flow characteristics (steady flow rig, and cold and real dynamic simulations).


1988 ◽  
Author(s):  
R. Herweg ◽  
Ph. Begleris ◽  
A. Zettlitz ◽  
G.F.W. Ziegler

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