Intake Turbulence Generated by a Steady Valve-Cylinder Flow

2002 ◽  
Author(s):  
Gearle Bailey ◽  
John Kuhlman
Keyword(s):  
Laser Doppler Anemometry ◽  
Axisymmetric Flow ◽  
Valve Lift ◽  
Intake Port ◽  
Intake Valve ◽  
Toroidal Vortex ◽  
Velocity Measurements ◽  
Mean Velocity ◽  
Cylinder Flow ◽  
Turbulence Generation

Axial and swirl velocities have been measured for steady axisymmetric flow in a cylinder past a fixed intake valve located on the cylinder centerline, for two different intake port geometries and two valve lifts, in order to study the effects of swirl and valve lift on turbulence generation. Both Laser Doppler Anemometry (LDA) and Constant Temperature Anemometry (CTA) velocity measurements were obtained. The cylinder diameter was 82.6 mm, cylinder height was 114.3 mm, and the centrally located valve had a diameter of 41.9 mm. The LDA mean axial velocity data indicated a conical jet issuing from the valve, and a recirculating toroidal vortex above the valve for each case. Also, for the swirl intake cases, the swirl mean velocity in the toroidal vortex increased linearly with radius. Axial fluctuation velocities were about 1 m/sec away from the conical jet, for both valve lifts and both inlet flow geometries. In the conical jet, axial fluctuation velocities of 2–2.5 m/sec were observed. The swirl fluctuation was consistently lower than the axial fluctuation. The swirl inlet increased the magnitude of the swirl fluctuation in the conical jet.

Valve and In-Cylinder Flow Generated by a Helical Port in a Production Diesel Engine

1987 ◽  
Vol 109 (4) ◽  
pp. 368-375 ◽  
Author(s):  
C. Arcoumanis ◽  
C. Vafidis ◽  
J. H. Whitelaw
Keyword(s):  
Diesel Engine ◽  
Laser Doppler Anemometry ◽  
Operating Conditions ◽  
Valve Lift ◽  
Valve Closure ◽  
Rapid Decay ◽  
Inlet Valve ◽  
Compression Stroke ◽  
Axial Velocity Distribution ◽  
Cylinder Flow

The flow generated by the helical port of a production Diesel engine has been investigated by laser Doppler anemometry under steady flow and operating conditions at ∼ 900 rpm and compression ratio of 8. The flow around the valve periphery was found to be non-uniform with the axial velocity distribution being more sensitive to valve lift. The in-cylinder swirl distribution at inlet valve closure exhibited an axial stratification in the disc-chamber while turbulence intensity remained constant in the clearance volume during the rest of the compression stroke with levels of 0.5 vp and a minimum of about 0.4 vp at top-dead-center following a rapid decay at θ=340°.

Axisymmetric Flow in a Motored Reciprocating Engine

1978 ◽  
Vol 192 (1) ◽  
pp. 213-223 ◽  
Author(s):  
A. D. Gosman ◽  
A. Melling ◽  
J. H. Whitelaw ◽  
P. Watkins
Keyword(s):  
Laser Doppler Anemometry ◽  
Axisymmetric Flow ◽  
Flow Characteristics ◽  
Small Scale ◽  
Mean Velocity ◽  
Inlet Velocity ◽  
Reciprocating Engine ◽  
Laminar And Turbulent Flow ◽  
Flow Through ◽  
The Mean

A study was made of axisymmetric, laminar and turbulent flow in a motored reciprocating engine with flow through a cylinder head port. Measurements were obtained by laser-Doppler anemometry and predictions for the laminar case were generated by finite-difference means. Agreement between calculated and measured results is good for the main features of the flow field, but significant small scale differences exist, due partly to uncertainties in the inlet velocity distribution. The measurements show, for example, that the mean velocity field is influenced more strongly by the engine geometry than by the speed. In general, the results confirm that the calculation method can be used to represent the flow characteristics of motored reciprocating engines without compression and suggest that extensions to include compression and combustion are within reach.

Intake Valve Lift Strategies for Turbulence Generation

MTZ worldwide ◽  
2013 ◽  
Vol 74 (7-8) ◽  
pp. 42-47 ◽  
Author(s):  
Michael Riess ◽  
Andreas Benz ◽  
Marcus Wöbke ◽  
Marc Sens
Keyword(s):  
Valve Lift ◽  
Intake Valve ◽  
Turbulence Generation

Effects of Intake Port Design and Valve Lift on In-Cylinder Flow and Burnrate

1987 ◽  
Author(s):  
J. C. Kent ◽  
M. Haghgooie ◽  
A. Mikulec ◽  
G. C. Davis ◽  
R. J. Tabaczynski
Keyword(s):  
Valve Lift ◽  
Intake Port ◽  
Port Design ◽  
Cylinder Flow

Intake Valve and In-Cylinder Flow Development in a Reciprocating Model Engine

1986 ◽  
Vol 200 (2) ◽  
pp. 143-152 ◽  
Author(s):  
C Vafidis ◽  
J H Whitelaw
Keyword(s):  
Flow Field ◽  
Laser Doppler Anemometry ◽  
Axial Flow ◽  
Normal Stresses ◽  
Intake Valve ◽  
Inlet Valve ◽  
Piston Bowl ◽  
Flow Development ◽  
Model Engine ◽  
Cylinder Flow

Measurements of three velocity components have been obtained by laser Doppler anemometry at the exit plane of the intake valve and inside the cylinder of a model engine motored at 200 r/min with a compression ratio of 7.7 and both axisymmetric and off-centre valves with flat and bowl-in-piston configurations. The results indicate that during early intake the valve flow is influenced by piston geometry and its proximity to the cylinder head. With the flat piston the TDC flow field is influenced by the intake-generated axial flow pattern but not by the tangential motion, induced by the off-centre valve, which decays around inlet valve closure. The breakdown of the intake-generated vortices is accompanied by redistribution of the normal stresses which, during compression, tend towards homogeneity. Inside the piston bowl, a vortex is induced during early intake and decays later in the induction stroke to a uniform flow field which is transformed during late compression by the squish effect.

scholarly journals A Numerical Study on the In-cylinder Flow and Fuel Distribution with the Change of Intake Valve Lift in a GDI Engine

2013 ◽  
Vol 18 (2) ◽  
pp. 100-105
Author(s):  
K.B. Kim ◽  
M.J. Song ◽  
K.S. Kim ◽  
S.H. Kang ◽  
Y.H. Lee ◽  
...  
Keyword(s):  
Numerical Study ◽  
Valve Lift ◽  
Intake Valve ◽  
Fuel Distribution ◽  
Gdi Engine ◽  
Cylinder Flow

Asymmetrical Flow Behaviour in Transitional Pipe Flow of Non-Newtonian Liquids

2005 ◽  
Author(s):  
R. J. Poole ◽  
M. P. Escudier ◽  
F. Presti ◽  
C. Dales ◽  
C. Nouar ◽  
...  
Keyword(s):  
Turbulent Flow ◽  
Pipe Flow ◽  
Laser Doppler Anemometry ◽  
Fluid Dynamic ◽  
Axisymmetric Flow ◽  
Shear Thinning ◽  
Mean Velocity ◽  
Developed Turbulence ◽  
Wide Range ◽  
Laminar And Turbulent Flow

The purpose of this presentation is to report mean velocity-profile data for fully-developed pipe flow of a wide range of shear-thinning liquids together with two Newtonian control liquids. Although most of the data reported are for the laminar-turbulent transition regime, data are also included for laminar and turbulent flow. The experimental data were obtained in unrelated research programmes in UK, France and Australia, all using laser Doppler anemometry (LDA) as the measurement technique. In the majority of cases, axisymmetric flow is observed for the laminar and turbulent flow conditions, although asymmetry due to the Earth’s rotation is evident for the laminar flow of a Newtonian fluid of low viscosity (i.e. low Ekman number). The key point, however, is that for certain fluids, both yield-stress and viscoelastic (all fluids in this study are shear thinning), asymmetry to varying degrees is apparent at all stages of transition from laminar to turbulent flow, i.e. from the first indications to almost fully-developed turbulence. The fact that symmetrical velocity profiles are obtained for both laminar and turbulent flow of all the non-Newtonian fluids in all three laboratories leads to the conclusion that the asymmetry must be a consequence of a fluid-dynamic mechanism, as yet not identified, rather than imperfections in the flow facilities.

Squish and Swirl-Squish Interaction in Motored Model Engines

1983 ◽  
Vol 105 (1) ◽  
pp. 105-112 ◽  
Author(s):  
C. Arcoumanis ◽  
A. F. Bicen ◽  
J. H. Whitelaw
Keyword(s):  
Laser Doppler Anemometry ◽  
Axial Flow ◽  
Turbulent Energy ◽  
Toroidal Vortex ◽  
Complex Flow ◽  
Ic Engine ◽  
Solid Body Rotation ◽  
Piston Bowl ◽  
Flow Configurations ◽  
Turbulence Generation

Measurements of the three components of velocity and their corresponding fluctuations have been obtained by laser-Doppler anemometry mainly near TDC of compression in a model IC engine motored at 200 rpm with compression ratio of 6.7. The flow configurations comprised an axisymmetric cylinder head with and without upstream induced swirl and each of a flat piston and two centrally located, cylindrical and re-entrant, bowl-in-piston arrangements. In the absence of swirl and squish, the intake-generated mean motion and turbulence decayed considerably by the end of compression. The two piston-bowl configurations, however, resulted in a compression-induced squish motion with consequent formation of a toroidal vortex occupying the whole bowl space. Interacton of swirl, carried from intake and persisting through compression, with squish generated near TDC profoundly altered the axial flow structure. In the case of the cylindrical bowl, the sense of the vortex was reversed by swirl and, in the reentrant bowl, increased the number of vortices to two. The swirling motion inside the cylindrical bowl was close to solid body rotation while the re-entrant bowl gave rise to more complex flow patterns. Squish, in the presence or absence of swirl, did not augment the turbulent energy inside the cylindrical bowl contrary to the reentrant configuration where turbulence generation was observed.

Effect of intake swirl on combustion performance in an unthrottled spark ignition engine

2018 ◽  
Vol 233 (5) ◽  
pp. 1269-1279
Author(s):  
Kaiyu Zhang ◽  
Yingjie Chang ◽  
Zongfa Xie ◽  
Tingting Sun ◽  
Fei Chen
Keyword(s):  
Combustion Rate ◽  
Fuel Injection ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Valve Lift ◽  
Intake Port ◽  
Intake Valve ◽  
Port Fuel Injection ◽  
Air Mixing ◽  
Intake Swirl

A Fully Hydraulic Variable Valve System is described in this article which can achieve continuous variation in valve lift, duration, and timing. The system was installed in a four-cylinder port fuel injection spark ignition engine and achieved unthrottled load control through early intake valve closing. The in-cylinder pressure measured experimentally showed that pumping losses of the unthrottled spark ignition engine at 2000 r/min and 0.189 MPa brake mean effective pressure was reduced by 85.4% compared with the throttled spark ignition engine. However, its slow and unstable combustion reduced the indicated thermal efficiency. Compared with the throttled spark ignition engine, the amount of residual exhaust flowing back into the intake port was greatly reduced at the early stage of the intake process. Consequently, it negatively influenced fuel evaporation and fuel–air mixing processes in the intake port of the port fuel injection spark ignition engine and decreased the flow of in-cylinder gases, which resulted in a low combustion rate. A new centrosymmetric helical valve is proposed in this article to improve the fuel–air mixing and combustion rate of the unthrottled spark ignition engine. The experiments demonstrate that the helical valve can generate a strong intake swirl at small intake valve lift. It helps to increase combustion rate and lower cycle-to-cycle variation, which improves indicated thermal efficiency and fuel economy of the unthrottled spark ignition engine at low load.

Influence of Intake Valve Lift on Flow Capacity of Intake Port

2019 ◽  
Author(s):  
Yang Xu ◽  
Fushui Liu ◽  
Jingmin Rui ◽  
Yang Hua ◽  
Yikai Li
Keyword(s):  
Valve Lift ◽  
Intake Port ◽  
Intake Valve ◽  
Flow Capacity
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