In-Cylinder Fuel-Air Mixture Investigation by Particle Image Velocimetry in a GDI Engine

2004 ◽  
Author(s):  
G. Valentino ◽  
M. Auriemma ◽  
G. Caputo ◽  
F. E. Corcione
Keyword(s):  
Particle Image Velocimetry ◽  
Flow Rate ◽  
Particle Image ◽  
Direct Injection ◽  
Air Flow ◽  
Piv Technique ◽  
Fuel Jet ◽  
Image Velocimetry ◽  
Gdi Engine ◽  
Intake Flow

The present paper aims at providing experimental results on the spray structure and its interaction with the air flow generated by the intake ducts of a commercial light duty gasoline direct injection (GDI) engine head. The investigation was carried out by the Particle Image Velocimetry (PIV) technique to investigate the air flow and fuel droplets velocity evolution within a prototype cylinder with optical accesses. Experiments were carried out at various operating conditions reproducing the mixture preparation for an early injection strategy. The PIV technique was applied in a flow test rig assembled with a blower, which supplied the intake flow rate, connected to the intake manifold of a commercial 4-valve direct injection gasoline engine head modified to lay down an external driving control system for the valves motion. Experiments were taken equipping the engine head with a common rail injection system able to work up to 10 MPa, and a swirled type injector having a nozzle diameter of 0.50 mm and a nominal cone angle of 60°. Tests were taken, on a plane crossing the cylinder and the injector axes, supplying to the prototype cylinder an intake flow rate of 29 m3/h and spraying the gasoline at two injection timings in a range of injection pressure of 6, 8, and 10 MPa. The results provided detailed information on the intake flow field behavior and the evolution of fuel jet within the air flow. The intake flow velocity distribution, acquired at different cam angle during the induction, showed the development of an initial clockwise tumble flow with a tendency to produce two large flow structures: a main counter clockwise vortex and a clockwise ones located at the opposite side of the field of view. Images of the interaction of the fuel with the tumble motion displayed, firstly, a fuel jet shape that traveled not affected by the tumble motion because of its high momentum. Later during the intake, the fuel was strongly distorted by the air motion with the formation of clusters detached from the main jet and spread within the cylinder so allowing to hypothesize that the intake bulk flow may be a crucial parameter to control the fuel penetration and the droplets distribution within the cylinder.

Stereoscopic Particle Image Velocimetry Measurements and Proper Orthogonal Decomposition Analysis of the In-Cylinder Flow of Gasoline Direct Injection Engine

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Mohammed El-Adawy ◽  
M. R. Heikal ◽  
A. Rashid A. Aziz
Keyword(s):  
Particle Image Velocimetry ◽  
Proper Orthogonal Decomposition ◽  
Particle Image ◽  
Direct Injection ◽  
Orthogonal Decomposition ◽  
Stereoscopic Particle Image Velocimetry ◽  
Gasoline Direct Injection ◽  
Image Velocimetry ◽  
Gdi Engine ◽  
Proper Orthogonal

Intake generated flows are known to have a fundamental influence on the combustion both in spark ignition (SI) and compression ignition engines. This study experimentally investigated the tumble flow structures inside a cylinder of gasoline direct injection (GDI) engine utilizing a stereoscopic time-resolved particle image velocimetry (PIV). The experiments were conducted in a GDI engine head for a number of fixed valve lifts and 150 mmH2O pressure difference across the intake valves. A tumble flow analysis was carried out considering different vertical tumble planes. In addition, the proper orthogonal decomposition (POD) identification technique was applied on the PIV data in order to spatially analyze the structures embedded in the instantaneous velocity data sets. The results showed that the flow was dominated by a strong tumble motion in the middle of cylinder at high valve lifts (8–10 mm). Moreover, it is worth pointing out that, because of the complexity of the flow at the high valve lifts, the flow energy was distributed over a higher number of POD modes. This was confirmed by the need of a higher number of POD modes needed to reconstruct the original velocity field to the same level of fidelity.

scholarly journals Measurement of Air Flow Outside a Burning Cigarette during a Puff using Particle Image Velocimetry

2004 ◽  
Vol 21 (4) ◽  
pp. 216-222
Author(s):  
A Nagao ◽  
K Miura ◽  
S Kitao ◽  
M Horio
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Air Flow ◽  
Maximum Velocity ◽  
Flow Distribution ◽  
Combustion Mechanism ◽  
Air Flow Rate ◽  
Tracer Particles ◽  
Image Velocimetry ◽  
Cigarette Paper

AbstractIn order to clarify the mechanism for the generation of cigarette smoke, the combustion mechanism of a burning cigarette during a puff was investigated by focusing on air transfer. In particular, the air flow distribution outside a burning cigarette was observed and related to the aerodynamic effects of the cigarette paper and the puffing rate. The air flow rate was measured by Particle Image Velocimetry (PIV), using olive oil droplets as the tracer particles. It was found that air does not flow into the tip of the burning cigarette and that the air flow was concentrated at the region -2 to 2 mm around the cigarette paper char-line. This behavior was independent of the cigarette paper basis weight. When the puffing rate was changed from 2.5 to 35 mL/s, the air flow was concentrated at a region close to the cigarette paper char-line and the maximum velocity around the cigarette paper char-line increased with the puffing rate.

scholarly journals Novel analysis for large strains based on particle image velocimetry

2017 ◽  
Vol 54 (7) ◽  
pp. 933-944 ◽  
Author(s):  
Núria M. Pinyol ◽  
Mauricio Alvarado
Keyword(s):  
Particle Image Velocimetry ◽  
Slope Failure ◽  
Particle Image ◽  
Large Strains ◽  
Software Packages ◽  
Piv Technique ◽  
Standard Procedures ◽  
Image Velocimetry ◽  
Sandy Slope ◽  
Piv Analysis

Over the last few decades, the particle image velocimetry (PIV) technique has become an interesting tool used to measure displacements in the field of experimental mechanics. This paper presents a procedure to interpret PIV displacements, measured following an Eulerian scheme, with the purpose of providing accumulated displacements, velocities, accelerations, and strains on points representing physical particles. Strains are computed as the gradient of displacements. When compared with other standard procedures already published, the presented methodology is especially well suited to interpret large strains. The basis of the procedure is to map displacement increments measured through PIV analysis on the subset (or patch) centres into numerical particles that are defined as portions of the moving masses whose deformation is analyzed. The implementation of the method is explained in detail, highlighting its simplicity. The procedure can be used as a post-processor of currently available PIV software packages. The methodology is first applied to synthetic cases of rectangular samples in which known displacements are imposed and also to a sandy slope failure experiment involving large displacements. The method reproduces satisfactorily the recorded images.

Experimental Investigation of Flow Blurring Atomizer at Near Field Using Particle Image Velocimetry

2019 ◽  
Author(s):  
Raju Murugan ◽  
Dhanalakshmi Sellan ◽  
Pankaj S. Kolhe
Keyword(s):  
Particle Image Velocimetry ◽  
Flow Rate ◽  
Liquid Flow ◽  
Particle Image ◽  
Liquid Flow Rate ◽  
Diagnostic Technique ◽  
Reynolds Stresses ◽  
Full Field ◽  
Image Velocimetry ◽  
Spray Droplets

Abstract Two-fluid flow blurring atomization is characterized by the backflow recirculation of the air phase in the liquid pipe by bifurcation of the liquid and airflow. Most of the primary spray process is completed in the injector due to the penetration of air into the liquid tube. Thus, the majority of the liquid ligaments are converted into a fine spray at the outlet of the nozzle. Experiments were performed with two different air to liquid ratios (0.6 and 1) by mass, where water is considered as the liquid and airflow was kept constant (0.2 g/s). To change the ALR, the liquid flow rate was changed. Particle image velocimetry (PIV) diagnostic technique provides the full-field velocity of the spray droplets (discrete phase). It may be noted that sprays are self-seeded and PIV measurements reflect the droplet velocities instead of air velocity. To understand the effect of the spatial resolution of PIV on spray droplet velocity; experiments were conducted at three different spatial resolutions (11.8, 16.4 and 23.22 μm/pixel) for each ALR. As the ALR is increased, the mass of the liquid in the spray decreases, resulting in finer atomization and velocity of the spray droplets. This means that finer droplets are generated for the same mass of air at a lower liquid flow rate as compared to higher liquid flow rate. Note that Reynolds stresses provide an indication of the turbulent breakup of the droplet and larger magnitudes observed for higher ALR indicate finer atomization.

Effect of inlet port on the flow in the cylinder of an internal combustion engine

2006 ◽  
Vol 220 (1) ◽  
pp. 73-82 ◽  
Author(s):  
A Yasar ◽  
B Sahin ◽  
H Akilli ◽  
K Aydin
Keyword(s):  
Particle Image Velocimetry ◽  
Velocity Distribution ◽  
Particle Image ◽  
Combustion Engine ◽  
Flow Characteristics ◽  
Intake Port ◽  
Intake Valve ◽  
Piv Technique ◽  
Image Velocimetry ◽  
Image Density

In this study, the characteristics of flow emerging from the inlet of the intake port in the cylinder were investigated experimentally. A particle image velocimetry (PIV) technique was used to measure the velocity distribution in order to observe and analyse the flow behaviour. High-image-density PIV provided acquisition of patterns of instantaneous and averaged vorticity and velocity, revealing the detail of the flow characteristics in the cylinder cavity. With this measuring technique, it is possible to study the effect of intake valve geometry on the flow behaviours. The results showed that the flow structure changed substantially along the cylinder stroke due to the geometry of the intake valve port.

Experimental Study of the Characteristics of Gas Impinging Streams Using PIV Technique

2013 ◽  
Author(s):  
Wei Wei ◽  
ZhiYi Li ◽  
Fengxia Liu ◽  
Zhijun Liu
Keyword(s):  
Mass Transfer ◽  
Experimental Study ◽  
Flow Field ◽  
Flow Rate ◽  
Particle Image ◽  
Velocity Fields ◽  
Experimental Equipment ◽  
Piv Technique ◽  
Tracer Particles ◽  
Image Velocimetry

Impinging streams technology has been widely used in many applications in recent years because of its enhancement to the heat and mass transfer between phases. In this paper, in order to investigate the influences of the impinging distance and flow rate on the characters of the flow field, gas-gas impinging streams flow fields are tested experimentally and analyze qualitatively with particle image velocimetry (PIV). The experimental equipment consists of two opposite nozzles which are the same axis. A PIV system is used to measure the characters of the 2-D flow field between two opposite nozzles. The gas is delivered by a compressor through two opposite jets which could be seeded with oil droplets as tracer particles. The effects of the flow rate and impinging distance on the velocity fields of impinging zone are investigated in detail. As the flow rate increases from 0.2 m3/h to 0.8 m3/h, the width of impinging zone increases from 0.25 to 0.5. However, the range of impinging zone does not change significantly as the impinging distance increases from 61mm to 94mm. The results indicate that the PIV technique is an effective method to measure and analyze the characters of impinging streams.

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