Use of Experimentally Measured In-Cylinder Flow Field Data at IVC as Initial Conditions to CFD Simulations of Compression Stroke in I.C. Engines - A Feasibility Study

1994 ◽  
Author(s):  
N. Trigui ◽  
H. Affes ◽  
J. C. Kent
Keyword(s):  
Flow Field ◽  
Feasibility Study ◽  
Field Data ◽  
Initial Conditions ◽  
Cfd Simulations ◽  
Compression Stroke ◽  
Cylinder Flow

Numerical Analysis of Swirl Control Strategies in a Four Valve HSDI Diesel Engine

2004 ◽  
Author(s):  
S. Fontanesi ◽  
E. Mattarelli ◽  
L. Montorsi
Keyword(s):  
Flow Field ◽  
Control Strategies ◽  
Cfd Simulations ◽  
Full Load ◽  
Partial Load ◽  
Swirl Intensity ◽  
Port Design ◽  
Current Production ◽  
Hsdi Diesel Engine ◽  
Cylinder Flow

Recent four value HSDI Diesel engines are able to control the swirl intensity, in order to enhance the in-cylinder flow field at partial load without decreasing breathing capabilities at full load. Making reference to a current production engine, the purpose of this paper is to envestiage the influence of port design and flow-control strategies on both engine permeability and in-cylinder flow field. Using previously validated models, 3-D CFD simulations of the intake and compression strokes are performed in order to predict the in-cylinder flow patterns originated by the different configurations. The comparison between the two configurations in terms of airflow at full load indicates that Geometry 2 can trap 3.03% more air than Geometry 1, while the swirl intensity at IVC is reduced (−30%). The closure of one intake valve (the left one) is very effective to enhance the swirl intensity at partial load: the Swirl Ratio at IVC passes from 0.7 to 2.6 for Geometry 1, while for Geometry 2 it varies from 0.4 to 2.9.

Study of the Impact of Change of Clearance on the Flow Field and Rotordynamic Coefficients for a Smooth, Whirling Annular Seal

2010 ◽  
Author(s):  
Aarthi Sekaran ◽  
G. L. Morrison
Keyword(s):  
Flow Field ◽  
Flow Regime ◽  
Field Data ◽  
3D Model ◽  
Cfd Simulations ◽  
Rotordynamic Coefficients ◽  
Preliminary Model ◽  
Small Clearance ◽  
Annular Seal ◽  
The Impact

The flow field and the rotordynamic coefficients for a smooth, whirling annular seal were investigated by means of a CFD study involving a full 3D model. The preliminary model (of clearance 1.27mm) was validated by comparison to existing experimental flow field data after which CFD simulations were made for a smaller clearance (0.127mm). The flow field changed significantly with the change in clearance and it was seen that the larger clearance showed an inertia dominated flow regime as opposed to the viscous flow regime for the small clearance. Upon the implementation of Childs’ theory for the computation of rotordynamic coefficients, it was observed that forces for the larger clearance did not exhibit the whirl ratio dependence assumed in this theory. The smaller clearance however showed the expected trend with values of the coefficients in the range predicted.

Deep feature learning of in-cylinder flow fields to analyze cycle-to-cycle variations in an SI engine

2020 ◽  
pp. 146808742097414
Author(s):  
Daniel Dreher ◽  
Marius Schmidt ◽  
Cooper Welch ◽  
Sara Ourza ◽  
Samuel Zündorf ◽  
...  
Keyword(s):  
Flow Field ◽  
Engine Performance ◽  
Feature Learning ◽  
Flow Fields ◽  
High Energy ◽  
Flow Structures ◽  
Compression Stroke ◽  
Deep Feature ◽  
Deep Feature Learning ◽  
Cylinder Flow

Machine learning (ML) models based on a large data set of in-cylinder flow fields of an IC engine obtained by high-speed particle image velocimetry allow the identification of relevant flow structures underlying cycle-to-cycle variations of engine performance. To this end, deep feature learning is employed to train ML models that predict cycles of high and low in-cylinder maximum pressure. Deep convolutional autoencoders are self-supervised-trained to encode flow field features in low dimensional latent space. Without the limitations ascribable to manual feature engineering, ML models based on these learned features are able to classify high energy cycles already from the flow field during late intake and the compression stroke as early as 290 crank angle degrees before top dead center ([Formula: see text]) with a mean accuracy above chance level. The prediction accuracy from [Formula: see text] to [Formula: see text] is comparable to baseline ML approaches utilizing an extensive set of engineered features. Relevant flow structures in the compression stroke are revealed by feature analysis of ML models and are interpreted using conditional averaged flow quantities. This analysis unveils the importance of the horizontal velocity component of in-cylinder flows in predicting engine performance. Combining deep learning and conventional flow analysis techniques promises to be a powerful tool for ultimately revealing high-level flow features relevant to the prediction of cycle-to-cycle variations and further engine optimization.

Feasibility study for life event sensor on big field data

2015 ◽  
Author(s):  
Noriyuki Kushiro ◽  
Taichi Ide ◽  
Kazuki Tomonaga ◽  
Yuki Ogawa ◽  
Toshiyasu Higuma
Keyword(s):  
Feasibility Study ◽  
Field Data ◽  
Life Event

Modeling and prediction for the oxidation efficiency of magnesium sulfite in aeration tank of magnesium-based seawater exhaust gas clean system

2017 ◽  
Vol 233 (1) ◽  
pp. 164-173
Author(s):  
Quan Liu ◽  
Yimin Zhu ◽  
Tie Li ◽  
Xiaojia Tang ◽  
Weifeng Liu ◽  
...  
Keyword(s):  
Flow Field ◽  
Initial Conditions ◽  
Negative Impact ◽  
Fluid Model ◽  
Aeration Tank ◽  
Exhaust Gas ◽  
Clean System ◽  
Physics Modeling ◽  
Set Up ◽  
Oxidation Efficiency

In magnesium-based seawater exhaust gas clean system, the desulfurization by-product, magnesium sulfite (MgSO3), has a negative impact on the ecological environment, which needs to be treated to make harmless. Due to the limited space on board, the aeration oxidation method is used to convert it to magnesium sulfate. Because of the variable size, shape and flow field of aeration tank, it is difficult and expensive to design and verify the oxidation efficiency of the aeration tank by experimental method. In this work, in order to predict the oxidation efficiency accurately, RFlow, a computational fluid dynamics software, was used to analyze the flow field and MgSO3 oxidation reaction in aeration tank. The subdomain technology was adopted for physics modeling and mesh generation of the aeration tank, and the total number of meshes was 285,000. The multi-phase flow field model was set up using the multi-fluid model and dispersive k-ε turbulence model. Under the given initial conditions, the predicted oxidation efficiency was 94.2%. Compared with the results of the actual ship test, the prediction model for MgSO3 oxidation efficiency of the aeration tank is reliable.

scholarly journals Effect of Engine Specifications on In-Cylinder Flow Field in a Spark-Ignited Natural Gas Engine

1999 ◽  
Vol 34 (11) ◽  
pp. 764-773
Author(s):  
Yukiyoshi Fukano ◽  
Kazuo Tachibana ◽  
Shigeo Kida ◽  
Toshikazu Kadota
Keyword(s):  
Natural Gas ◽  
Flow Field ◽  
Gas Engine ◽  
Natural Gas Engine ◽  
Cylinder Flow

Investigation of Swirl Ratio Impact on In-Cylinder Flow in a SIDI Optical Engine

2015 ◽  
Author(s):  
Hanyang Zhuang ◽  
David L. S. Hung ◽  
Jie Yang ◽  
Shaoxiong Tian
Keyword(s):  
Flow Field ◽  
Soot Formation ◽  
Flow Characteristics ◽  
Control Valve ◽  
Exhaust Emission ◽  
Swirl Ratio ◽  
Optical Engine ◽  
Crank Angle ◽  
Cylinder Flow ◽  
Intake Swirl

Advanced powertrain technologies have improved engine performance with higher power output, lower exhaust emission, and better controllability. Chief among them is the development of spark-ignition direct-injection (SIDI) engines in which the in-cylinder processes control the air flow motion, fuel-air mixture formation, combustion, and soot formation. Specifically, intake air with strong swirl motion is usually introduced to form a directional in-cylinder flow field. This approach improves the mixing process of air and fuel as well as the propagation of flame. In this study, the effect of intake air swirl on in-cylinder flow characteristics was experimentally investigated. High speed particle image velocimetry (PIV) was conducted in an optical SIDI engine to record the flow field on a swirl plane. The intake air swirl motion was achieved by adjusting the opening of a swirl ratio control valve which was installed in one of the two intake ports in the optical engine. Ten opening angles of the swirl ratio control valve were adjusted to produce an intake swirl ratio from 0.55 to 5.68. The flow structures at the same crank angle degree, but under different swirl ratio, were compared and analyzed using proper orthogonal decomposition (POD). The flow dominant structures and variation structures were interpreted by different POD modes. The first POD mode captured the most dominant flow field structure characteristics; the corresponding mode coefficients showed good linearity with the measured swirl ratio at the compression stroke when the flow was swirling and steady. During the intake stroke, strong intake air motion took place, and the structures and coefficients of the first modes varied along different swirl ratio. These modes captured the flow properties affected by the intake swirl motion. Meanwhile, the second and higher modes captured the variation feature of the flow at various crank angle degrees. In summary, this paper demonstrated a promising approach of using POD to interpret the effectiveness of swirl control valve on in-cylinder swirl flow characteristics, providing better understanding for engine intake system design and optimization.

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