Application of PIV Measurements and Snapshot POD Analysis in a Cylinder Head of Diesel Engine

2017 ◽  
Author(s):  
Zhenyang Zhang ◽  
Hongwei Ma ◽  
Chao Jin ◽  
Cheng Xue ◽  
Yunlong Huang
Keyword(s):  
Diesel Engine ◽  
Flow Field ◽  
Total Energy ◽  
Cylinder Head ◽  
Flow Fields ◽  
Coolant Flow ◽  
Flow Structures ◽  
Fuel Injector ◽  
Piv Measurements ◽  
Water Jacket

The characteristic of coolant flow field in the water jacket of a cylinder head plays an important role in heat exchange, which could even influence the diesel engine’s performance and service life. Measurements and analysis methods to coolant flow field are limited by the complex internal geometrical structure of the cylinder head. In this paper, flow fields in a small and complicated spatial structure are measured by particle image velocimetry (PIV) system and the data are analyzed using proper orthogonal decomposition (POD) method. Time varying coolant flow structures located among two valve seats, a fuel injector seat and a side wall in a real cylinder head are measured by a two dimensional PIV system. PIV results of three measuring planes are displayed in different ways to show flow structures in the water jacket. Distinctive areas can be recognized easily in distributions of different flow parameters. A snapshot POD method is employed to analyze PIV data. Flow structures, which contain different amount of energy, are decomposed into different modes by POD method. POD Mode 1 and ensemble mean flow field are compared together and the relevance index shows a relatively high similarity between these two flow fields. The results also indicate a significant convergence of energy distribution. Energy contained in Mode 1 varies from 22% to 61% of the total energy in different measuring planes. 90% of the total energy is captured in top 10% of the total modes which belong to low-order modes. Energy in high-order modes, which occupy more than 60% of the total modes, contains less than 1% of the total energy. In summary, this paper presents the application of PIV measurements to coolant flow field in a real cylinder head and data processing using a snapshot POD method to analyze PIV results. A set of comprehensive properties showing the spatial and temporal characteristics of coolant flow structure is discussed and concluded detailedly. The data obtained can be used to build an experimental database to optimize coolant flow field structures and verify CFD numerical simulations in order to promote coolant flow passage design and simulation credibility of the diesel engine cooling system.

PIV measurements of coolant flow field in a diesel engine cylinder head

2015 ◽  
Vol 24 (2) ◽  
pp. 179-184
Author(s):  
Hongwei Ma ◽  
Zhenyang Zhang ◽  
Cheng Xue ◽  
Yunlong Huang
Keyword(s):  
Diesel Engine ◽  
Flow Field ◽  
Cylinder Head ◽  
Coolant Flow ◽  
Piv Measurements ◽  
Engine Cylinder

scholarly journals Numerical Simulation of Flow Field Characteristics of The Cooling Water Jacket of A Marine Diesel Engine

2021 ◽  
Vol 261 ◽  
pp. 02040
Author(s):  
Bo Zhang ◽  
Ping Zhang ◽  
Zhao Zhang ◽  
Shaobo Yang ◽  
Chengli Wang ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Flow Field ◽  
Cylinder Head ◽  
Cooling Water ◽  
Cylinder Block ◽  
Marine Diesel Engine ◽  
Water Jacket ◽  
Water Flows ◽  
Marine Diesel ◽  
Flow Field Characteristics

In order to evaluate the flow field characteristics of a marine diesel engine cooling water jacket, and provide a theoretical basis for further optimizing the water jacket structure. A computational fluid dynamics (CFD) method was used to calculate the three-dimensional flow field of the water jacket. Based on the CFD simulation model of the engine water jacket, the analysis of pressure field, velocity field, streamline distribution and flow uniformity of water jacket of diesel engine under rated condition were carried out. The results show that: the total pressure loss of water jacket is 30.3 kPa, in which the pressure loss of cylinder block is 8.4 kPa, and the one of cylinder head and outlet manifold is 21.9 kPa, which indicates that the flow resistance design of the cylinder block and head is reasonable; the flow rate of coolant in the nose zone of cylinder head is above 1.5 m/s, which meets the cooling demand of cylinder head; the cooling water flows circumferentially in the engine block water jacket, and the flow dead zones are easily formed by the mutual extrusion and collision of the water flows; the outlet of the cylinder head water jacket is connected with the outlet manifold at right angle, which leads to large energy loss of the flow field; the maximum non-uniformity of flow rate of water jacket of each cylinder is 5.85%, which can be further optimized by adjusting the position of water jacket inlet.

The Impact of Compressor Exit Conditions on Fuel Injector Flows

2012 ◽  
Vol 134 (11) ◽  
Author(s):  
C. L. Ford ◽  
J. F. Carrotte ◽  
A. D. Walker
Keyword(s):  
Flow Field ◽  
Large Scale ◽  
Numerical Data ◽  
Flow Fields ◽  
Main Reaction ◽  
Fuel Injector ◽  
Lean Burn ◽  
Field Development ◽  
Inlet Conditions ◽  
The Impact

This paper examines the effect of compressor generated inlet conditions on the air flow uniformity through lean burn fuel injectors. Any resulting nonuniformity in the injector flow field can impact on local fuel air ratios and hence emissions performance. The geometry considered is typical of the lean burn systems currently being proposed for future, low emission aero engines. Initially, Reynolds-averaged Navier-Stokes (RANS) computational fluid dynamics (CFD) predictions were used to examine the flow field development between compressor exit and the inlet to the fuel injector. This enabled the main flow field features in this region to be characterized along with identification of the various stream-tubes captured by the fuel injector passages. The predictions indicate the resulting flow fields entering the injector passages are not uniform. This is particularly evident in the annular passages furthest away from the injector centerline which pass the majority of the flow which subsequently forms the main reaction zone within the flame tube. Detailed experimental measurements were also undertaken on a fully annular facility incorporating an axial compressor and lean burn combustion system. The measurements were obtained at near atmospheric pressure/temperatures and under nonreacting conditions. Time-resolved and time-averaged data were obtained at various locations and included measurements of the flow field issuing from the various fuel injector passages. In this way any nonuniformity in these flow fields could be quantified. In conjunction with the numerical data, the sources of nonuniformities in the injector exit plane were identified. For example, a large scale bulk variation (+/−10%) of the injector flow field was attributed to the development of the flow field upstream of the injector, compared with localized variations (+/−5%) that were generated by the injector swirl vane wakes. Using this data the potential effects on fuel injector emissions performance can be assessed.

Study of the steady flow produced by direct injection diesel engine intake ports

2001 ◽  
Vol 215 (2) ◽  
pp. 285-298 ◽  
Author(s):  
J M Desantes ◽  
J V Pastor ◽  
A Doudou
Keyword(s):  
Spectral Analysis ◽  
Diesel Engine ◽  
Flow Field ◽  
Steady Flow ◽  
Cylinder Head ◽  
Laser Doppler Anemometry ◽  
Direct Injection ◽  
Valve Lift ◽  
Turbulent Structures ◽  
Direct Injection Diesel Engine

In this paper laser Doppler anemometry is used to characterize the steady flow field inside the cylinder generated by the two intake ports of a four-valve diesel head over the whole valve lift range and to compare the patterns at two different sections commonly used for global characterization in order to decide which is more appropriate for cylinder head evaluation. A more detailed investigation is performed for two valve lifts where the change in the flow patterns is more evident by applying a spectral analysis with the local normalized slotting technique to study the turbulent structures accompanying the in-cylinder swirl development.

Systematic Multi-Index Validations of SIDI Engine Flow Field LES Computations Using Crank Angle-Resolved PIV Measurements

2019 ◽  
Author(s):  
Mengqi Liu ◽  
Fengnian Zhao ◽  
Xuesong Li ◽  
Min Xu ◽  
Zongyu Yue ◽  
...  
Keyword(s):  
Flow Field ◽  
Flow Fields ◽  
Model Verification ◽  
Piv Measurements ◽  
Multi Index ◽  
Global Indices ◽  
Comparison Results ◽  
Crank Angle ◽  
Flow Field Characteristics ◽  
Cylinder Flow

Abstract In-cylinder flow fields make significant impacts on the fuel atomization, fuel mixture formation, and combustion process in spark ignition direct injection (SIDI) engines. In recent years, model-based simulation approaches are preferred in regard to investigating the transient in-cylinder flow field characteristics. Most commonly, the simulation models are validated using single representative flow field at a typical crank angle measured by particle image velocimetry (PIV). However, it provides only limited knowledge about the flow field which is highly three-dimensional and of transient nature. In this study, crank angle-resolved PIV measurements are conducted on three distinct planes inside the cylinder to capture the transient process of flow field characteristics which vary with the crank angle. These three planes consist of one tumble plane through the spark plug tip, one tumble plane along two intake ports, and one swirl plane at 30 mm below the cylinder head. Large eddy simulation (LES) is employed for the numerical computations using the CONVERGE codes. On the basis of large datasets for both temporal and spatial domains, a multi-index systematic validation approach is conducted. Crank angle-resolved calculations of global indices and local indices are implemented using the flow fields velocity data obtained from both PIV and LES on select planes. Global indices reveal the trends in similarities of different crank angle degrees and locations, while local indices give the detail comparison results. In summary, with the systematic multi-index validation approach, the crucial crank angle degrees and locations for model verification will be detected. Furthermore, the corresponding critical flow features are analyzed. Practical guideline of flow field validation is proposed.

The Impact of Compressor Exit Conditions on Fuel Injector Flows

2012 ◽  
Author(s):  
C. L. Ford ◽  
J. F. Carrotte ◽  
A. D. Walker
Keyword(s):  
Flow Field ◽  
Large Scale ◽  
Numerical Data ◽  
Flow Fields ◽  
Main Reaction ◽  
Fuel Injector ◽  
Lean Burn ◽  
Field Development ◽  
Inlet Conditions ◽  
The Impact

This paper examines the effect of compressor generated inlet conditions on the air flow uniformity through lean burn fuel injectors. Any resulting non-uniformity in the injector flow field can impact on local fuel air ratios and hence emissions performance. The geometry considered is typical of the lean burn systems currently being proposed for future, low emission aero engines. Initially, RANS CFD predictions were used to examine the flow field development between compressor exit and the inlet to the fuel injector. This enabled the main flow field features in this region to be characterized along with identification of the various stream-tubes captured by the fuel injector passages. The predictions indicate the resulting flow fields entering the injector passages are not uniform. This is particularly evident in the annular passages furthest away from the injector center-line which pass the majority of the flow which subsequently forms the main reaction zone within the flame tube. Detailed experimental measurements were also undertaken on a fully annular facility incorporating an axial compressor and lean burn combustion system. The measurements were obtained at near atmospheric pressure/temperatures and under non-reacting conditions. Time-resolved and time-averaged data were obtained at various locations and included measurements of the flow field issuing from the various fuel injector passages. In this way any non-uniformity in these flow fields could be quantified. In conjunction with the numerical data, the sources of non-uniformities in the injector exit plane were identified. For example, a large scale bulk variation (+/−10%) of the injector flow field was attributed to the development of the flow field upstream of the injector, compared with localized variations (+/−5%) that were generated by the injector swirl vane wakes. Using this data the potential effects on fuel injector emissions performance can be assessed.

The Research of Structural Optimization on Diesel Engine Injection Nozzle

2010 ◽  
Vol 97-101 ◽  
pp. 2571-2575
Author(s):  
Ming Hai Li ◽  
Hong Jiang Cui ◽  
Yun Dong Han ◽  
Ang Li
Keyword(s):  
Diesel Engine ◽  
Flow Field ◽  
Numerical Models ◽  
Three Dimensional ◽  
Injection Pressure ◽  
Injection System ◽  
Flow Structures ◽  
Spray Nozzle ◽  
Cad Cam ◽  
Flow Turbulence

In order to improve the performance of 16 V280 diesel engine, the three-dimensional numerical models of the flow field in the nozzle which belongs to the injection system was built, and different detailed flow structures was captured under different pressure conditions. Through the analysis of the flow field, the unsuitable position of the nozzle was located, and the methods which combine CAD / CAM / CFD was applicated to optimize the structure of the nozzle. The analysis results indicate that with the increase of the injection pressure; the flow turbulence intensity increases; the more energy get lost, which was caused by turbulence; the coefficient of flow decreases. After the spray nozzle structure was changed into sphere pin valve, the mass flux under the same level of injection pressure was improved greatly.

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.

Investigation of the Flow Field in a HP Turbine Stage for Two Stator-Rotor Axial Gaps: Part I — 3D Time-Averaged Flow Field

2006 ◽  
Author(s):  
P. Gaetani ◽  
G. Persico ◽  
V. Dossena ◽  
C. Osnaghi
Keyword(s):  
Flow Field ◽  
Steady Flow ◽  
Flow Fields ◽  
Secondary Flows ◽  
Point Of View ◽  
Flow Structures ◽  
Axial Distance ◽  
Turbine Stage ◽  
Subsonic Regime ◽  
Definition Of

An extensive experimental analysis on the subject of unsteady flow field in high pressure turbine stages was carried out at the Laboratorio di Fluidodinamica delle Macchine (LFM) of Politecnico di Milano. The research stage represents a typical modern HP gas turbine stage designed by means of 3D techniques, characterised by a leaned stator and a bowed rotor and operating in high subsonic regime. The first part of the program concerns the analysis of the steady flow field in the stator-rotor axial gap by means of a conventional five-hole probe and a temperature sensor. Measurements were carried out on eight planes located at different axial positions allowing the complete definition of steady flow field both in absolute and relative frame of reference. The evolution of the main flow structures, such as secondary flows and vane wakes, downstream of the stator are here presented and discussed in order to evidence the stator aerodynamic performance and, in particular, the different flow field approaching the rotor blade row for the two axial gaps. This results set will support the discussion of the unsteady stator-rotor effects presented in paper Part II. Furthermore, 3D time-averaged measurements downstream of the rotor were carried out at one axial distance and for two stator-rotor axial gaps. The position of the probe with respect to the stator blades is changed by means of rotating the stator in circumferential direction, in order to describe possible effects of the non-uniformity of the stator exit flow field downstream of the stage. Both flow fields, measured for the nominal and for a very large stator-rotor axial gap, are discussed and results show the persistence of some stator flow structures downstream of the rotor, in particular for the minimum axial gap. Eventually the flow fields are compared to evidence the effect of the stator-rotor axial gap on the stage performance from a time-averaged point of view.

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