Statistical Approach on Visualizing Multi-Variable Interactions in a Hybrid Breakup Model under ECN Spray Conditions

2017 ◽  
Vol 10 (5) ◽  
pp. 2461-2477 ◽  
Author(s):  
Daniel M. Nsikane ◽  
Kenan Mustafa ◽  
Andrew Ward ◽  
Robert Morgan ◽  
David Mason ◽  
...  
Keyword(s):  
Statistical Approach ◽  
Hybrid Breakup Model ◽  
Breakup Model ◽  
Variable Interactions

scholarly journals Large-eddy spray simulation under direct-injection spark-ignition engine-like conditions with an integrated atomization/breakup model

2020 ◽  
pp. 146808741988186
Author(s):  
Hongjiang Li ◽  
Christopher J Rutland ◽  
Francisco E Hernández Pérez ◽  
Hong G Im
Keyword(s):  
Direct Injection ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Computational Domain ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Hybrid Breakup Model ◽  
Direct Injection Spark Ignition ◽  
Breakup Model ◽  
The Given

In this work, a hybrid breakup model tailored for direct-injection spark-ignition engine sprays is developed and implemented in the OpenFOAM CFD code. The model uses the Lagrangian–Eulerian approach whereby parcels of liquid fuel are injected into the computational domain. Atomization and breakup of the liquid parcels are described by two sub-models based on the breakup mechanisms reported in the literature. Evaluation of the model has been carried out by comparing large-eddy simulation results with experimental measurements under multiple direct-injection spark-ignition engine-like conditions. Spray characteristics including liquid and vapor penetration curves, droplet velocities, and Sauter mean diameter distributions are examined in detail. The model has been found to perform well for the spray conditions considered in this work. Results also show that after the end of injection, most of the residual droplets that are still in the breakup process are driven by the bag and bag–stamen breakup mechanisms. Finally, an effort to unify the breakup length parameter is made, and the given value is tested under various ambient density and temperature conditions. The predicted trends follow the measured data closely for the penetration rates, even though the model is not specifically tuned for individual cases.

NUMERICAL SIMULATION OF HIGH-PRESSURE FUEL SPRAY BY USING A NEW HYBRID BREAKUP MODEL

2017 ◽  
Vol 27 (12) ◽  
pp. 999-1023 ◽  
Author(s):  
Wenliang Qi ◽  
Wenping Zhang ◽  
Pingjian Ming ◽  
Ming Jia ◽  
Ye Peng
Keyword(s):  
Numerical Simulation ◽  
High Pressure ◽  
Fuel Spray ◽  
Hybrid Breakup Model ◽  
Breakup Model

Numerical Investigation of Combustion and Emission With Different Diesel Surrogate Fuel by Hybrid Breakup Model

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Wenliang Qi ◽  
Pingjian Ming ◽  
Ming Jia ◽  
Ye Peng ◽  
Chen Liu
Keyword(s):  
Diesel Engine ◽  
Oxygen Concentration ◽  
Ignition Delay ◽  
Soot Formation ◽  
Combustion Engine ◽  
Flame Stabilization ◽  
Emission Characteristics ◽  
Air Mixing ◽  
Hybrid Breakup Model ◽  
Breakup Model

Injection flow dynamics plays a significant role in fuel spray; this process controls the fuel–air mixing, which in turn is critical for the combustion and emissions process in diesel engine. In the current study, an integrated spray, combustion, and emission numerical model is developed for diesel engine computations based on the general transport equation analysis (GTEA) code. The model is first applied to predict the effect of turbulence inside the nozzle, which is considered by the submodel of hybrid breakup model on diesel spray process. The results indicate that turbulence term enhances the rate of breakup, resulting in more new droplets and smaller droplet sizes, leading to high evaporation rate with more evaporated mass. The model is also applied to simulate combustion and soot formation process of diesel. The effects of ambient density, ambient temperature, oxygen concentration and reaction mechanism on ignition delay, flame lift-off length, and soot formation are analyzed and discussed. The results show that although higher ambient density and temperature reduce the ignition delay and cause the flame stabilization location to move upstream, this is not helpful for fuel–air mixing because it increases the soot level in the fuel jet. While higher oxygen concentration has negative effects on soot formation. In addition, the model is employed to simulate the combustion and emission characteristics of a low-temperature combustion engine. The overall agreement between the measurements and predictions of in-cylinder pressure, heat release, and emission characteristics are satisfactory.

Delivering Sustainable Water Systems Using Kalman Filter and Statistical Approach

2017 ◽  
Vol 4 (1) ◽  
pp. 41-52
Author(s):  
Dedy Loebis
Keyword(s):  
Kalman Filtering ◽  
Statistical Approach ◽  
Water Systems ◽  
Data Sets ◽  
Pressure Data ◽  
Burst Event ◽  
Sample Data ◽  
Other Information ◽  
Supply Systems ◽  
Frequency Features

This paper presents the results of work undertaken to develop and test contrasting data analysis approaches for the detection of bursts/leaks and other anomalies within wate r supply systems at district meter area (DMA)level. This was conducted for Yorkshire Water (YW) sample data sets from the Harrogate and Dales (H&D), Yorkshire, United Kingdom water supply network as part of Project NEPTUNE EP/E003192/1 ). A data analysissystem based on Kalman filtering and statistical approach has been developed. The system has been applied to the analysis of flow and pressure data. The system was proved for one dataset case and have shown the ability to detect anomalies in flow and pres sure patterns, by correlating with other information. It will be shown that the Kalman/statistical approach is a promising approach at detecting subtle changes and higher frequency features, it has the potential to identify precursor features and smaller l eaks and hence could be useful for monitoring the development of leaks, prior to a large volume burst event.

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