CFD Modelling of the Effects of Exhaust Gas Recirculation (EGR) and Injection Timing on Diesel Combustion and Emissions

2017 ◽  
Author(s):  
Ishan Verma ◽  
Ellen Meeks ◽  
Eric Bish ◽  
Martin Kuntz ◽  
Karthik Puduppakkam ◽  
...  
Keyword(s):  
Exhaust Gas Recirculation ◽  
Injection Timing ◽  
Exhaust Gas ◽  
Diesel Combustion ◽  
Cfd Modelling ◽  
Gas Recirculation

Model-based control of diesel engines with multiple fuel injections

2017 ◽  
Vol 19 (2) ◽  
pp. 257-265 ◽  
Author(s):  
Yudai Yamasaki ◽  
Ryosuke Ikemura ◽  
Shigehiko Kaneko
Keyword(s):  
Fuel Injection ◽  
Exhaust Gas Recirculation ◽  
Gas Pressure ◽  
Combustion Model ◽  
Injection Timing ◽  
Exhaust Gas ◽  
Diesel Combustion ◽  
Target Value ◽  
Pressure Peak ◽  
Gas Recirculation

We developed a feed-forward controller for a conventional diesel combustion engine with triple fuel injection and experimentally evaluated its performance. A combustion model that discretizes an engine cycle into a number of representative points to achieve a light calculation load is embedded into the controller; this model predicts the in-cylinder gas-pressure-peak timing with information about the operating condition obtained from the engine control unit. The controller calculates the optimal main-fuel-injection timing to control the in-cylinder gas-pressure peak using the prediction result as a controller with a single input and output. The controller’s performance was evaluated by experiments using a four-cylinder diesel engine under changing the target value of the in-cylinder gas-pressure-peak timing during a target-following test and the performance was also evaluated under changing the exhaust gas recirculation ratio at the constant target value of the in-cylinder gas-pressure-peak timing for the disturbance-response test. It was found that the controller could calculate the optimal main-injection timing over a cycle and maintain the targeted in-cylinder gas-pressure-peak timing even when the target value or exhaust gas recirculation changed. The combustion model was also shown to be fast enough at predicting diesel combustion for onboard control.

In-cylinder stratification of external exhaust gas recirculation for controlling diesel combustion

2009 ◽  
Vol 11 (1) ◽  
pp. 1-15 ◽  
Author(s):  
T Fuyuto ◽  
M Nagata ◽  
Y Hotta ◽  
K Inagaki ◽  
K Nakakita ◽  
...  
Keyword(s):  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Diesel Combustion ◽  
Gas Recirculation

Control-Oriented Physics-Based NOX Emission Model for a Diesel Engine With Exhaust Gas Recirculation

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Saravanan Duraiarasan ◽  
Rasoul Salehi ◽  
Anna Stefanopoulou ◽  
Siddharth Mahesh ◽  
Marc Allain
Keyword(s):  
Diesel Engine ◽  
Test Procedure ◽  
Flame Temperature ◽  
Exhaust Gas Recirculation ◽  
Nox Emission ◽  
Injection Timing ◽  
Exhaust Gas ◽  
Engine Control ◽  
Gas Recirculation ◽  
The Impact

Abstract Stringent NOX emission norm for heavy duty vehicles motivates the use of predictive models to reduce emissions of diesel engines by coordinating engine parameters and aftertreatment. In this paper, a physics-based control-oriented NOX model is presented to estimate the feedgas NOX for a diesel engine. This cycle-averaged NOX model is able to capture the impact of all major diesel engine control variables including the fuel injection timing, injection pressure, and injection rate, as well as the effect of cylinder charge dilution and intake pressure on the emissions. The impact of the cylinder charge dilution controlled by the engine exhaust gas recirculation (EGR) in the highly diluted diesel engine of this work is modeled using an adiabatic flame temperature predictor. The model structure is developed such that it can be embedded in an engine control unit without any need for an in-cylinder pressure sensor. In addition, details of this physics-based NOX model are presented along with a step-by-step model parameter identification procedure and experimental validation at both steady-state and transient conditions. Over a complete federal test procedure (FTP) cycle, on a cumulative basis the model prediction was more than 93% accurate.

Effect of hydraulic flow rate, injection timing, and exhaust gas recirculation on particulate and gaseous emissions in a light-duty diesel engine

2019 ◽  
Vol 234 (5) ◽  
pp. 1279-1293 ◽  
Author(s):  
Khawar Mohiuddin ◽  
Minhoo Choi ◽  
Junkyu Park ◽  
Sungwook Park
Keyword(s):  
Diesel Engine ◽  
Flow Rate ◽  
Particle Number ◽  
Exhaust Gas Recirculation ◽  
Injection Timing ◽  
Exhaust Gas ◽  
Gaseous Emissions ◽  
Spray Tip Penetration ◽  
Hydraulic Flow ◽  
Gas Recirculation

Nozzle hydraulic flow rate is a critical parameter that affects the combustion process and plays a vital role in the production of emissions from a diesel engine. In this study, injection characteristics, such as normalized injection rate and spray tip penetration, were analyzed for different hydraulic flow rate injectors with the help of spray experiments. To further investigate the effects of hydraulic flow rate on engine-out particulate and gaseous emissions, engine experiments were performed for different values of hydraulic flow rate in multiple injectors. Various operating conditions and loading configurations were examined, and the effects of varying start of injection and exhaust gas recirculation rates for different hydraulic flow rates were analyzed. A separate Pegasor Particle Sensor (PPS-M) sensor was used to measure and collect data on the particle number, and an analysis was conducted to investigate the relation of particle number with hydraulic flow rate, injection timing, and exhaust gas recirculation rate. Results of the spray experiment exhibited a decreasing injection duration and increasing spray tip penetration with increasing hydraulic flow rate. Effect of hydraulic flow rate on combustion and emission characteristics were analyzed from engine experiment results. Least ignition delay was achieved using a smaller hole diameter, retarded injection timing, and lowest EGR%. Higher hydraulic flow rate with retarded injection timing and higher EGR% helped in reduction of NOx emissions and brake-specific fuel consumption, but particulate emissions were increased. Best particulate matter–NOx trade-off was achieved with lowest hydraulic flow rate.

An experimental investigation on performance, emissions, and combustion in a manifold injection for different exhaust gas recirculation flowrates in hydrogen—diesel dual-fuel operations

2008 ◽  
Vol 222 (11) ◽  
pp. 2131-2145 ◽  
Author(s):  
N Saravanan ◽  
G Nagarajan
Keyword(s):  
Experimental Investigation ◽  
Exhaust Gas Recirculation ◽  
Intake Manifold ◽  
Dual Fuel ◽  
Injection Timing ◽  
Exhaust Gas ◽  
Exhaust Gases ◽  
Injection Duration ◽  
Performance And Emissions ◽  
Gas Recirculation

Hydrogen is receiving considerable attention as an alternative fuel to replace the rapidly depleting petroleum-based fuels. Its clean burning characteristics help to meet the stringent emission norms. In this experimental investigation a single-cylinder diesel engine was converted to operate in hydrogen—diesel dual-fuel mode. Hydrogen was injected in the intake manifold and the diesel was injected directly inside the cylinder. The injection timing and the injection duration of hydrogen were optimized on the basis of performance and emissions. Best results were obtained with hydrogen injection at gas exchange top dead centre with an injection duration of 30° crank angle. The flowrate of hydrogen was optimized as 7.5l/min with optimized injection timing and duration. The optimized exhaust gas recirculation (EGR) flowrate was 20 per cent at 75 per cent load. The optimized timings were chosen on the basis of performance, emission, and combustion characteristics. The EGR technique was adopted in the hydrogen—diesel dual-fuel mode by varying the EGR flowrate from 0 per cent to 25 per cent in steps of 5 per cent. The maximum quantity of exhaust gases recycled during the test was 25 per cent (up to 75 per cent load); beyond that unstable combustion was observed with an increase in smoke. The brake thermal efficiency with 20 per cent EGR decreases by 9 per cent compared with diesel. The nitrogen oxide (NO x) emission in hydrogen manifold injection decreases by threefold with 20 per cent EGR operation at full load. The NO x emission tends to reduce drastically with increase in the EGR percentage at all load conditions owing to the increase in heat capacity of the exhaust gases. The smoke decreases by 80 per cent in the dual-fuel operation compared with diesel at 75 per cent load.

scholarly journals Influence of Exhaust Gas Recirculation, and Injection Timing on the Combustion, Performance and Emission Characteristics of a Cylinder Head Porous Medium Engine

2015 ◽  
Vol 2015 ◽  
pp. 1-10
Author(s):  
Chidambaram Kannan ◽  
Thulasi Vijayakumar
Keyword(s):  
Combustion Chamber ◽  
Cylinder Head ◽  
Research Work ◽  
Exhaust Gas Recirculation ◽  
Injection Timing ◽  
Emission Characteristics ◽  
Exhaust Gas ◽  
Performance And Emission ◽  
Homogeneous Combustion ◽  
Gas Recirculation

Homogeneous combustion has the potential of achieving both near-zero emissions and low specific fuel consumption. However, the accomplishment of homogeneous combustion depends on the air flow structure inside the combustion chamber, fuel injection conditions, and turbulence as well as ignition conditions. Various methods and procedures are being adopted to establish the homogeneous combustion inside the engine cylinder. In this research work, a highly porous ceramic structure was introduced into the combustion chamber (underside of the cylinder head). The influence of operating parameters such as exhaust gas recirculation (EGR) and injection timing on the combustion, performance, and emission characteristics of such developed engine was investigated in this research work.

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