Numerical Analysis of Unsteady Exhaust Gas Flow and Its Application for Lambda Control Improvement

A multidimensional computational fluid dynamics (CFD) tool has been applied to analyze the exhaust system of a gasoline engine. Since gas flow in the exhaust manifold is affected by exhaust pulsations, prediction methods based on steady flow are not able to predict gas flow precisely enough. Therefore, a new multidimensional calculation method, called pulsation flow calculation, has been developed. A one-dimensional gas exchange simulation and a three-dimensional exhaust gas flow calculation are combined to simulate gas flow pulsations caused by the gas exchange process. Predicted gas flow in the exhaust manifold agreed with the experimental data. With the aim of reducing emissions, the pulsation flow calculation method has been applied to improve lambda feedback control using an oxygen sensor. The factors governing sensor sensitivity to the exhaust gas from each cylinder were clarified. The possibility of selecting the oxygen sensor location in the exhaust manifold on the basis of calculations was proved. The effect of an exhaust manifold with equal-length cylinder runners on achieving uniform sensor sensitivities was made clear. In addition, a new lambda feedback control method for an exhaust manifold with different-length cylinder runners is proposed.

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Adaptation for Air-Intake System Throttle Control in a Gasoline Engine With Low-Pressure Exhaust-Gas Recirculation

Volume 1: Adaptive and Intelligent Systems Control; Advances in Control Design Methods; Advances in Non-Linear and Optimal Control; Advances in Robotics; Advances in Wind Energy Systems; Aerospace Applications; Aerospace Power Optimization; Assistive Robotics; Automotive 2: Hybrid Electric Vehicles; Automotive 3: Internal Combustion Engines; Automotive Engine Control; Battery Management; Bio Engineering Applications; Biomed and Neural Systems; Connected Vehicles; Control of Robotic Systems ◽

10.1115/dscc2015-9657 ◽

2015 ◽

Author(s):

Mario Santillo ◽

Suzanne Wait ◽

Julia Buckland

Keyword(s):

Feedback Control ◽

Control Strategy ◽

Gasoline Engine ◽

Exhaust Gas Recirculation ◽

Lookup Table ◽

Exhaust Gas ◽

Feed Forward ◽

Intake System ◽

Air Intake ◽

Gas Recirculation

We investigate control strategies for traditional throttle-in-bore as well as low-cost cartridge-style throttle bodies for the air-intake system (AIS) throttle used in low-pressure exhaust-gas recirculation (LPEGR) on a turbocharged gasoline engine. Pressure sensors placed upstream and downstream of the AIS throttle are available as signals from the vehicle’s engine control unit, however, we do not use high-bandwidth feedback control of the AIS throttle in order to maintain frequency separation from the higher-rate EGR loop, which uses the downstream pressure sensor for feedback control. A design-of-experiments conducted using a feed-forward lookup table-based AIS throttle control strategy exposes controller sensitivity to part-to-part variations. For accurate tracking in the presence of these variations, we explore the use of adaptive feedback control. In particular, we use an algebraic model representing the throttle plate effective opening area to develop a recursive least-squares (RLS)-based estimation routine. A low-pass filtered version of the estimated model parameters is subsequently used in the forward-path AIS throttle controller. Results are presented comparing the RLS-based feedback algorithm with the feed-forward lookup table-based control strategy. RLS is able to adapt for part-to-part and change-over-time variabilities and exhibits an improved steady-state tracking response compared to the feed-forward control strategy.

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The use of low grade bio ethanol as fuel mixer in gasoline engine with optimization compact distillator

E3S Web of Conferences ◽

10.1051/e3sconf/20186702004 ◽

2018 ◽

Vol 67 ◽

pp. 02004

Author(s):

Iqbal Yamin ◽

Bambang Sugiarto ◽

Setia Abikusna ◽

Dedi Suntoro

Keyword(s):

Alternative Energy ◽

Gas Flow ◽

Gasoline Engine ◽

Ethanol Vapor ◽

Energy Development ◽

Green Energy ◽

Low Grade ◽

Exhaust Gas ◽

High Grade ◽

Alternative Energy Sources

Limited fossil energy resources need to encourage renewable energy development and energy conservation it is called green energy development. One of the alternative energy sources used are bioethanol, from low grade is converted into high grade through distillation process with distillator compact that will be used as a mixture of gasoline. Tests compact distillator consisting of evaporator Indonesia Kampus, separator, and condenser by utilizing exhaust gas to heat distillator already filled with low grade bioethanol, so the heat transfer occurs on the surface of the exhaust into the evaporator chamber. In the evaporator will transform ethanol into the vapor phase. Ethanol vapor flows into the separator, with a mechanism in it is expected that water vapor will evaporate participate separately with ethanol vapor. Ethanol vapors from this distillation will flow to the condenser and will be turned into liquid, the liquid is as high grade bioethanol would be the fuel mixing gasoline. In early studies, distillation rate was 98.5 ml/h with 67% ethanol content. Optimization compact distillator is done by adding the valve at the evaporator branch. When heat has reached 80°C exhaust gas flow to the evaporator chamber is closed. As a result, the heat from the evaporator can be detained and not rise significantly. Further optimization is to change the design of the separator through theoretical and empirical calculations with some assumptions based on the rule of thumb in the field of distillation, adding insulation to reduce heat leakage, as well as varying the feed volume and feed concentrate ethanol. In the end, based on the parameters of the distillation rate and ethanol concentrate, compact distillator with distances between tray 100 mm, volume 800 ml, engine speed 5.400 rpm can produce distillation rate of 274.3 ml/hr and ethanol concentrate of 88.97%.

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Gas flow calculation method of a ramjet engine

10.1063/1.5009883 ◽

2017 ◽

Cited By ~ 4

Author(s):

Kirill Kostyushin ◽

Anuar Kagenov ◽

Ivan Eremin ◽

Konstantin Zhiltsov ◽

Vladimir Shuvarikov

Keyword(s):

Calculation Method ◽

Gas Flow ◽

Flow Calculation ◽

Ramjet Engine

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G111 Observation of Unsteady Exhaust-Gas Flow from a Gasoline Engine by Infrared Thermography

The Proceedings of the Thermal Engineering Conference ◽

10.1299/jsmeted.2010.179 ◽

2010 ◽

Vol 2010 (0) ◽

pp. 179-180

Author(s):

Shohei MATSUI ◽

Ryosuke OKUNISHI ◽

Masaya OTA ◽

Jiro FUNAKI ◽

Katsuya HIRATA

Keyword(s):

Infrared Thermography ◽

Gas Flow ◽

Gasoline Engine ◽

Exhaust Gas

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Modulated fuel feedback control of a fuel injection engine using a switch type oxygen sensor

Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering ◽

10.1243/0954407971526605 ◽

1997 ◽

Vol 211 (6) ◽

pp. 491-497 ◽

Cited By ~ 1

Author(s):

K S Park ◽

J Park ◽

S K Kauh ◽

S T Ro ◽

J Lee

Keyword(s):

Feedback Control ◽

Oxygen Sensor ◽

Fuel Injection ◽

Control Method ◽

Modulation Method ◽

Control Logic ◽

Fuel Ratio ◽

Switch Type ◽

Three Way Catalyst ◽

Ramp Control

The jump—ramp control algorithm has been widely adopted for the air—fuel ratio control in a fuel injection spark ignition (SI) engine by using a conventional on—off type oxygen sensor. But the jump—ramp control method has limitations in improving the frequency and amplitude of the air—fuel ratio oscillation. This study suggests a new feedback control logic called modulated fuel feedback control, which has a concept of pretuned air—fuel ratio oscillation. In the modulation method, the oxygen sensor output is not treated as on—off but as an analogue for feedback. By using the modulation method, the frequency and amplitude of the air—fuel ratio oscillation can be controllable to some extent to improve the conversion efficiency of a three-way catalyst. The results show that the performance of the modulation method is better than that of the jump—ramp control method in reducing the amplitude of the air—fuel ratio oscillation as well as in increasing the frequency of the air—fuel ratio oscillation.

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A “Hot and Cold” Experimental Analysis of Flow Distribution in a “Close Coupled” Catalytic Converter

Design, Operation, and Application of Modern Internal Combustion Engines and Associated Systems ◽

10.1115/ices2002-454 ◽

2002 ◽

Cited By ~ 1

Author(s):

M. Cardone ◽

V. Cioffi ◽

R. Fiorenza ◽

P. Gaudino ◽

A. Senatore ◽

...

Keyword(s):

Gas Flow ◽

Oxygen Sensor ◽

Catalytic Converter ◽

Engine Performance ◽

Flow Distribution ◽

Integrated Modelling ◽

Critical Parameters ◽

Exhaust Manifold ◽

Gas Treatment ◽

Intake Flow

The tighter limits introduced by EURO3 and EURO4 regulations involve the adoption of exhaust configurations, in which the converter is located close to the manifold, in order to reduce light off time, and so to obtain lower emissions. This type of configuration introduces new problems relative to optimisation of the exhaust manifold geometry, which is no longer only linked to engine performance, but also has to guarantee the best possible operation of the exhaust gas treatment system. Critical parameters include lambda probe positioning and impingement of the gas flow, along with establishment of a flow field that corresponds to the catalytic converter intake area, as imposed by well known requests of reliability and functionality. The present work is aimed at integrated modelling and experimental optimisation of exhaust manifold geometry, with regard to oxygen sensor positioning and catalyst intake flow distribution, to find the best compromise between engine performance and exhaust emissions control.

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