Control-Oriented Model of Atkinson Cycle Engine With Variable Intake Valve Actuation

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
G. Murtaza ◽  
A. I. Bhatti ◽  
Q. Ahmed
Keyword(s):  
Engine Performance ◽  
Mean Value ◽  
Vital Role ◽  
Intake Valve ◽  
Valve Timing ◽  
Part Load ◽  
Engine Model ◽  
Atkinson Cycle ◽  
Engine Part ◽  
Proposed Model

With the advancement in the innovated technologies, optimum efficiency of spark ignition (SI) engine can be accomplished during the entire engine operating range, particularly at part load. In this research, a novel control-oriented extended mean value engine model (EMVEM) of the Atkinson cycle engine is proposed, wherein the Atkinson cycle, variable valve timing (VVT), overexpansion, and variable compression ratio (VCR) characteristics are incorporated. For this purpose, an intake valve timing (IVT) parameter is introduced, which has a vital role in modeling the inclusive dynamics of the system and to deal with engine performance degrading aspects. The proposed model is validated with the experimental data of a VVT engine, obtained from literature, to ensure that the proposed model has the capability to capture the dynamics of the Atkinson cycle engine, and engine load can be controlled by IVT parameter, instead of the conventional throttle. The potential benefits of late intake valve closing (LIVC) tactic and copious integrated characteristics are appreciated as well. Furthermore, simulation results of the developed model primarily indicate the reduction in the engine part load losses and enhancement in thermal efficiency due to overexpansion, which has a great significance in the enhancement of the performance, fuel economy, and emissions reduction. Besides, the constraints on LIVC and overexpansion become evident.

THE STUDY OF THE EFFECT OF INTAKE VALVE TIMING ON ENGINE USING CYLINDER DEACTIVATION TECHNIQUE VIA SIMULATION

2015 ◽  
Vol 77 (8) ◽  
Author(s):  
S. F. Zainal Abidin ◽  
M. F. Muhamad Said ◽  
Z. Abdul Latiff ◽  
I. Zahari ◽  
M. Said
Keyword(s):  
Fuel Consumption ◽  
Internal Combustion Engines ◽  
Gasoline Engine ◽  
Engine Performance ◽  
Intake Valve ◽  
Cylinder Deactivation ◽  
Part Load ◽  
Engine Model ◽  
Engine Efficiency ◽  
Load Conditions

There are many technologies that being developed to increase the efficiency of internal combustion engines as well as reducing their fuel consumption.  In this paper, the main area of focus is on cylinder deactivation (CDA) technology. CDA is mostly being applied on multi cylinders engines. CDA has the advantage to improve fuel consumption by reducing pumping losses at part load engine conditions. Here, the application of CDA on 1.6L four cylinders gasoline engine is studied. One-dimensional (1D) engine modeling work is performed to investigate the effect of intake valve strategy on engine performance with CDA. 1D engine model is constructed based on the 1.6L actual engine geometries. The model is simulated at various engine speeds at full load conditions. The simulated results show that the constructed model is well correlated to measured data. This correlated model is then used to investigate the CDA application at part load conditions. Also, the effects on the in-cylinder combustion as well as pumping losses are presented. The study shows that the effect of intake valve strategy is very significant on engine performance. Pumping losses is found to be reduced, thus improve fuel consumption and engine efficiency.

Design, Development, and Evaluation of a Control Framework for an Atkinson Cycle Engine

2017 ◽  
Vol 140 (5) ◽  
Author(s):  
G. Murtaza ◽  
A. I. Bhatti ◽  
Q. Ahmed
Keyword(s):  
Fuel Economy ◽  
Gasoline Engine ◽  
Thermodynamic Cycle ◽  
Mean Value ◽  
Operating Conditions ◽  
Intake Valve ◽  
Design Development ◽  
Engine Model ◽  
Atkinson Cycle ◽  
Control Framework

The efficiency of the spark ignition (SI) engine degrades while working at part loads. It can be optimally dealt with a slightly different thermodynamic cycle termed as an Atkinson cycle. It can be implemented in the conventional SI engines by incorporating advanced mechanisms as variable valve timing (VVT) and variable compression ratio (VCR). In this research, a control framework for the Atkinson cycle engine with flexible intake valve load control strategy is designed and developed. The control framework based on the extended mean value engine model (EMVEM) of the Atkinson cycle engine is evaluated in the view of fuel economy at the medium and higher load operating conditions for the standard new European driving cycle (NEDC), federal urban driving schedule (FUDS), and federal highway driving schedule (FHDS) cycles. In this context, the authors have already proposed a control-oriented EMVEM model of the Atkinson cycle engine with variable intake valve actuation. To demonstrate the potential benefits of the VCR Atkinson cycle VVT engine, for the various driving cycles, in the presence of auxiliary loads and uncertain road loads, its EMVEM model is simulated by using a controller having similar specifications as that of the conventional gasoline engine. The simulation results point toward the significant reduction in engine part load losses and improvement in the thermal efficiency. Consequently, considerable enhancement in the fuel economy of the VCR Atkinson cycle VVT engine is achieved over conventional Otto cycle engine during the NEDC, FUDS, and FHDS cycles.

Analysis of Variable Intake Runner Lengths and Intake Valve Open Timings on Engine Performances

2014 ◽  
Vol 663 ◽  
pp. 336-341 ◽  
Author(s):  
Mohd Farid Muhamad Said ◽  
Zulkarnain Abdul Latiff ◽  
Aminuddin Saat ◽  
Mazlan Said ◽  
Shaiful Fadzil Zainal Abidin
Keyword(s):  
Engine Performance ◽  
Intake Manifold ◽  
Intake Valve ◽  
Si Engine ◽  
Engine Simulation ◽  
Engine Model ◽  
Optimum Parameters ◽  
Comparison Results ◽  
Variable Valve ◽  
Engine Development

In this paper, engine simulation tool is used to investigate the effect of variable intake manifold and variable valve timing technologies on the engine performance at full load engine conditions. Here, an engine model of 1.6 litre four cylinders, four stroke spark ignition (SI) engine is constructed using GT-Power software to represent the real engine conditions. This constructed model is then correlated to the experimental data to make sure the accuracy of this model. The comparison results of volumetric efficiency (VE), intake manifold air pressure (MAP), exhaust manifold back pressure (BckPress) and brake specific fuel consumption (BSFC) show very well agreement with the differences of less than 4%. Then this correlated model is used to predict the engine performance at various intake runner lengths (IRL) and various intake valve open (IVO) timings. Design of experiment and optimisation tool are applied to obtain optimum parameters. Here, several configurations of IRL and IVO timing are proposed to give several options during the engine development work. A significant improvement is found at configuration of variable IVO timing and variable IRL compared to fixed IVO timing and fixed IRL.

First Principle-Based Control Oriented Model of a Gasoline Engine

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Ahmed Yar ◽  
A. I. Bhatti ◽  
Qadeer Ahmed
Keyword(s):  
Mathematical Model ◽  
Gasoline Engine ◽  
Mean Value ◽  
First Principle ◽  
Unified Framework ◽  
Engine Model ◽  
Proposed Model ◽  
Suitable Form ◽  
Speed Fluctuations ◽  
The Mathematical Model

A first principle based-control oriented gasoline engine model is proposed that is based on the mathematical model of the actual piston and crankshaft mechanism. Unlike conventional mean value engine models (MVEMs), which involve approximating the torque production mechanism with a volumetric pump, the proposed model obviates this rather over-simplistic assumption. The alleviation of this assumption leads to the additional features in the model such as crankshaft speed fluctuations and tension in bodies forming the mechanism. The torque production dynamics are derived through Lagrangian mechanics. The derived equations are reduced to a suitable form that can be easily used in the control-oriented model. As a result, the abstraction level is greatly reduced between the engine system and the mathematical model. The proposed model is validated successfully against a commercially available 1.3 L gasoline engine. Being a transparent and more capable model, the proposed model can offer better insight into the engine dynamics, improved control design and diagnosis solutions, and that too, in a unified framework.

scholarly journals Characterization of Performance of Short Stroke Engines with Valve Timing for Blended Bioethanol Internal Combustion

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 759 ◽  
Author(s):  
Kun-Ho Chen ◽  
Yei-Chin Chao
Keyword(s):  
Co2 Emissions ◽  
Ignition Time ◽  
Engine Performance ◽  
Valve Timing ◽  
Atkinson Cycle ◽  
Blended Fuel ◽  
Exhaust Valves ◽  
Blended Fuels ◽  
Stroke Engine

The present study provides a feasible strategy for minimizing automotive CO2 emissions by coupling the principle of the Atkinson cycle with the use of bioethanol fuel. Motor cycles and scooters have a stroke to bore ratio of less than unity, which allows higher speeds. The expansion to compression ratio (ECR) of these engines can be altered by tuning the opening time of the intake and exhaust valves. The effect of ECR on fuel consumption and the feasibility of ethanol fuels are still not clear, especially for short stroke engines. Hence, in this study, the valve timing of a short stroke engine was tuned in order to explore potential bioethanol applications. The effect of valve timing on engine performance was theoretically and experimentally investigated. In addition, the application of ethanol/gasoline blended fuels, E3, E20, E50, and E85, were examined. The results show that consumption, as well as engine performance of short stroke motorcycle engines, can be improved by correctly setting the valve controls. In addition, ethanol/gasoline blended fuel can be used up to a composition of 20% without engine modification. The ignition time needs to be adjusted in fuel with higher compositions of blended ethanol. The fuel economy of a short stroke engine cannot be sharply improved using an Atkinson cycle, but CO2 emissions can be reduced using ethanol/gasoline blended fuel. The present study demonstrates the effect of ECR on the performance of short stroke engines, and explores the feasibility of applying ethanol/gasoline blended fuel to it.

In-cylinder boosting of turbocharged spark-ignited engines. Part 1: Model-based design of the charge valve

2012 ◽  
Vol 226 (10) ◽  
pp. 1408-1418 ◽  
Author(s):  
Christoph Voser ◽  
Christian Dönitz ◽  
Gregor Ochsner ◽  
Christopher Onder ◽  
Lino Guzzella
Keyword(s):  
System Design ◽  
Engine Performance ◽  
Companion Paper ◽  
Mean Value ◽  
Maximal Power ◽  
Trade Off ◽  
Engine Model ◽  
Model Based ◽  
Variable Valve ◽  
System Characteristics

Downsizing and turbocharging for retaining the maximal power is a widely used approach to decrease the fuel consumption of spark ignited engines. In general, the trade-off is a substantial driveability loss. In-cylinder boosting has proven to be an effective way to eliminate this problem. Thus far, expensive and complex fully variable valve-trains have been proposed for the air exchange between the air tank and the combustion chamber. This paper is the first of a two-part study that examines the use of a deactivatable camshaft-driven valve with respect to the achievable transient engine performance. The system characteristics and limitations are discussed by using a mean value engine model that is adapted for in-cylinder boosting. A model-based design framework is presented which links the valve system design to a desired engine performance. The companion paper covers control issues and provides experimental verifications.

scholarly journals PENCAPAIAN PERFORMA PADA KATUP VARIABEL TIMING FIXED TIMING UNTUK MESIN YANG OPTIMAL

2012 ◽  
Vol 11 (1) ◽  
pp. 68
Author(s):  
KETUT ASTAWA
Keyword(s):  
Engine Performance ◽  
Variable Valve Timing ◽  
Intake Valve ◽  
Valve Timing ◽  
Static Test ◽  
Load Transmission ◽  
Valve Opening ◽  
Efficient Machine ◽  
Hc Emissions ◽  
Variable Valve

Problems will be discussed in this research is how differences in exhaust emissions generatedby engine with variable valve timing and valve timing on a fixed volume of motor vehiclecylinder 1300 cc. Variable valve timing technology, which is set when opening and closingthe intake valve (intake valve) electronic fuel according to engine conditions. This will makemixing air and fuel that enters into an efficient machine that will produce great power, fueleconomy and low emissions. Research emissions (CO, CO2, HC, O2) was performedwith dynamictesting, where the vehicle in a state of the load lifted and given transmission. Unlikethe testing generally performed with a static test, in which the vehicle is at rest and without aload. This test is performed to determine how the condition of exhaust gases when the vehicledynamic (analogous to the vehicle running). In general, machines with variable valve timingto produce better emissions than engines with fixed valve timing. The higher the spin machineand load transmission system will result in CO and HC emissions are decreased and O2 andCO2 increased. Engine with variable valve timing control the suction valve opening times toachieve optimum engine performance at various driving conditions. And set out the engineoutput as needed.

scholarly journals The tuning of a small four-stroke spark ignition engine for flexible valve timings through numerical approach

2019 ◽  
Vol 255 ◽  
pp. 04004
Author(s):  
M. Haziq Adham Rosli ◽  
M. Razali Hanipah ◽  
Maurice Kettner
Keyword(s):  
Combustion Engine ◽  
Engine Performance ◽  
Numerical Approach ◽  
Spark Ignition Engine ◽  
Variable Valve Timing ◽  
Intake Valve ◽  
Valve Timing ◽  
Engineering Research ◽  
Numerical Assessment ◽  
Variable Valve

Variable valve timing has been implemented by various manufacturers to improve internal combustion engine performance while operating at wide speed and load ranges. A novel flexible valve timing system for a small four-stroke engine is currently under development by Automotive Engineering Research Group (AERG) in Universiti Malaysia Pahang (UMP). In this paper, a comprehensive intake and exhaust tuning for the flexible variable valve timing is presented. A numerical assessment has been conducted through one dimensional engine modelling and simulation using validated model. There are eight valve timing configurations investigated for the tuning for three main speed regions. The simulation shows a positive and significant impact to the engine performance in three approaches; namely late intake valve closing, early intake valve closing and late exhaust valve closing. These approaches sufficiently covered the whole range of engine speeds for optimum engine operational performance.

Combined Effects of Variable Intake Manifold Length, Variable Valve Timing and Duration on the Performance of an Internal Combustion Engine

2017 ◽  
Author(s):  
P. Sawant ◽  
S. Bari
Keyword(s):  
Combustion Engine ◽  
Engine Performance ◽  
Internal Combustion ◽  
Intake Manifold ◽  
Combined Effects ◽  
Performance Parameters ◽  
Intake Valve ◽  
Valve Timing ◽  
Ic Engine ◽  
Speed Range

Naturally aspirated internal combustion (IC) engines with a fixed intake assembly are generally tuned to produce an induction boost at a single engine speed by capitalizing the induction pressure waves only over a narrow speed range. This paper investigates the individual and combined effects of varying intake runner length and intake valve timing on the performance parameters of an IC engine at engine speeds from 3000 rpm to 9000 rpm. The 1-D model of the KTM SI engine built for simulations in Ricardo Wave software is validated with 98% accuracy against experimental test results. The performance parameters thus obtained, as a combined effect, show an average improvement of 7.02% throughout the engine’s speed range. With the co-existence of variable length intake runners and variable intake valve opening timing, the required number of variations to boost the engine performance are found to be reduced making variable intake assembly more feasible.

Numerical Study of SI Engine Part Load Operating Conditions Using Different VVA Strategies

2011 ◽  
Author(s):  
Michele Battistoni ◽  
Carlo N. Grimaldi ◽  
Francesco Mariani
Keyword(s):  
Numerical Study ◽  
Control Strategies ◽  
Fluid Dynamic ◽  
Operating Conditions ◽  
Load Control ◽  
Valve Closure ◽  
Intake Valve ◽  
Flamelet Model ◽  
Part Load ◽  
Engine Model

In SI engines, VVA (Variable Valve Actuation) technology is mainly used for the reduction of pumping losses at part load. This paper presents the results of fluid dynamic analyses on a 4V engine about the effects of different VVA strategies, by comparing and discussing the results in terms of organized charge motions, turbulence levels, flame developments, NO and CO emissions. CFD simulations cover five load control cases: comparison is among conventional throttling, EIVC (Early Intake Valve Closure) with symmetric and asymmetric intake lifts, LIVC (Late Intake Valve Closure) and symmetrical Multi-Lift strategies. 3D U-RANS simulations are performed, adopting the Extended Coherent Flamelet Model (ECFM) for the description of premixed SI combustion. The 3D model is also coupled to a 1D engine model which provides inlet/outlet boundary conditions. Simulation results highlight the potential of asymmetric Early Intake Valve Closure (EIVC) strategy which allows reducing pumping losses and, at the same time, achieving good turbulence intensity and combustion speed, if compared to other load control strategies. Multi-Lift strategy resulted excellent in terms of burn duration, but pumping losses are practically the same as in the throttled engine.

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