Figures - uploaded by Prateek Chaturvedi

Author content

All figure content in this area was uploaded by Prateek Chaturvedi

Content may be subject to copyright.

ResearchGate Logo

Discover the world's research

  • 20+ million members
  • 135+ million publications
  • 700k+ research projects

Join for free

2018 International Conference on Automation and Computational Engineering (ICACE - 2018)

Amity University Greater Noida Campus, U. P., India, Oct 3-4, 2018.

20

978-1-5386-5464-4/18/$31.00 ©2018 IEEE

To Study the Theoretical and Practical Valve Timing

Difference of a Four Stroke Engine and to Rectify the

Variation

Mayank Sharma

Student, B. Tech.,

Department of MAE

Amity University, Greater Noida Campus

mayanksharma.mayank1122@gmail.com

Prateek Chaturvedi

Assistant Professor,

Department of ME

Amity University, Greater

Noida Campus

prateekonmail@gmail.com

Dr Anish Gupta

Assistant Dean Academics,

Amity University, Greater

Noida Campus

gupta.anish01@gmail.com

Abstract: In this paper different methods and techniques are

reviewed so that we can achieve a high rate of efficiency and

performance because nowadays in most of the commercial engines

there is a delay in the opening of the intake valve and closing of the

exhaust valve which reduces the efficiency of the engine and also

reduces the performance of the engine in a very short period. The aim

is to find the most efficient and economical method to rectify the

difference between theoretical and actual valve timing of four stroke

engine. The study concluded to propose a valve timing mechanism

controlled by the solenoid valve, electrically operated to through

automation for actuation of the valves

.

Keywords: spark ignition (SI),variable valve timing (VVT),

variable valve actuation (VVA), exhaust gas recirculation (EGR),

variable cam tim ing (VCT)

I. INTRODUCTION:

In the cutting-edge world, one of the biggest concerns is the

regularly exhausting supply of oil. The car business

particularly affected, in 2011, the world devoured 85

million barrels of oil a day [9]. The oil still a critical

wellspring of vitality also it is into what's to come. Despite

the world utilization of petroleum products keep on

growing to 118 million barrels for each day by 2030. In

addition, the discharged emanation from internal

combustion engine contaminating the earth. The worldwide

interest for autos is taking off one conjecture has the

quantity of overall autos expanding five-overlay by 2050 to

2.9 billion [8].

The control of Greenhouse gas discharge has started to

include the various requirements that vehicle producers to

full fill. The engine fuel utilization diminishment turns into

an essential necessity for producers and creators, and

additionally it must meet the present and future discharge

enactments normally The most important thing for all

engine manufacturers is to reduce the wastage of fuel due to

opening and closing of the valve using the camshaft, as we

know the inlet valve does not open or close on exact time

when required, it opens and closes gradually due to which

there is excess flow of fuel in the combustion chamber

which causes these wastage and effects the engine

efficiency.

Camshaft: A camshaft is a pole to which a cam is affixed

or of which a cam shapes a vital part. In internal

combustion engines with cylinders, the camshaft is utilized

to work poppet valves [4]. It comprises of a round and

hollow bar running the length of the chamber keep money

with various elliptical flaps projecting from it, one for every

valve. The cam flaps drive the valves open by pushing on

the valve, or on some transitional system, as they turn.

Crankshaft: A crankshaft is a mechanical part ready to

play out a transformation between responding movement

and rotational movement [4]. In a responding engine, it

interprets responding movement of the cylinder into

rotational movement; while in a responding compressor, it

changes over the rotational movement into responding

movement. To do the transformation between two

movements, the crankshaft has "wrench tosses" or

"crankpins", extra bearing surfaces whose pivot is balanced

from that of the wrench, to which the "enormous finishes"

of the associating bars from every barrel connect.

VVT: In internal combustion engines, variable valve timing

(VVT) is the way toward changing the planning of a valve

lift occasion, and is frequently used to enhance execution,

mileage or outflows. It is progressively being utilized as a

part of mix with variable valve lift frameworks.

Lecture review:

I. VARIABLE CAM TIMING AND

CONSEQUENCES

One target of this paper is to reduce fuel consumption and

enhance the working of variable cam timing system and

also evaluate their accoutrements on engine control system

layout [1].

Variable valve timing (VVT) helps to boost the fuel

economy, decrease discharge and escalation of peak torque.

There are many VVT systems like cam figure replacing,

volatile intake or exhaust duration, volatile valve drive,

camless engine arrangement but only volatile cam phasing

scheme. The main affair of this research is to tell the effects

of volatile cam timings on engine working and their

importance on engine curb system layout [11].

2018 International Conference on Automation and Computational Engineering (ICACE - 2018)

Amity University Greater Noida Campus, U. P., India, Oct 3-4, 2018.

21

There were four VCT effect which are as follows: -

1. Decreasing the exhaust cam time leads to

development of exhaust gas residual and decreases

the NO2 discharge and also reduces pumping fall

at part load.

2. When intake cam timing is reduced the volumetric

efficiency is also reduced, especially at very less

engine acceleration, which decreases pumping

loss.

3. Propelling admission cam timing up to a point,

increments volumetric proficiency and pinnacle

engine torque at low and medium paces.

4. Higher confirmation advances can in like manner

be used to reuse exhaust gas to lessen NO2

transmissions and pumping mishaps.

In this paper many modes of variable cam timing engine is

suggested and numerous control calculations are checked

on.

Fig. 1Profiles of intake and exhaust valve lifts versus

crank angle [1].

II. INVESTIGATION OF VARIABLE VALVE

TIMING PROCEDURE

This paper tells us about the techniques used in VVT for

intake of fuel air mixture and releasing waste gases, and

this paper also tells us about the effects on pressure volume

course on engine [2].

In internal combustion engine, especially for (SI) engine,

valve moments plays very important role on engine

efficiency and waste gases releasing. With the help of VVT

technology we can control the valve moments, valve

timings at any position of engine which helps in

improvement of engine efficiency [3].

Fig. 2Valve timing diagram in connection with PV chart for

traditional four-stroke SI engine [3]

Losses of pumping really on opening and closing area of

the acceleration valve and lose increases when acceleration

valve is going to close and are very less when acceleration

valve is completely open, so the pumping loses are not

directly proportional with the engine load.

In this paper many intakes as well as exhaust valve timing

techniques been examined which have their personal profits

and losses. Intake-valve timing is the most important

criterion for measuring the low and high-speed volumetric

ability [12].

For getting all the benefits from VVT there are mainly two

important things to consider:

1. It should be cost effective, very less complex,

stable valve time mechanism.

2. Understanding the profits by changing valve

timing and all of its accoutrements on PV cycle of

the engine.

III. EFFECTS OF IGNITION TIMING ON

GASOLINE ENGINE

In this paper it is evaluated weather variable valve timing

can effect on engine performance of spark ignition engine.

Methodology used:

For accomplishing this objective, at a speed of 3400 rpm,

the start timing has been changed in the scope of 41° BTDC

to 10° ATDC and for advance task, start timing has been

planned at totally open throttle what's more, finally, the

execution qualities, for example, control, torque, BMEP,

volumetric effectiveness and discharges are gotten and

talked about [5].

2018 International Conference on Automation and Computational Engineering (ICACE - 2018)

Amity University Greater Noida Campus, U. P., India, Oct 3-4, 2018.

22

Fig. 3 The connection between deplete temperature and

in chamber top weight versus start timing-totally open

throttle; equality proportion of one [5].

Outcomes:

The outcomes demonstrate ideal power and torque is

accomplished at 31°CA preceding best perfectly focused

and volumetric proficiency, BMEP have expanded with

rising start timing. O2, CO2, CO has been relatively steady,

however HC with progress of start timing expanded and the

most reduced sum NOx is acquired at 10 BTDC.

Conclusion:

It got that start timing can be utilized as an elective route

for anticipating the execution of internal ignition engines.

Additionally, engine speed furthermore, throttle position

were altogether found to essentially impact execution in this

engine.

IV. VARIABLE VALVE TIMING FOR REDUCING

FUEL CONSUMPTION

In this paper, the affectability examination and Quasi-

Newton calculations are utilized to improve valve timing

XU7/L3 engine with a specific end goal to lessen fuel

utilization and increment engine execution. At initially, all

parts of engine are demonstrated in GT-POWER and a

correlation with test comes about is performed to affirm the

exactness of the model. At that point, GT-POWER display

is combined with MATLAB-SIMULINK to control sources

of info and yields with affectability examination and Quasi-

Newton calculations. The outcomes acquired demonstrate

that ideal valve timing essentially diminishes brake

particular fuel utilization (BSFC). Besides, the merging rate

of Quasi-Newton calculation for achieving the ideal point is

higher than the one of affectability examination calculation

[6].

Results obtained:

1. The merged speed of the Quasi-Newton

calculation for coming to the enhanced point is

considerably higher than affectability

investigation. This comes about because of the

point that Quasi-Newton calculation utilizes

appropriate headings for coming to the appropriate

response.

2. By expanding the engine speed to 3500 rpm, early

opening of admission valve causes improved

BSFC, and at 3500 rpm this pattern changes and at

4000 rpm a late opening of the admission valve

causes advanced BSFC, at that point up to 6000

rpm again the early opening of the admission valve

would be positive for improved BSFC.

Additionally, it is seen that the two calculations

aside from at 1500 and 6000 rpm would have a

similar answer.

V. IMPACT OF INTAKE VALVE CLOSING TIME

ON ENGINE EXECUTION AND EXHAUST

EMISSI-ONS IN A SI ENGINE

In this investigation, an uncommon variable valve control

instrument that can fluctuate consumption valve shutting

(IVC) time was outlined and produced. IVC time was

shifted in a scope of 38º crankshaft point (CA) after base

flawlessly focused (aBDC) to 78º CA aBDC. Fumes valve

opening and shutting time, admission valve opening time

and lift were not shifted [7]. A solitary barrel, four stroke,

SI engine was utilized for the trials. Contingent upon the

engine speed, brake torque, volumetric productivity,

particular fuel utilization (SFC) and fumes discharge

varieties were explored for various IVC time esteems. The

brake torque was expanded by 5.1% at low engine

velocities and it was expanded by 4.6% at high engine

speeds with variable admission valve time. SFC was

diminished by 5.3% and 2.9% at low and high engine

speeds, separately. Likewise, HC and CO discharges were

diminished at high engine speeds [13].

PROPOSED WORK:

It's been reviewed using several papers that instant

movement of valves is not possible using cams as it

happens in theoretical valve timing diagram. This implies

that a new system of mechanism is required to move further

to decrease the losses. The shaded region in the diagram

given below shows the differences between the actual and

theoretical valve timings. In order to decrease the

differences of actual and theoretical valve timing diagram,

here a system is proposed in which the valve mechanism

actuation can be controlled through automation, using

solenoid valves. Solenoids valves will be controlled using

sensors, which works on the basis of either the position of

the piston or crank/crank-shaft.

A sensor can be applied on crank shaft which will monitor

the piston positions and will help in actuating the inlet and

exhaust valves.

2018 International Conference on Automation and Computational Engineering (ICACE - 2018)

Amity University Greater Noida Campus, U. P., India, Oct 3-4, 2018.

23

Fig. 4 Shaded portion shows the difference in theoretical

and actual opening and closing of the valve. [Author]

CONCLUSION

On the basis of the review made in this paper is that there is

the need of change of technology for controlling valve

timings. The current mechanism of using the cam for

operating the valve is having huge differences between the

actual and theoretical valve timings.So, we conclude that

using automation on the basis of the position of the piston

or crank, sensed by the sensors.

REFERENCES

[1] Variable cam timing: consequences to automotive engine

control des-ign. MrdjanJankovicStephenW. Magner, Ford

Research Labor-atory, P.O. Box 2053, MD 2036 SRL,

Dearborn, MI 48121, USA

[2] Review and analysis of variable valve timing strategies-eight

ways to approach H Hong*, G B Parvate-Patil and B Gordon,

Department of Mechanical and Industrial Engine-ering,

Concordia University, Montreal, Quebec, Canada

[3] Study and the effects of ignition timing on gasoline engine

perfo-rmance and emissions J. Zareei& A. H. Kakaee Published

online: 25 April 2013. The Author(s) 2013. This article is

published with open access at SpringerLink.com

[4] Mathematical optimization of variable valve timing for

reducing fuel consumption of a SI engineH. Kakaee, M.

Keshavarz, A. Paykani, M. Keshavarz

[5] Effect of intake valve closing time on engine performance and

exhaust emissions in a spark ignition engine. Can ÇINAR,

Fazı l AKGÜN, Department of Mecha-nical Education, Faculty

of Techni-cal Education, Gazi University, 06500

Teknikokullar, ANKARA

[6] Tuttle, J. H. Controlling engine load by means of late intake-

valve closing, SAE Paper, No. 800794, 1980

[7] Golcu M, Sekmen Y, Salman MS (2005) Artificial neural-

networkbased modeling of variable valve-timing in a spark-

ignition engine.Applied Energy 81:187–197

[8] Chan SH, Zhu J (2001) Modeling. Int J ThermSci 40(1):94–103

[9] Chan SH, Zhu J (2001) Modeling of engine in-cylinder

thermos-dynamics under high values of ignition retard. Int J

ThermSci 40(1):94–103Dresner, T., Barkan, P., A Review and

Classification ofVariable Valve Timing Mechan-isms, SAE

Paper, No: 890674, 1989.

[10] S. Hsieh, A.G. Stefanopoulou, J.S. Freudenberg, K.R.Butts,

"Emission and Drivability Tradeoffs in a Variable Cam Timing

SI Engine with Electronic Throttle,"Proceedings of ACC ,

Albuquerque, NM, June 1997.

[11] Heisler, Advanced engine technology , SAE International,

Warendale, PA, 1995.

[12] R. Flierl, M. Kluting, "The Third Generation ofValvetrains -

New Fully Variable Valvetrains for Throttle-Free Load

Control," SAE Paper 2000-01-1227

ResearchGate has not been able to resolve any citations for this publication.

Introduction Ignition timing, in a spark ignition engine, is the process of setting the time that an ignition will occur in the combustion chamber (during the compression stroke) relative to piston position and crankshaft angular velocity. Setting the correct ignition timing is crucial in the performance and exhaust emissions of an engine.The objective of the present work is to evaluate whether variable ignition timing can be effect on exhaust emission and engine performance of an SI engine. Method For achieving this goal, at a speed of 3400 rpm, the ignition timing has been changed in the range of 41° BTDC to 10° ATDC and for optimize operation, ignition timing has been designed at wide-open throttle and at last, the performance characteristics such as power, torque, BMEP, volumetric efficiency and emissions are obtained and discussed. Results The results show optimal power and torque is achieved at 31°CA before top dead centre and volumetric efficiency, BMEP have increased with rising ignition timing. O2, CO2, CO has been almost constant, but HC with advance of ignition timing increased and the lowest amount NOx is obtained at 10 BTDC. Conclusions In conclusion, it obtained that ignition timing can be used as an alternative way for predicting the performance of internal combustion engines. Also engine speed and throttle position were all found to significantly influence performance in this engine.

Tradeoffs between low feedgas emissions and smooth brake torque are discussed in the context of an engine equipped with variable camshaft timing (VCT). The use of VCT lowers the generation of feedgas emissions but adversely affects the torque response. However, with the addition of an electronic throttle and knowledge of online torque, the tradeoffs between emissions and drivability in the VCT engine can be lessened; conventional (nonVCT) engine torque response can be achieved while simultaneously preserving most of the emissions benefits gained by using VCT

  • Hanyu Hong Hanyu Hong
  • G. B. Parvate-Patil
  • Brandon W. Gordon

In internal combustion engines, particularly for spark ignition (SI) engines, valve events and their timings have a major influence on the engine's overall efficiency and its exhaust emissions. Because the conventional SI engine has fixed timing and synchronization between the camshaft and crankshaft, a compromise results between engine efficiency, performance, and its maximum power. By using variable valve timing (VVT) technology it is possible to control the valve lift, phase, and valve timing at any point on the engine map, with the result of enhancing the overall engine performance. To get full benefits from VVT, various types of mechanisms have been proposed and designed. Some of these mechanisms are in production and have shown significant benefits in improving engine performance. During the last two decades, remarkable developments have been seen in the field of VVT. This paper reviews the literature in the technology of intake and exhaust philosophies of VVT and their effects on the pressure—volume (PV) cycle of the engine. A single-cylinder engine is simulated by the GT-Power software. The effects of different VVT philosophies from the simulations are analysed and compared to those of the literature reviewed.

  • S.H. Chan S.H. Chan
  • J. Zhu

This paper presents the work on a carburetted gasoline engine, in particular the complete modelling of an engine in-cylinder thermodynamics under high values of ignition retard (HVIR). The "combustion" is a two-zone burnt/unburned model with the fuel burning rate described by a Wiebe function. Under extreme spark timing retard conditions, the Wiebe function describing the heat release of the fuel–air reactions was modified to account for the critical change in pressure distribution in the cylinder due to the abnormal spark retard. An empirical correlation for cylinder pressure variation during the mass blowdown process, which occurs between the exhaust valve opened and bottom-dead-centre, was included in the simulation to enhance the predictive capability of the engine model. The complicated mass blowdown process across the exhaust valves was simplified by two processes: (i) isentropic expansion from the cylinder pressure to the constant exhaust manifold pressure, and (ii) constant pressure throttling which gives rise to increased exhaust gas temperature due to the recovery of kinetic energy.

  • H. Heisler

This book provides a comprehensive reference for anyone wanting to study the way in which modern vehicle engines work, and why they are designed as they are. The book covers virtually all configurations of commercially-produced engines, and features the latest engine technology including up-to-date coverage of electronic engine management and exhaust emission control. Chapters cover valves and camshafts; camshaft chain belt and gear train drives; engine balance and vibration; combustion chamber design and engine performance; induction and exhaust systems; supercharging systems; carburetted fuel systems; fuel injection systems; ignition systems; engine testing equipment; diesel in-line fuel injection pump systems; diesel rotary and unit injector fuel injection pump systems; emission control; cooling and lubrication systems; and alternative power units.

  • Stephen Magner

One objective of this paper is to illuminate fuel economy and emission improvement mechanisms of variable cam timing systems and analyze their effects on engine control system design. By retarding or advancing the cam phase one can vary the engine volumetric efficiency, as well as the amount of exhaust gas that dilutes the air charge. Combining these effects with intake manifold and engine speed dynamics leads to a complex behavior of engine air-charge and torque that requires special handling by the engine control system. This paper reviews control algorithms for VCT engines that have been reported in the literature.

Variable valve-timing and lift are significant operating and design parameters affecting the performance and emissions in spark-ignition (SI) engines. Previous investigations have demonstrated that improvements in engine performance can be accomplished if the valve timing is variable. Traditionally, valve timing has been designed to optimize operation at high engine-speed and wide-open throttle conditions. Controlling valve timing can improve the torque and power curve of a given engine. Variable valve-timing can be used to reduce fuel consumption and increase engine performance. Intake valve-opening timing was changed from 10° crankshaft angle (CA) to 30° CA for both advance and retard with 10° CA intervals to the original opening timing. In this study, artificial neural-networks (ANNs) are used to determine the effects of intake valve timing on the engine performance and fuel economy. Experimental studies were completed to obtain training and test data. Intake valve-timing and engine speed have been used as the input layer; engine torque and fuel consumption have been used as the output layer. For the torque testing data, root mean squared-error (RMSE), fraction of variance (R2) and mean absolute percentage error (MAPE) were found to be 0.9017%, 0.9920% and 7.2613%, respectively. Similarly, for the fuel consumption, RMSE, R2 and MAPE were 0.2860%, 0.9299% and 7.5448%, respectively. With these results, we believe that the ANN can be used for the prediction of engine performance as an appropriate method for spark-ignition (SI) engines.