CDF Project

7/25/2019 CDF Project

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PRESENTATIONON

Experime

ntalvalidation

and

emissiontestofcombust

ion

withC!mode

llin"of

CIen"inefuel

led with

biodiesel

#$ sachin %&


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Introduction Components of CI En"ine Combustion in CI En"ines 'ITERAT(RE S(R)E*

Case description Solver settin"s+ Computational Procedure RES('TS AN! !ISC(SSIONS+ Advanta"es,limitations,applications+

Conclusion References

Contents


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Introduction

Compression I"nition En"ines

A diesel en"ineis an internal combustion engine thatuses the heat of compression to initiate ignition to burn.

the fuelthat has been injected into thecombustion chamber.

The engine was developed by German inventor RudolfDiesel in 1!".

high temperatures and pressures in the combustionchamber cause a #ame.Diesel engines re$uire fuel injection systems to injectfuel into the combustion chamber
http://en.wikipedia.org/wiki/Diesel_fuelhttp://en.wikipedia.org/wiki/Combustion_chamberhttp://en.wikipedia.org/wiki/Combustion_chamberhttp://en.wikipedia.org/wiki/Diesel_fuel


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Components of CI En"ine

%ylinder headThe space at the combustion chamber top isformed and sealed by a cylinder head.

The cylinder head of a four&stro'e enginehouses inta'e and e(haust valves) the fuelinjection valve) air starting vale) safety valve.


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Components of CI En"ine*iston+t is one of the major moving parts of anengine.+t must be designed to withstand e(treme heatand combustion pressure.

+t is made of cast iron or aluminium ,to reduceweight-.


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Components of CI En"ine*istonrod +t connects the piston with the

crosshead.%rosshead The crosshead pin connects thepiston rod to the connecting rod.

%onnecting rod +t is /tted between the

crosshead and the cran'shaft. +t transmits the/ring force) and together with the cran'shaftconverts the reciprocating motion to a rotarymotion.


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%ombustion in a %+ engine is a non steadyprocess where a non homogeneousmi(ture is controlled through fuel

injection.The mi(ture is non homogeneous since airis the only substance being compresseduntil late in the compression stro'e.

+njection of the fuel occurs at about 10bTD% and ends at about 0 aTD%.

Combustion in CI En"ines


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The steps that the fuel goes through) afterinjection) in order to cause the proper

combustion.

Atomi2ation 3apori2ation 4i(ing 5elf&ignition


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our-stro&e C I en"ine valvetimin"


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P-) !ia"ram of a dieselen"ine


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Sundaram Arvin Ar$an et al+, The biodiesel e(tracted from rubber seeds ,Heavea braziliensis- can be

used as a fractional substitute for diesel fuel. A blend of /ve percent biodiesel ,66D0- by volume of diesel can be used to

diesel engines providing e7ective performance) reduced emissions and ithas a neutral e7ect on lubricating oil.

R+ .i&alsen et alThis paper investigates the in&cylinder gas motion) combustion process and

nitrogen o(ide formation in a free&piston diesel engine and compares theresults to those of a conventional engine) using a computational #uiddynamics engine model

increased ignition delays were found in the free&piston engine due to a lowercompression ratio at the start of fuel injection. A slight fuel e8ciency advantage was found for the free&piston engine)

which is consistent with earlier /ndings.

'ITERAT(RE S(R)E*


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.+ 'o"anathan et al+,

+n this study) 6iodiesel &Dimethyl 9ther ,6D9 - was tested in a

:&cylinder direct&injection diesel engine.

The 6D91; blends have 1;< higher bra'e thermal e8ciency,6T9- .The e(perimental results showed that the %=) >% and?=( emission is decreased for all 6D9 blends.

Thirunavu&&arasu /ANAPAT0* et al+ 123+

+n the present wor') a thermodynamic model has beendeveloped to study the performance characteristics of the

@atropha biodiesel engine.

it is concluded that the two 2one thermodynamic model can beused to predict the performance characteristics of the @atrophabiodiesel fueled diesel engine.


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To conduct an e(periment on combustion of%+ engine using biodiesel e(tracted fromdiary scum.

3alidation of e(perimental results using %Dsoftware

To prove that bio&diesel is a suitablereplacement for diesel.

Aim of the pro%ect


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O#4ECTI)E

The primary objectives of the project are To analy2e the combustion temperature

pro/le.

To determine the performance parameters. To determine the emission parameters.

To analy2e the 4eshed model using luent

%D software.


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The model used for the analysis is drawn in deign modellerand meshed in the same ansys software) which is thecompatible modelling software for BC9?T. All the /les forthe geometry and meshing of the model are saved as mesh

or grid /le. ?e(t) in BC9?T) the saved mesh or grid /le of the model is

read) chec'ed and scaled for the re$uired wor'ing unit. The model is de/ned for the type of solver and boundary

conditions to be used. The model is de/ned according to

the type of analysis re$uired in the research project. The model is solved by setting the re$uired parameters in

the solution panel and then iterated for convergence.

The procedure for the C! anal$sis in '(ENT followsthe simple steps below5

10


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Results can be obtained from the graphicdisplay and report in BC9?T.

Results can be displayed in terms ofcontour) velocity vector) and particle trac'and path line.

Any calculation re$uired can be performedin BC9?T also. inally) the results and all the data can be

saved for future references by writing the

/les.

1


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.odelin" 6"overnin" e7uations8 ?avier&5to'es e$uations ,"D in %artesian coordinates-

+

+

+

=

+

+

+

2

2

2

2

2

2

z

w

y

w

x

w

z

p

z

w

wy

w

vx

w

ut

w

1E

+

+

+

=

+

+

+

2

2

2

2

2

2

z

u

y

u

x

u

x

p

z

u

wy

u

vx

u

ut

u

+

+

+

=

+

+

+

2

2

2

2

2

2

z

v

y

v

x

v

y

p

z

vw

y

vv

x

vu

t

v

( ) ( ) ( )0=

+

+

+

z

w

y

v

x

u

t

RTp =

L

v pp

Dt

DR

Dt

RDR

=+

2

2

2

)(2

3

%onvection *ie2ometric pressuregradient

3iscous termsBocalacceleration

%ontinuity e$uation

9$uation of state

Rayleigh 9$uation


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6oundary conditions

ollowing are the assumptions incurred onthe present analysis

low is Turbulent low is Transient and incompressible 5egregated solver

Case description


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5olver& 5egregated ormulation&+mplicit *ressure discreti2ation&5tandard

4omentum discreti2ation&5econd orderupwindTurbulent 'inetic energy&irst order upwind 5peci/c dissipation rate ,omega-&irst order

upwind *ressure&3elocity coupling&5+4*B9

Solver settin"s+


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The iterative process is repeated until thechange in the variable from one iteration tothe ne(t becomes so small that the solutioncan be considered converged.

At convergence All discrete conservation e$uations ,momentum)

energy) etc.- are obeyed in all cells to a speci/edtolerance.

The solution no longer changes with additionaliterations.

4ass) momentum) energy and scalarbalances are obtained

Conver"ence Criteria


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The #ow domain considered for simulation isdownstream .

Therefore) #ow through inta'e manifold is notmodelled.

The engine operating at rated speed ,10;;revFmin-.

inta'e and e(haust valve movement is simulatedusing the actual valve lift pro/le of the engine.

The computations commence with the inductionprocess.

#oundar$ and InitialConditions


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+nitial conditions are pressure of !; 'pa.

temperature of ";; H .The three components of velocity are ta'en as

;.;;1 mFs. turbulence 'inetic energy and dissipation rate are

assumed at ;.;;1 m

Fs

and ;.;;1 m

Fs"

respectively.


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%omputations have been made for an operational speed of10;; revFmin) with time step of the order of ;.0I %A ,0 microseconds-.

The inta'e valve closes at !I a6D% ,after 6ottom Dead %entre- at which time the boundary condition at the inta'e valve is

changed from JpressureK to JwallK to prevent #uid escaping fromthe cylinder.

upward movement of the piston results in compression of the#uid till the piston reaches TD%) beyond which #uid e(pansionoccurs

The e(haust port opens at "!I 66% ,6efore 6ottom %entre- byintroducing a pressure boundary condition at the e(haust port

The e(haust process continues till the piston reaches T%) whichcompletes one cycle of operation.

Computational Procedure


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Results from the modelling and %Dsimulation using BC9?T software areshown and discussed. Results are shown interms of graphs for the simulation results

for pressure distribution) temperaturedistribution and 3elocity.

RES('TS AN! !ISC(SSIONS


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Pressure contours at di9erent cran& an"le

Pressure contours at different crank angle


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Pressure contours at different crank angle


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As the piston move towards TD% there will be a rise inpressure and reaches ma(imum of 0: bars


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Temperature contours at di9erent cran& an"le


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Temperature contours at di9erent cran& an"le


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Temperature contours atdi9erent cran& an"le


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)elocit$ contours at di9erentcran& an"le


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)elocit$ contours at 2di9erentcran& an"le


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The engine speci/cation and other inputs areprovided as follows

+3% L "" %AT+3%L :;:.:!1 H *+3%L ::; *aTcylinderL 0E H

TheadL ; HTpistonL :0 H 5wirl Ratio+3% L 1.

Combustion Anal$sis


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Discharge %oe8cient L ;.ETotal 4ass 5prayed L ;." g 5=+ L ".1 %A , deg after TD%- and "

+njection Duration L 0 degree

Other in%ection speci:c inputs are as follows5


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Transient Temperature Contours


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The Advantages of CFD


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%D gives a means of visuali2ing andenhanced understanding of your designs.

%D helps engineers and designers todesign better and faster.

Time and money are saved. *roducts get tomar'et faster.

The Advantages of CFD

E

i i i f


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The input data may involve too much guesswor' or imprecision

The available computer power may be toosmall for high numerical accuracy ,in terms of

the memory spaces and capabilities-The scienti/c 'nowledge base may be

inade$uate +n terms of the reliability) %D software

di7erentiates itself with the following aspects or laminar #ows rather than turbulent ones

'imitations of C!

E!

Applications of CFD


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5imultaneous #ow of heat) 4ass transfer ,eg. perspiration) dissolution-) *hase change ,eg. melting) free2ing)

boiling-) %hemical reaction ,eg. combustion) rusting-) 4echanical movement ,eg. of pistons) fans)

rudders-

5tresses in and displacement of immersedor surrounding solids.

Applications of CFD

;

l i


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o A good agreement between the modelingand e(perimental data needs to be ensured.

o Mor' is being carried out to show that %Dcan be a reliable tool for the combustionmodelling of %+ engine fueled with biodieselblend. Also biodiesel ,diary scum blend- canbe a suitable replacement to diesel) hence itcan be used as a alternative fuel for a futurewor'.

1

conclusion

REERENCES


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N.Ta'ena'a) 4.Nabe) N. Aoyagi and T. 5hio2a'i ,1!!;- hasstudied OThree dimensional computation of +n&cylinder lowwith inta'e port in D+ Diesel 9ngineP.

5emin) Rosli Abu 6a'ar and Abdul Rahim +smail ,;;- hasstudiedP%omputational 3isuali2ation and 5imulation of Diesel

9ngines 3alve Bift *erformance Csing %DP. @. 6enajes.Q1!!;O?umerical solution of #ow and combustionin an a( symmetric internal combustion engineP.

Gosman and >arveyhas studied O?umerical solution of #owand combustion in an a( symmetric internal combustionengineP.

6enny *aul1 low /eld development in a direct injectiondiesel engine with di7erentmanifolds. +nternational journal ofengineering) science and technology)3ol..?o.1);1;.

REERENCES

Alemayehu Gashaw and Amanu Ba'achew. O*roduction of


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6iodiesel rom ?on 9dible =il and its *ropertiesP)+nternational @ournal of 5cience) 9nvironment and

Technology) 3ol. ") ?o :) ;1:) 10:: S 10.

5undaram Arvin Aryan and 5utra 5hebang. O%haracteristicsand Thermal 98ciency of 6efouls Rubber 5eed =il as aRenewable 9nergy 5ourceP. +nternational @ournal of 5cienceand 4odern 9ngineering ,+@+549- +55? "1!&") 3olume&1) +ssue&) 4ay ;1".

?orseman 3) @eya'umar 5) 4ani 4 and Guttu =fgaa. O97ectof ?eat 5ardine =il with 3aries 6lends on the *erformanceand 9mission %haracteristics of Diesel 9ngineP. 5cience)

Technology and Arts Research @ournal) ;1) 1,:-0&:. Ambarish Datta and 6ijan Humar 4andal. O6iodiesel

*roduction and its 9missions and *erformanceP.+nternational @ournal of 5cienti/c 9ngineeringResearch)3olume ") +ssue ) @une&;1) +55? !&001.

"

Transient Temperature Contours


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CDF Project