12.theoretical and practical analysis of the in-cylinder tumble motion (1)

8/17/2019 12.Theoretical and Practical Analysis of the in-Cylinder Tumble Motion (1)

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Theoretical and Practical Analysis

of the in-Cylinder Tumble Motion

Dan Moldovanu and Adela Ioana Borzan

Abstract The present paper presents a comparative analysis of the in-cylinder tumble

motion of the fluid (and because it is a I!" the fluid is actually air mi#ed $ith

%asoline& usin% an e#istin% desi%n from a 'ols$a%en Polo en%ine (type A)*&" andintroducin% it to a C+D simulation soft$are (A', +I!&. The ob/ective of the paper is

first of all to compare the practical testbench measurements to the simulation resultsand see the differences. Then" modify the standard test-bench by mountin% a tumble

flaps and also modify the intae port an%le (lar%er $ith 0° and smaller $ith 0°& to seethe in-cylinder tumble movement and ali%nment. The e#istent controlled motions

inside the cylinder $ere presented" lie tumble" s$irl and s1uish" alon% $ith the

methods and $ays to analyze all these motions. There are more methods of analyzin%

the motion of the air inside the cylinder" lie usin% a cross-correlation di%ital Particle

Ima%e 'elocimetry (PI'& (non-intrusive" but most e#pensive&" or by usin% a paddle$heel mounted inside the cylinder (hi%hly intrusive" lo$ cost&" or by mountin% an

anemometer inside the cylinder (moderately intrusive but the in fluence is the same for all measurements—systematic error" lo$ cost&" and the most e1uilibrated from theindication precision2cost point of vie$" a point-lie built anemometer (lo$

intrusiveness and lo$ cost&.

3ey$ords Tumble Practical testbench Theoretical comparison A', +I!

Introduction

There are many papers that studied the effects of in-cylinder motion of the air2mi#ture"

lie (Badami et al. 45567 8e et al. 459:7 ,an%rish et al. 4556&" but many use C+D"

because in a prototypin% phase" C+D offers many advanta%es" such as lo$ simulation

time in comparison to measurements" lo$er costs" and the opportunity to better

optimization (;ai$ad et al. 455apoca" Clu/->apoca" omaniae-mail? [email protected]/.ro

© prin%er International Publishin% $itzerland 459C. Andreescu and A. Clenci (eds.&" Proceedings of the European Automotive Congress EAEC-ESFA 2!"" DI 95.9552


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+i%. 4 'alve openin%

ad/ustment mechanism

After importin% the surface in A', +I!" the ed%e mesh $as built" and the

dimensions for the cells $ere chosen" so that the final mesh is as fine as possible but$ith minimum build time (if the build time is small" the simulation time is also


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ection

I

II

III

I'

I

II

III

I'

I

II

III

I'

I

II

III

I'

+i%. 0 Tumble motion comparison for different valve openin%s. a 'alve openin% at :.0 mm. b

'alve openin% at mm


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55 D. Moldovanu and A.I. Borzan

+i%. The intae pipe comparison. a eal intae pipe. b 'irtual intae pipe

+i%. Intae model (! cylinder liner" 2 cylinderhead part of the intae" intae pipe&

Theoretical and Practical Analysis of the in-Cylinder Tumble %

+i%. The mesh and ed%e mesh of the model. a Mesh. b !d%e mesh


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+i%. < tandard intae port (' G :0°& and comparison versions at ' G 65° and 60°


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54 D. Moldovanu and A.I. Borzan

+i%. 95 Tumble analysis for the three versions of the intae pipe

esults and Discussions

The results of the simulation are presented in +i%. 95. The representations sho$ the

influence of the an%le of the intae pipe on the tumble motion inside the cylinder.

Conclusions

+rom the simulations" $hen modifyin% the an%le of the intae port the center of

the in-cylinder tumble motion chan%es" if the an%le is smaller $ith 0 °" the center moves a$ay from the center of the cylinder" $here the spar plu% is mounted" and

if the an%le is $ith 0° bi%%er" the center moves more to$ards the center of thecylinder but still a$ay from the spar plu%.

In conclusion" the tumble coef ficient can be modified by mountin% a tumbleflaps" and the position of the center of the in-cylinder tumble motion can be con-trolled by modifyin% the an%le of the intae pipe or (a method that $as not tested&

by havin% a profiled piston" to$ards the spar plu%.This paper sho$s the ti%ht bond bet$een simulation and real measurements

made on a testbench.The authors" previously studied s$irl motion inside a CI!" $ith the paper?

Computational fluid dynamics simulation of a sin%le cylinder research en%ine$orin% $ith biodiesel" published at Thermal cience.


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Theoretical and Practical Analysis of the in-Cylinder Tumble %

Acno$led%ments This paper $as possible $ith the unconditioned help of !n%. Balea Bo%dan

Aurel and !n%. Bordas ,orant-Tibor.

eferences

Badami M" Bevilac1ua '" Millo +" Chiodi M et al (4556& ;DI s$irl in/ector spray simulation? a

combined phenomenolo%ical-C+D approach. A! Technical Paper 4556-59-:550. doi?95.

64924556-59-:550

;ai$ad et al (455

12.theoretical and practical analysis of the in-cylinder tumble motion (1)

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