Thesis (MScEng)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: This thesis is concerned with unsteady, one-dimensional flow, which closely
mimics those found in the manifolds of internal combustion engines. The physical
equations describing problems of this nature are presented and some of the
important concepts introduced. These equations and concepts were verified by
comparison to published results.
The Method of Characteristics (MaC) for unsteady one-dimensional flow with
friction and heat transfer was used to analyse the gas flow through the inlet and
exhaust systems of an engine. The theoretical derivation of unsteady gas
dynamic boundary conditions is presented and the integration with the unsteady
pipe flow explained.
A simulation flow model was developed to analyse the flow by using the Mae.
Thisflow model was then incorporated into an engine simulation program, ESA,to
simulate internal combustion engines and to predict the performance of a specific
engine. A cam-profile model and an in-cylinder thermodynamic model are used
to complete the ESAsoftware.
Experimental work was done on a modified Nissan Z24/NA20 engine to evaluate
the simulation model. The manifolds of the Nissan Z24/NA20 were modified to
isolate one of the cylinders for a proper single cylinder model. More
experimental work was done on a Volkswagen 1.6£ 8-valve and a 1.6£ 20-valve
engine to obtain performance data on two inlet manifolds developed using the
ESAsoftware.
Performance data and pressure traces in the inlet manifold of the Nissan
Z24/NA20 were recorded for comparison with the ESA software. Good
correspondence was found between tested and modelled data and the
differences varied between ±5% on engine performance data and pressure
wave frequency predictions, and ± 10% on pressure pulse amplitudes. / AFRIKAANSE OPSOMMING: Hierdie tesis handeloor bestendige, eendimensionele vloei, wat die gasvloei in
spruitstukke van binnebrandenjins naboots. Die nodige vergelykings wat hierdie
tipe probleme beskryf asook van die belangrikste konsepte, word bespreek.
Hierdie vergelykings en konsepte is met behulp van gepubliseerde data
geverifieer.
Die Metode van Karakteristieke (MVK) vir bestendige, eendimensionle vloei met
wrywing en warmte oordrag, is gebruik om die gasvloei deur inlaat en uitlaat
sisteme van 'n enjin te analiseer. Die teoretiese afleiding van bestendige
gasdinamiese randvoorwaardes asook hul integrasie met die bestendige
pypvloei, word verduidelik.
'n Simulasie vloeimodel is ontwikkelom die vloei met behulp van die metode van
karakteristieke te analiseer. Hierdie vloeimodel is deel van 'n omvattende
enjinsimulasie program, ESA. Dit word gebruik om binnebrandenjins te simuleer
en enjinwerkverrigting te voorspel. 'n Nokprofielmodel en 'n termodinamiese
ontbrandingsmodel word gebruik om die enjinsimulasie program af te rond.
Eksperimentele toetse op 'n gemodifiseerde Nissan Z24/NA20 enjin is gebruik om
die simulasie model te evalueer. Die spruitstukke van die Nissan Z24/NA20 is
aangepas om een van die silinders te isoleer om so 'n geskikte enkelsilindermodel
te skep. Verdere eksperimentele toetse is gedoen op Volkswagen 1.6£8-
klep en 1.6£ 20-klep enjins. Werkverrigtingsdata is verkry op twee nuwe
inlaatspruitstukke wat met behulp van die ESAsagteware ontwerp is.
Werkverrigtingsdata en drukverdelingsdata in die inlaatspruitstuk van die Nissan
Z24/NA20is aangeteken om te vergelyk met die resultate van die ESAsagteware.
Goeie ooreenstemming is verkry tussen toets- en gemoduleerde data. Die
verskille varieer tussen ±5% op enjin werkverrigtingsdata en drukpulsfrekwensie
voorspellings, en ± 10%op drukpuls-amplitudes.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/52343 |
| Date | 04 1900 |
| Creators | Van Vuuren, Christiaan Michael |
| Contributors | Thiart, G. D., Taylor, A. B., Stellenbosch University. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 1 v. (various pagings) : ill. |
| Rights | Stellenbosch University |
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