|Author: || G. P. Blair, S. J. Magee |
|Title: ||Non-Isentropic Analysis of Varying Area Flow in Engine Ducting |
|Date: || September 13-16 1993 |
|Published:|| SAE International Off-Highway and Power-plant Congress - Milwaukee, Wisconsin - SAE 932399 |
In two previous papers to this Society, an 'Alternative' method was presented for the prediction of the
unsteady gas flow behavior through a reciprocating internal combustion engine. The computational procedures
led further to the prediction of the overall performance characteristics of the power unit, be it operating
on a two or a four-stroke cycle. Correlation with measurements was given to illustrate its effectiveness
In the ducts of such engines there are inevitably sectional changes of area, which are either gradual or
sudden. A tapered pipe is typical of a gradual area change whereas a throttle or a turbocharger nozzle
represents a sudden area change. In those previous papers it was indicated that a fuller explanation, of
the theoretical procedures required to predict accurately the unsteady gas flow in such duct sections would
be given in a later paper to the Society; this is that necessary publication.
The theory of gradual and sudden area changes is presented, together with computational illustrations of its
application to real geometrical cases. The theory includes non-isentropic effects at such area changes and
inherently solves the mass continuity, energy and momentum equations at each section.
You may obtain a copy of this paper by calling SAE Customer Service at 1-877-606-7323 (toll-free in the U.S. and Canada) or 1-724-776-4970.