الفهرس Only 14 pages are availabe for public view
 |  | from | 215 |  |  |
| | | from | 215 | | |
Abstract
The present research work deals with the pressure waves caused by the non-steady flow of the exhaust system in internal combustion engines, and the effect of different parameters on the behavior of these waves and its effect on engine performance.
A theoretical investigation 0 f t he exhaust system in a four-stroke single cylinder diesel engine is given; the study includes the thermal cycle of the engine and the variation in pressure and temperature inside the engine cylinder together with the velocity of flow through the exhaust pipe to deduce the preliminary form of the pressure waves through the exhaust pipe.
Then a theoretical investigation of different numerical solutions for the non-steady state flow and their application to the exhaust system of internal combustion engines was carried out and numerical model was developed depending on the Benson methodology in which the entropy in the exhaust pipe was assumed to be uniform and constant ”Homentropic flow Field”.
The research work includes an experimental work on a test diesel engine to record the pressure wave patterns and amplitudes in the exhaust pipe at three positions.
Position” A”: Just after the exhaust valve.
Position ”B”: In the middle of the exhaust pipe.
Position ”C’: Near the end of the exhaust pipe.
The pressure waves were recorded through a strain gauge absolute pressure transducer with built in amplifier attached to digital oscilloscope connected to a plotter, under the following conditions:
1- Engine motoring test without fuel injection to simulate the non - steady flow without change in entropy ”homentropic flow”.
2- Engine firing test under different working conditions of load and r.p.m.
A comparison between the experiments and the numerical model results showed reasonable agreement.