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Design and Simulation of Two Stroke Engines

Design and Simulation of Two Stroke Engines

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<strong>Design</strong> <strong>and</strong> <strong>Simulation</strong> <strong>of</strong> <strong>Two</strong>-<strong>Stroke</strong> <strong>Engines</strong><br />

1.1 The fundamental method <strong>of</strong> operation <strong>of</strong> a simple two-stroke engine<br />

The simple two-stroke engine is shown in Fig. 1.1, with the various phases <strong>of</strong> the filling<br />

<strong>and</strong> emptying <strong>of</strong> the cylinder illustrated in (a)-(d). The simplicity <strong>of</strong> the engine is obvious,<br />

with all <strong>of</strong> the processes controlled by the upper <strong>and</strong> lower edges <strong>of</strong> the piston. A photograph<br />

<strong>of</strong> a simple two-stroke engine is provided in Plate 1.5. It is actually a small chainsaw engine,<br />

giving some further explanation <strong>of</strong> its construction.<br />

In Fig. 1.1(a), above the piston, the trapped air <strong>and</strong> fuel charge is being ignited by the<br />

spark plug, producing a rapid rise in pressure <strong>and</strong> temperature which will drive the piston<br />

(A) COMPRESSION AND INDUCTION (B) BLOWDOVN EXHAUST PERIOD<br />

(C) FRESH CHARGE TRANSFER (D) APPRDACHING EXHAUST CLOSING<br />

Fig. 1.1 Various stages in the operation <strong>of</strong> the two-stroke cycle engine.<br />

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