Question

__________ scavenging system has the highest efficiency.

(a) Loop or reverse

(b) Uniflow

(c) Cross

(d) None of the mentioned

The question was asked during an interview.

The query is from Scavenging Pumps topic in section Two Stroke Engines of IC Engine

Answer 1

Answer: (b) Uniflow

Explanation:

The Uniflow scavenging system is considered to have the highest efficiency among the various scavenging types in two-stroke engines. This is because, in a uniflow system, the fresh charge flows in a single direction, from one end of the cylinder to the other, ensuring that the exhaust gases are efficiently expelled without mixing with the incoming charge. This direct flow helps in achieving better scavenging efficiency and reduces the likelihood of unburnt fuel or incomplete scavenging, resulting in improved engine performance.

In contrast, loop and cross scavenging systems tend to have less efficient charge movement, with some of the fresh charge potentially being wasted or not fully utilized for expelling exhaust gases.

Therefore, the correct answer is (b) Uniflow.