Exam Question
Describe following terms with respect to Diesel Engine with suitable diagram:
(a) Natural aspiration (4)
(b) Scavenging (4)
(c) Supercharging (4)
(d) Types of Super charging in two stroke engine. (4)
Class 4 (4th Engineer)
MEKM
📅 Feb 2024
Reference Answer
### (a) Natural Aspiration
Natural aspiration refers to the process where an internal combustion engine draws in its combustion air solely by the pressure difference created by the downward movement of the piston within the cylinder, relying on atmospheric pressure without any external mechanical assistance or forced induction.
* **Concept:** The engine acts like a simple pump. As the piston moves downwards during the intake stroke (in a four-stroke engine), it creates a partial vacuum (lower pressure) inside the cylinder. The higher atmospheric pressure outside the engine then naturally pushes air into the cylinder through the open intake valve and manifold.
* **Mechanism:**
Natural aspiration refers to the process where an internal combustion engine draws in its combustion air solely by the pressure difference created by the downward movement of the piston within the cylinder, relying on atmospheric pressure without any external mechanical assistance or forced induction.
* **Concept:** The engine acts like a simple pump. As the piston moves downwards during the intake stroke (in a four-stroke engine), it creates a partial vacuum (lower pressure) inside the cylinder. The higher atmospheric pressure outside the engine then naturally pushes air into the cylinder through the open intake valve and manifold.
* **Mechanism:**
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