Exam Question

### (a) Function of a Charge Air Cooler on a 2-Stroke Diesel Engine
The primary function of a Charge Air Cooler (or Intercooler) is to increase the density of the air supplied by the turbocharger to the engine cylinders. This is achieved by cooling the air after it has been compressed. The key functions and their consequences are:
1. **Increased Air Density and Mass Flow**: The turbocharger compresses air, which significantly increases its temperature (as per the Ideal Gas Law). The charge air cooler, a heat exchanger, cools this hot, compressed air. According to Charles's Law, for a given pressure, a decrease in temperature results in a decrease in volume. This leads to a substantial increase in the air's density ($$\rho = \frac{m}{V}$$). A denser charge means a greater mass of oxygen can be delivered to the cylinder during each scavenging period.
2. **Increased Power Output**: With a greater mass of oxygen available in the cylinder, a larger quantity of fuel can be injected and completely combusted per cycle. This results in a higher Mean Effective Pressure (MEP) and consequently, a significant increase in the engine's power output for a given cylinder volume.