15.6.2 Factors which Increase the Power Output by Supercharging
The following factors are responsible for increased power output by supercharging:
Increase In power clue In Increase in Inlet pressure of the charge
The output of the supercharged engines is increased mainly due to the increased density of the
charge. This is obtained by increasing the inlet pressure of the charge. The pressure is increased by a compressor. After compression the temperature of the charge increases. As at high temperatures the density of the charge decreases, it is therefore essential to cool the charge in the after-cooler before it enters into the cylinder. This enables the cylinder to hold a comparatively denser charge, and hence the power output increases due to the effect of the after-cooler.
increase in power due to the additional filling of the engine cylinder
As the inlet pressure of the charge is increased, the pressure inside the engine cylinder increases. Due to this high pressure of the charge in the engine cylinder, the residual gases present in the clearance space are compressed. This facilitates the additional filling of the cylinder. Thus the density as well as the volume of the charge increases. Hence the power output is increased.