What is the function of a diffuser in a supercharger?

The function of a diffuser in a supercharger is primarily to decrease the velocity of the charge while simultaneously increasing its pressure. As the air or gas passes through the diffuser, its cross-sectional area increases, allowing the kinetic energy of the fast-moving fluid to be converted into pressure energy. This process is crucial for efficiently channeling the charge into the engine's intake system, where higher pressure can enhance the engine's performance by allowing for a greater mass of air and fuel to enter, ultimately improving combustion efficiency and power output.

In terms of how this relates to engine performance, the ability to raise the pressure of the intake charge while reducing its velocity helps to ensure that the supercharger effectively boosts the engine's overall air intake, which is vital for achieving higher power levels, especially in performance applications. Thus, the correct answer emphasizes the relationship between pressure and fluid velocity in a supercharger setup, specifically through the function of the diffuser.