The power increase that occurs with initial increase in altitude when an engine has an internal supercharger is due to what?

When considering the operation of an engine equipped with an internal supercharger at higher altitudes, the power increase initially observed is primarily influenced by the characteristics of the supercharger and how it interacts with the atmospheric conditions present at altitude.

An internal supercharger functions by compressing the intake air before it enters the combustion chamber, thereby enhancing the engine's overall efficiency and power output. As altitude increases, the atmospheric pressure decreases, which typically results in lower air density. However, at the initial stages of climbing altitude, the internal supercharger can effectively compensate for some of this loss in air density by providing a richer charge—higher mass flow of air into the combustion chamber—because it actively compresses the intake air.

The reduction in exhaust back pressure plays a lesser role in this scenario. While lower altitude does result in higher atmospheric pressure and thus higher exhaust flow efficiency, the supercharger's contribution to power output is more significant than exhaust pressure considerations during the initial climb.

Ultimately, the internal supercharger allows the engine to harness the reduced weight of the intake mixture efficiently, but the fundamental mechanism enabling increased power at altitude is tied to the enhanced charge density provided by the supercharger, offsetting the adverse effects of lower atmospheric density. This clarifies why the