What is the function and significance of piston aero-engine to control speed, intake and mixing ratio?

Throttle, that is, throttle valve, controls the intake air, and it is most important to control the output power of the engine by controlling the density of combustible mixture entering the cylinder.

By controlling the rotating speed through the propeller pitch control lever, the engine can be in the best working state and fuel can be saved. Assuming that the throttle is kept at the maximum and the speed of the aircraft is getting faster and faster, then the attack angle of the propeller blades relative to the airflow decreases and the engine speed increases-just like the speed of a car increases, but you keep the low gear-at this time, the pitch of the propeller is increased by manipulating the pitch lever, that is, the angle of the propeller blades relative to the airflow is increased, and the load of the propeller is increased to keep the engine at the optimal speed.

When the plane flies at high altitude, the air is thin and the concentration of mixed gas will become high, which will reduce the power and speed of the engine and emit black smoke. In severe cases, the engine vibrates and the exhaust pipe will be stuffy. At this time, the mixing rate should be reduced. On the other hand, if the mixing ratio is adjusted too low, the power and speed of the engine will be reduced, and the carburetor will backfire and shoot.