Aircraft engine power is measured according to its performance capabilities in ideal conditions known as ‘standard day’ conditions. When an aircraft engine has 300 horsepower, it means the engine has 300 horsepower in standard day conditions. However, standard day only refers to conditions at sea level. As you would guess, conditions at higher elevations deviate significantly from standard day. Air pressure, barometric pressure, and air temperature are wildly different at 20,000 feet than they are on the ground - pressure, for instance, is roughly half. Because of this, a normally aspirated engine will also perform at just half its usual power. This is where turbochargers come in.
Turbochargers are capable of replicating standard day conditions at much higher altitudes, allowing the engine to perform as if it were in more ideal conditions. The amount of air consumed by the engine compared to the theoretical volume of air in the atmosphere is called volumetric efficiency. By themselves, common piston engines have a very low volumetric efficiency. The purpose of the turbocharger is to increase the volumetric efficiency of the engine, usually by increasing the density of intake air.
The turbocharger operates by drawing in ambient air and subsequently compressing it before it enters the intake manifold at a higher pressure. This allows more air to enter the cylinders with each piston stroke. To regulate airflow, turbochargers employ a variety of controllers including variable absolute pressure controllers, absolute pressure controllers, density controllers, pressure relief valves, and more.
To ensure reliability and prolong the service life of a turbocharger, regular preventative maintenance is a necessity. They are subject to temperatures greater than 1600 degrees Fahrenheit and turbine wheels rotate at over 90,000 RPM. Turbine and compression blades must be analyzed for cracks or damage as well as drag or rubbing against the housing. Other factors such as oil contamination, foreign object debris, and oil supply issues are the most prevalent reasons for turbocharger failure, so regular checkups are a must.
At ASAP Logistic Solutions, owned and operated by ASAP Semiconductor, we can help you find all the turbocharger parts for the aerospace, civil aviation, and defense industries.