Superchargers & Turbochargers Flashcards
What is the difference between superchargers and turbochargers?
Superchargers are driven by the engine’s crankshaft, while turbochargers are driven by exhaust gases.
What is the function of a wastegate in a turbocharger?
It regulates the flow of exhaust gases to control turbocharger performance and prevent over-boosting.
What are the types of wastegates in turbochargers?
Fixed, cockpit-adjustable, throttle-operated, and automatic wastegates.
What is bootstrapping in turbochargers?
It occurs when the absolute pressure controller hunts for the desired manifold pressure at critical altitude.
What is the role of an intercooler in a turbocharged engine?
To cool compressed air before it enters the engine, improving efficiency and preventing detonation.
What are the advantages of superchargers?
Increased performance at lower altitudes and reduced takeoff distance.
What are the key terms related to superchargers?
Rated boost, manifold pressure, full throttle height, and critical altitude.
How does an automatic wastegate function?
It uses an absolute pressure controller to adjust the wastegate position and regulate manifold pressure.
What are the common faults in turbochargers?
Leaks, loss of pressure, and reduced engine performance.
What is the spring-loaded open position of a wastegate for?
To prevent over-boosting in case of oil pressure loss.
How can bootstrapping in a turbocharger be resolved?
By increasing RPM or decreasing altitude.
Why is forced induction necessary at higher altitudes?
To maintain engine power as air density decreases.
What is the difference between superchargers and turbochargers?
Superchargers are driven by the engine’s crankshaft, while turbochargers are driven by exhaust gases.
What is the function of a wastegate in a turbocharger?
It regulates the flow of exhaust gases to control turbocharger performance and prevent over-boosting.
What are the types of wastegates in turbochargers?
Fixed, cockpit-adjustable, throttle-operated, and automatic wastegates.
What is bootstrapping in turbochargers?
It occurs when the absolute pressure controller hunts for the desired manifold pressure at critical altitude.
What is the role of an intercooler in a turbocharged engine?
To cool compressed air before it enters the engine, improving efficiency and preventing detonation.
What are the advantages of superchargers?
Increased performance at lower altitudes and reduced takeoff distance.
What are the key terms related to superchargers?
Rated boost, manifold pressure, full throttle height, and critical altitude.
How does an automatic wastegate function?
It uses an absolute pressure controller to adjust the wastegate position and regulate manifold pressure.
What are the common faults in turbochargers?
Leaks, loss of pressure, and reduced engine performance.
What is the spring-loaded open position of a wastegate for?
To prevent over-boosting in case of oil pressure loss.
How can bootstrapping in a turbocharger be resolved?
By increasing RPM or decreasing altitude.
Why is forced induction necessary at higher altitudes?
To maintain engine power as air density decreases.
What is the function of idling jets in an aircraft engine?
They provide an air and fuel mixture when the throttle is closed.
What is the difference between internal and external supercharging?
Internal supercharging is part of the engine and doesn’t require a wastegate, while external uses turbochargers driven by exhaust gases.
What are the components of a turbocharging system?
Turbine, compressor, wastegate, and pressure controller.
How does the positioning of the carburetor affect engine performance?
Positioning it before the compressor reduces the risk of detonation.
What is the determining factor for engine power output?
Manifold pressure.
What is critical altitude in supercharged engines?
The altitude at which the supercharger can no longer maintain sea-level manifold pressure.
How is turbine RPM controlled in a turbocharged engine?
By the wastegate regulating exhaust gas flow.
Why is there a higher risk of detonation in supercharged engines?
Due to higher manifold pressures increasing air temperature and density.
What is the purpose of supercharging?
To increase mass airflow into the engine, enhancing performance.
What is the role of the impeller and diffuser in a compressor?
To increase air velocity and pressure.
What is the effect of leaks in the inlet system of a turbocharger?
Causes the wastegate to close earlier at lower altitudes or results in higher than normal manifold pressure at idle.
What is the effect of leaks before the wastegate and turbine in a turbocharger?
Exhaust gases escape, reducing airflow through the turbine and compressor, causing the wastegate to close earlier.
What is the effect of leaks after the turbine in a turbocharger?
No effect on manifold pressure.
What are the risks of a sticking wastegate in a turbocharger?
Can cause overboosting, jerky movements, and engine damage.
What happens during turbine blade failure in a turbocharger?
Can cause catastrophic engine failure due to high speed and temperature.
How can pilot error lead to overboosting?
Exceeding the rated boost or making sudden throttle movements can lead to detonation and engine damage.
What are the recommended practices to avoid overboosting?
Follow power settings in the POH, avoid exceeding the red line limit on manifold pressure, and make smooth throttle adjustments.
What is the difference in leak effects between turbochargers and superchargers?
Turbochargers can have leaks before or after the wastegate affecting manifold pressure, while superchargers lack an exhaust system and leaks after the compressor have no effect.
Why is regular inspection important for turbochargers and superchargers?
To identify leaks, sticking wastegates, and turbine blade issues before they cause significant damage.
What are common trick questions related to turbocharger leaks?
Leaks after the turbine have no effect on manifold pressure, and leaks at idle may cause higher than normal manifold pressure.
