Reciprocating Engine Induction and Cooling Systems Flashcards
What does a fuel-injected engine have that prevents the loss of induction air if the air inlet filter should become covered with ice?
An alternating air valve allows warm air from inside the engine cowling to flow into the fuel metering system
What would be the effect on engine operation of an air leak in the intake pipe for one cylinder?
That cylinder would run lean and detonation could occur
What must be inspected on the cooling system of an air-cooled engine?
All of the baffles and air seals must be in place and in good condition
Why should an air-cooled engine not be run up to high power without the cowling installed?
The engine depends on the cowling to force air through the cylinder fins to remove the excess heat
Why do some air-cooled engine installations have cowl flaps?
Cowl flaps produce a low pressure on one side of the engine to pull air through the cooling fins on the cylinders
What document describes the proper use of cowl flaps on an air-cooled engine?
The pilot’s operating handbook
What is the relationship between the turbine engine upper temperature limits and power produced?
The higher the combustion temperatures that an engine can withstand without damage, the more power it is capable of producing.
What is the approximate percentage of air passing through a turbine engine that issued for cooling rather than combustion?
Approximately 75%.
What can be done to effectively allow higher gas temperatures in the turbine section of some engines?
Compressor bleed air and first stage rotor blades can lower temperatures enough to prevent heat damage
Compressor bleed air ducted through hollow sections in the turbine inlet guide vanes and first stage rotor blades can lower temperatures enough to prevent heat damage.
What effect does excessive heat have on reciprocating engines?
- It shortens the life of the engine parts
- Change the behavior of combustion
- Impairs lubrication
What is the purpose of cooling fins?
They remove heat from the cylinder heads
They provide a larger cooling surface area for removing heat from cylinder heads of air-cooled reciprocating engines.Airflow around the cooling fins transfers the heat from the cylinder heads to the air.
What are the reasons for using engine cowlings, baffles and cowl air seals?
The cowling performs two main functions: it streamlines the engine area to reduce drag, and is used together with the baffles and cowl air seals to direct airflow over the cylinders for cooling.
What is the purpose of cowl flaps and how are they operated?
They are used to control the amount of airflow through the cowling. They are either mechanically, electrically or hydraulically operated.
How does an augmenter cooling system work?
An outer tube placed over the exiting exhaust gas creates a venturi effect that draws more airflow over the engine, thus providing additional cooling.
Where should cowl flaps be positioned for ground operations?
Fully open.
What type of power is used to operate cowl flaps?
Manual, hydraulic, or electrical.
What should be done when cooling fin damage is discovered?
Repair according to the manufacturer’s overhaul and repair limitations or replace if too much of the cooling fin is broken off
Depending on the scope of damage, some cooling fins may be repaired subject to the manufacturer’s overhaul and repair limitations. If an excessive amount of the cooling fin is broken off, the cylinder should be replaced.
