Reciprocating Engine Induction Systems Flashcards
The 4 typical components of an induction system on a normally aspirated engine
- Air intake 2. Air filter 3. Fuel metering system 4. Induction manifold
The reason for why air-intakes/ air scoops are located in the propeller slip stream
The propeller slipstream has higher velocity that can be used for RAM air into the air scoops
The term for the ducting from the fuel metering device to the individual cylinders
description of the intake manifold
On some piston engines, the reason why the intake manifold would be routed through the oil sump before branching off into each cylinder
To increase the temp of the gas and make it easier to vaporize
The 3 forms of ice associated with an induction system on a piston engine
- Throttle 2. Fuel vapor icing 3. Impact
When visible moisture is striking an aircraft and then freezing
Definition of impact ice
The first indication of ice in the induction system
A reduction of engine power
Condition in a piston engine which will start off as a loss in engine speed followed by engine roughness ina fixed pitch propeller
Intake manifold icing
How intake manifold icing is first evidenced on a CONSTANT SPEED PROPELLER
Reduction in MAP with no change in engine speed
The system which ducts unfiltered air from within the engine cowling through a sheet metal shroud surrounding the exhaust pipe
Description of carburetor heat
The relationship between volumetric efficiency and carburetor heat
When carburetor heat is on, the air is less dense, the mixture becomes richer, and the volume of air displaced by the cylinder is reduced
The method that a super charger is typically driven by
Crankshaft via a gear train
The draw back of a super charger
The useage of large amounts of the engines power for the power increase
The method of which turbochargers are powered
Exhaust gasses from the engine used for compression purposes
Definition of Critical Altitude
Maximum altitude that a turbocharged engine can produce its rated horsepower under standard atmospheric conditions
The method by which turbocharger bearings are cooled
Engine oil in the turbocharger bearing housing
After air hot air leaves the turbo charger, the method of cooling the air before entering the cylinder to prevent _________
Intercooler, detonation
Times to switch on the carburetor heat
- Switch on when flying into known icing conditions 2. Switch on when ever there is a power reduction
The reason why carburetor heat should be switched on whenever there is a power reduction
With a reduction of throttle position and power, there is less hot air radiating from the engine to clear ice in the venturi
Difference between where Piper and Cessna aircraft get their carburetor heat from
Piper- warm air from behind the cylinder heads Cessna- warm air from the heat exchanger around the exhaust pipes
In a normally aspirated piston engine, the heater muff is essentially a_____ ______
heat exhanger
On carburetor engines, the location of the alternate air supply door
Alternate air supply door is located in the Carburetor air box
Identify parts
- Air filter
- Temperature probe
- Drain line
- Spring loaded Alternate air door
The type of piston engines which use alternate air doors
Fuel injection engines
What is this?
Carburetor Air box
Cessna or Piper?
Piper
Cessna or Piper?
Cessna
A supercharger can increase the engine’s volumetric effeciecny up to
100% volumetric efficiency
Where the MAP gauge SENSOR is located on all supercharged aircraft and why
Located just after the supercharger
Provides more accurate picture of engine performance
The downside of the early ground boost blowers (sea level superchargers)
The engine power output still decreased with an increase in altitude
The difference between internally driven super chargers and externally driven super chargers
Internal compress the fuel/air mixture
External compress the air
The 2 components of a cettrifugal compresseor
- Impeller
- Diffuser
The purpose of an impeller
To increase air velocity
The purpose of a difuser in a turbcharger
TO convert the kinitc energy of the air stream into pressure energy
The vanes in an impeller form what kind of shape
divergent
Since the turbochrger gets hot during operation, how is it cooled
Engine oil pumped through the bearing housing
The flow rate of oil going through the turbo charger bearing housing
5 gallons per minute
The two methods of reducing the density loss of due to adiabatic heating through the turbo charger
- Passing massflow through an intercooler
- Spraying the fuel/air mixture from the carbureator through the eye of the impeller to reduce temperature
Aircraft that have super chargers/ turbo chargers typically have what kind of propeller?
Constant speed
What gauge in the cockpit is used for the pilot to know how much pressure is inside the manifold on an engine using a turbo/ super charger?
Manifold Absolute pressure gauge
Pressure ratio of an impeller compresser turbo charger increases as
It’s speed increases
How does the impeller/ turbo charger compensate for the loss of density at altitude being that it must maintain a constant mass of air
The impeller rotates faster via the wastegate controller
What is the position of the wastegate controller at critical altitude and why?
Mostly Closed (not fully to prevent it from being stuck) to ensure more exhasut goes over the turbine to increase compresser speed to compenate for density loss at altitude
Waste gate contorllers can be controled_______ or _________
manually or automatically
What is the means of actuating the waste gate controller
Engine oil and spring
What are the 6 types of Waste gate actuator controllers
- Absolute pressure controller
- Pressure ratio controller
- Rate of change controller
- Differntial presure controller
- Density controller
- Variable pressure controller
The APC uses a _____ to sense compresser outlet pressure
aneroid capsule
Position that the APC places the wastegate at low power setting
Fully closed
The purpose of the Automatic pressure controller in a Turbo charger system
Maintain preset Manifold pressure
The type of contorller in a Turbocharging system which prevents bootstrapping at part throttle conditions
Differneital pressure control
Type of controller which senses and maintains pressure between the compresser outlet and the inlet mainfold on a turbocharged engine
Differnetial pressure controller
Type of contoller used to control waste gate operation when the throttle is fully opened and limits the maximum manifold pressure
Density pressure controller
The desnity controller in a turbo charged engine contains _____ gas which senses both the ______ and _____ of the compresser outlet air
nitrogen gas, temperture and pressure
Why does the density controller in a turbocharged engine increases the compresser outlet pressure
Reduction of pressure casued by an increase in temperature casused by the turbine and compresser having to work harder as the airraft climbs
The desnity controller in a turbo charged engine will ensure that the aircraft maximum avaible density will increase up to
critical altitude
The type of pressure contoller found on turbo charged aircraft which uses a cam that is linked to the throttle to control the engine bleed oil from the wastegate actuator
variable pressure controller
The pressure controller on a turbo charged engine which will govern MAP pressure when the throttle is opened rapidly
Rate of change pressure controller
Pressure controller used on a turbo charged engine which limits comrpesser deliviery( air charge temperature) at high altitude to prevent detonation
Pressure ratio controller
Wastegate actuators are spring loaded to the ______ position
fully open
Prior to engine start, what must the position of the waste gate actuator be in
Fully open
