Module 4 Inductions Systems Flashcards
Density
Density is define as the mass of and object divided by its volume
Boyle’s law
For a given mass, at constant temperature, the pressure x volume = Constant ( temperature)
Relationship between pressure and volume ( temperature is a constant)
p V = C
Charles Law
If the temperature is creases the volume also increases in order to maintain the same constant (pressure)
V= C T
Density Altitude
Pressure altitude corrected for non-standard temperature variations
Aircraft fuel metering systems sensing?
The volume of air entering the engine
- no density
- not amount of oxygen
- not temperature
What effect would carb-heat have on the air/fuel mixture ?
- Carb-heat heats the air
- Heated air has less density
- The same volume of heated air will gave less oxygen than Colleen air
What happens when an aircraft climbs altitude?
- Mass of air will decrease with altitude, air becomes less dense
- The same volume of air at altitude will have less oxygen than air at sea-level
- Power reduction
Induction icing
- Throttle ice
- Fuel evaporating
- Impact ice
Consequents of impact Icing ?
- Power loss
- Enriches the mixture fuel/air
- Rough Running engine
Induction ice protection
- Intake ice filter
- Alternate Air
- Carb-heat
What is MAP and where is measured
Maximum absolute pressure mesures in the induction system before the throttle valve
Engine operation in a clear cool day may become critical if the relative humidity is high because of?
Carburetor icing
Carburetor pre heater is not generally used on take off because of?
- Loss power
- Rough running engine
- Detonation
If the carburetor air temperature is to high the probable result will be?
Loss power and detonation
Where is the “hot spot”
Oil sump
Two basic measurements that define standard day are?
29.92 HG and 15 Deg. C
How will an increase in carburetor air temperature effect the BMEP?
The heated air will decrease BMEP
What is Manifold Pressure?
Is the pressure in the intake manifold of the engine.
Weight of the fuel/air mixture entering the engine cylinders is measured by manifold pressure and the temperature of the mixture
What is the relationship between MAP and HP ?
Directly proportional, as manifold pressure increases, so does horse power
What are the two main purpose for turbo-charging?
- Maintain the sea-level horse Power to altitude
- Increase sea-level horse power
Critical altitude is ?
The maximum altitude which sea-level horsepower can be maintained
Boosted manifold pressure is any pressure above ?
-29.92 HG
Super chargers are ___________ driven blowers
Engine
Mechanical-gear or belt
Turbochargers are _______________ driven blowers?
Exhaust gas
Excessive manifold pressure will result in ?
Rise in temperature of the charge and result in detonation if not controlled
What is the difference between single stage- single speed supercharger; and single stage-two speed supercharger?
The speed of the blower can be changed on the single stage-tow speed supercharger for altitude operation
Where Turbochargers are located?
Between the air intake and the fuel metering device
What is upper deck pressure
Pressure after the blower but before throttle
What is the purpose of the intercooler?
To reduce the temperature of the fuel/air mixture
What are the 2 types of turbochargers systems ?
- Normalized - works at higher altitudes not sea-level ( compensate for loss power at altitude)
- Ground boosted-sea level up to critical altitude
What is the purpose of the waste-gate valve ?
Control the amount of exhaust gas to the turbo system
There is an oil flow restriction in the waste-Gate actuator, this restriction is located in the ?
Inlet of the waste-Gate actuator
Automatic waste gate control main parts ?
- Waste Gate actuator
- Absolute pressure controller
- Pressure Ratio Controller
- Rate of change controller
How waste actuator is controlled?
Spring pressure to open , oil pressure to close
Maximum altitude a turbocharged engine can produce its rated horsepower ?
Critical altitude
What is the upper pressure ?
From the compressor to the throttle
The absolute Pressure controller functions to limit?
The maximum upper deck pressure
To provide additional protection against an over boost condition many systems use a ?
Pressure relief valve
The rate of the change controller functions to?
Limit the upper deck pressure from 2.0 to 6.5 HG/SEC m, to reduce turbine acceleration overboost
The pressure controller setting is _______ times ambient pressure :
2.2 times ambient nacelle pressure
Proper operation of the ratio controller can be determined only by flying the aircraft through?
16.000 feet density altitude
The APC, rate of change and pressure ratio controllers, control de oil flow trough the waste gate actuator by sensing ?
Upper deck pressure
The APC( absolute pressure controller) rate of change and pressure ratio controllers are connected by ?
Parallel
The teledyne continental fuel injection pump uses and aneroid bellows to sense the upper deck pressure to prevent ?
An overly rich mixture upon rapid acceleration
Density controller vs APC
- Density controller- limit max MP
- sense density
-APC -limit Max MP- sense the pressure
Differential pressure controller vs VAPC
-Differential Pressure
Limits UDP to 6.5 “HG above the select MAP
Sense the UDP and MAP
-VAPC
Limits UDP to 2” Hg above selected MAP
Mechanical cam lobe to throttle setting
