Aircraft Powerplant Assessment 30 questions

Absolute Pressure

 

Sum of the gauge pressure and atmospheric pressure.

Boundary

Separates the substance to its surroundings.

Every body persists in its state of rest, or of motion in a straight line, unless acted upon by some outside force

Newton’s first law of motion generally termed the law of Inertia. States:

Brayton Cycle

A turbojet engine operates on a?

an isentropic process

Entropy is also defined as that function of the working substance which remain constant during:

Stroke

It is referred to as the distance the piston travels from its outward limit.

53.5

A certain spring when stretched measures 15.5 cm requiring a work of 564 joules to do it. Its free length is 5.4 cm. What is the spring constant (in kN/meter)?

Torque bending force

A type of force that occurs as air resistance opposes the rotational motion of the propeller's blades. This force tends to bend the blades opposite the direction of rotation.

Diesel Cycle

A four stroke cycle engine in which air only is taken into the cylinder on the suction stroke and liquid fuel is lower injected. No spark plug used. High temperature due to high Compression. Constant pressure combustion.

Pressure

In the P-V diagram of the Brayton Cycle, which parameter is constant?

centrifugal and axial flow

The two types of compressor commonly used on jet engines are

converted into another

The first law of thermodynamics states that one form of energy may be?

the less tendency of gasoline to detonate

The detonation properties of gasoline are measured by an octane number, the higher the number,

N2 Compressor

In a dual axial-flow compressor, the first stage turbine drives__________.

0.01 cu m

The temperature of an ideal gas remains constant while the absolute pressure changes from 103.4 kPa to 827.2 kPa. If the initial volume is 80 liters, what is the final volume?

It increases the surface area of the cylinder for convection.

How do cooling fins help in dissipating heat from the cylinder assembly?

Opposed

The _____ type engine has two banks of cylinders directly opposite each other with a crankshaft in the middle.

As a fail-safe in case one of the springs fail.

Why is it preferred to have two sets of valve springs?

Boyle's Law

This shows the relationship of the pressure, volume, temperature and mass of a gas in reference to its universal gas constant.

203

In a certain location, the barometer reads 13.45 psi and a pressure gauge reads 86 psig. Solve for the absolute pressure in inches mercury.

Crankpin

These are offset from the main bearing journal to provide attachment points for connecting rods.

Front of the compressor and the aft end of the turbine.

Engine pressure ratio is the total pressure ratio between the

Volume

Which of the following is not an intensive property?

287.08 J/kg-K

Universal gas constant is equal to __________.

Connecting Rod

The _____ is the link which transmits forces between the piston and the crankshaft.

blue

100LL aviation fuel is colored

Bypass ratio

It is the ratio of the mass of secondary air to the mass of primary air

Complete 2 strokes

A crankshaft completes one rotation in order to:

mineral or synthetic based.

The recommended aircraft engine lubricants are

9,996

Calculate the pressure (in kPa) at the start of power stroke of an internal combustion engine, assuming the specific heats and gas constant for the fuel-air mixture are approximated by the air values alone. The temperature at the start of the power stroke is 3490 deg K. The temperature at the end of the compression stroke is 550 deg K. and the pressure at the end of the compression stroke is 15.5 atm.