Hanseo university – Air transfortation & logistics department - Aeronautical and Space Sciences

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REPORT Department: Air transfortation & logistics department

Class: Aeronautical and Space Sciences

Name: Enkhjin Davaanyam

Student number: 201501784

2015.12.03

Hanseo university – Air transfortation & logistics department - Aeronautical and Space Sciences

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1. Solid rocket and liquid rocket of the hybrid rocket engine, explain the advantages

and disadvantages (5.4)

2. Explain the working principle of the 4-stroke reciprocating engine (5.9)

3. Explain the difference between the Strapdown technologies and Platform system

of Intertial Navigation(INS) system technologies (6.4)

4. Explain the principles and the type of the Flight data recorder (FDR). (6.9)

5. Explain the principles of a Pitot static system and describe operation of the

instrument using this system (7.4)

6. Describe the using of DC motor in the aircraft (7.9)

Hanseo university – Air transfortation & logistics department - Aeronautical and Space Sciences

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Solid rocket and liquid rocket of the hybrid rocket engine, explain the respective

advantages and disadvantages. (5.4)

A hybrid rocket is a rocket with a rocket motor which uses rocket propellants in two different

phases. Hybrid rockets exhibit advantages over both liquid rockets and solid rockets especially

in terms of simplicity, safety, and cost.

1. Liquid rocket

A liquid (propellant) rocket or liquid rocket is a rocket engine that uses liquid propellants.

Liquids are desirable because their reasonably high density allows the volume of the propellant

tanks to be relatively low and it is possible to use lightweight centrifugal turbo pumps to pump

the propellant from the tanks into the combustion chamber.

o Engine cycles

For liquid-propellant rockets four different ways of powering the injection of the propellant into

the chamber are in common use.

Pressure fed cycle – The propellants are

forced in from pressurised tanks. The

heavy tanks mean that a relatively low

pressure is optimal, limiting engine power,

but all the fuel is burned, allowing high

efficiency.

Gas generator cycle – A small percentage

of the propellants are burnt in a preburner

to power a turbopump and then exhausted

through a separate nozzle or low down on

the main one.

Hanseo university – Air transfortation & logistics department - Aeronautical and Space Sciences

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Expander cycle – Cryogenic fuel is used to cool the walls of the combustion chamber and

nozzle.

Staged combustion cycle – A fuel or oxidizer rich mixture is burned in a turbine to power

the turbopumps and this high pressure exhaust is fed directly into the main chamber where

the remainder of the fuel or oxidizer undergoes combustion, permitting very high pressures

and efficiency.

2. Solid rocket

A solid (fuel) rocket or solid rocket is a rocket with a rocket engine that uses solid propellants.

The lower performance of solid propellants does not favor their use as primary propulsion in modern medium to large launch vehicles customarily used to orbit commercial satellites and launch major space probes.

o Solid rocket motor

A simple solid rocket motor consists of a casing, nozzle, grain and igniter. The grain behaves like a solid mass, burning in predictable fashion and producing exhaust gases.

Explain the working principle of the four-stroke reciprocating engine. (5.9)

A four-stroke engine is an internal combustion engine in which the piston completes four

separate strokes while turning a crankshaft. A stroke refers to the full travel of the piston along

the cylinder in either direction. The four separate strokes are termed:

a) Intake: This stroke of the piston begins at top dead center and ends at bottom dead

center. In this stroke the intake valve must be in the open position while the piston pulls

an air fuel mixture into the cylinder by producing vacuum pressure into the cylinder

through its downward motion.

Hanseo university – Air transfortation & logistics department - Aeronautical and Space Sciences

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b) Compression: This stroke begins at B.D.C or just at the end of the suction stroke and

ends at T.D.C. In this stroke the piston compresses the air-fuel mixture in preparation

for ignition during the power stroke.

c) Power: This is the start of the second revolution of the four stroke cycle. At this point the

crankshaft has completed a full 360 degree revolution.

d) Exhaust: During the exhaust stroke, the piston once again returns from B.D.C. to T.D.C.

while the exhaust valve is open.

o Otto cycle

Nikolaus August Otto as a young man was a traveling salesman for a grocery concern. In his

travels he encountered the internal combustion engine built in Paris by Belgian expatriate Jean

Joseph Etienne Lenoir. The 18 litre Lenoir Engine produced only 2 horsepower.

o The Intake or Admission Stroke

During the intake or admission stroke the piston moves downward as a charge of combustible

fuel and air is admitted into the cylinder through the open intake valve. At the completion of this

stroke the intake valve closes.

o The Compression Stroke

During the compression stroke the crankshaft continues to rotate, the piston is forced upward

in the cylinder and both intake and exhaust valves are closed. The movement of the piston

upward compresses the fuel air mixture

Hanseo university – Air transfortation & logistics department - Aeronautical and Space Sciences

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o Power or Expansion Stroke

As the piston approaches the top of its stroke within the cylinder, an electric spark jumps across the points of the spark plugs and ignites the compressed fuel-air mixture.

Having been ignited, the fuel-air mixture burns. It expands as it burns and drives the piston downward.

o The Exhaust or Scavenging Stroke

During the power or expansion stroke, the hot gases obtained by combustion exert

tremendous pressure on the piston to force it to move downward but near the end of the stroke

this pressure is greatly reduced because of the expansion of the gases. At this stage, the

exhaust valve opens as the crankshaft continues to revolve and the piston is again moved

upward in the cylinder by the connecting rod.

Explain the difference between the Strapdown technoligies and Platform system of

Intertial Navigation(INS) system technoligies. (6.4)

Inertial navigation is a self-contained navigation technique in which measurements provided by

accelerometers and gyroscopes are used to track the position and orientation of an object

relative to a known starting point, orientation and velocity. Inertial measurement units typically

contain three orthogonal rate gyroscopes and three orthogonal accelerometers, measuring

angular velocity and linear acceleration respectively.

o Platform and Strapdown technologies

An inertial platform, also known as a gyroscopic platform or stabilized platform, is a system

using gyroscopes to maintain a particular orientation in space despite the movement of the

vehicle they are attached to.

The original applications of INS technology used stable platform techniques. In such syste

ms, the inertial sensors are mounted on a stable platform and mechanically isolated from t

he rotational motion of the vehicle.

Modern systems have removed most of the mechanical complexity of platform systems by

having the sensors attached rigidly or “strapped down”, to the body of the host vehicle. The

potential benefits of this approach are lower cost, reduced size, and greater reliability co

mpared with equivalent platform systems.

Hanseo university – Air transfortation & logistics department - Aeronautical and Space Sciences

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o Strapdown inertial navigation concept

Accelerometers mounted directly to airframe and measure body acceleration

Horizontal accelerations computed analytically using direction cosine matrix relating body

coordinated and local level navigation coordinates

Hanseo university – Air transfortation & logistics department - Aeronautical and Space Sciences

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Explain the principles and the type of the Flight data recorder (FDR). (6.9)

Flight Data Recorder device used to record specific aircraft performance parameters. The

purpose of an FDR is to collect and record data from a variety of aircraft sensors onto a

medium designed to survive an accident.

An FDR has historically been one of two types of flight recorder carried on aircraft the other

being a cockpit voice recorder.

o Objectivec

The recorder is installed in the most crash survivable part of the aircraft, usually the tail

section. The data collected in the FDR system can help investigators determine whether an

accident was caused by pilot error, by an external event, or by an airplane system problem.

o Terminology

The term flight recorder is more precise, and the popular synonym black box is used only

informally almost never used within the flight safety industry or aviation. The recorders are not

permitted to be black in color, and must be bright orange, as they are intended to be spotted

and recovered after incidents. The term black box is a misnomer popularised by media in

general.

o Combined units

With the advent of digital recorders, the FDR and CVR can be manufactured in one fireproof,

shock proof, and waterproof container as a combined digital Cockpit Voice and Data Recorder.

Currently a CVDR is manufactured by L-3 Communications as well as other manufacturers.

o Additional equipment

Since the 1970s, most large civil jet transports have been additionally equipped with a quick

access recorder. Access to the FDR and CVR is necessarily difficult because of the

requirement that they survive an accident.

Hanseo university – Air transfortation & logistics department - Aeronautical and Space Sciences

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o ICAO Requirements

The detailed list of parameters to be recorded by FDRs is provided in section 6.3 Flight

recorders and at Attachement D to Annex 6, Vol. I. According to ICAO SARPS, combination

recorders can only be used to meet the flight recorder equipage requirements as specifically

indicated in ICAO Annex 6.

o Principles of Operation

The FDR onboard the aircraft records many different operating conditions of the flight.

Explain the principles of a Pitot static system and describe the operation of the instrument using this system. (7.4)

A pitot-static system is a system of pressure -sensitive instruments that is most often used in

aviation to determine an aircraft's airspeed, mach number, altitude, and altitude trend. A pitot-

static system generally consists of a pitot tube, a static port, and the pitot-static instruments

Hanseo university – Air transfortation & logistics department - Aeronautical and Space Sciences

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o Pitot static pressure

The pitot-static system of instruments uses the principle of air pressure gradient. It works by

measuring pressures or pressure differences and using these values to assess the speed and

altitude.

o Pitot pressure

The pitot pressure is obtained from the pitot tube. The pitot tube is most often located on the

wing or front section of an aircraft, facing forward, where its opening is exposed to the relative

wind.

o Static pressure

The static pressure is obtained through a static port. The static port is most often a flush-

mounted hole on the fuselage of an aircraft, and is located where it can access the air flow in a

relatively undisturbed area. An alternative static port may be located inside the cabin of the

aircraft as a backup for when the external static port are blocked.

o Pitot static instrument

The pitot-static system obtains pressures for interpretation by the pitot-static instruments. In

some aircraft, two ADCs receive total and static pressure from independent pitot tubes and

static ports, and the aircraft's flight data computer compares the information from both

computers and checks one againstthe other.

o Pitot-Static System and Instruments

Aircraft constantly encounter atmosphere pressure changes as they climb, descend, accelerate or decelerate. The pitot-static system - sensitive to airspeed, altitude, and rates of altitude change - provides the pressure information displayed on cabin instrumentation.

The airspeed indicator is vented to both pitot and static lines. The airspeed indicator reacts to changes between pitot air and static air. The system shown employs a heated pitot tube to prevent ice formation, a necessary feature for flight in instrument conditions.

Describe the using of a DC motor in the aircraft (7.9)

A DC motor is any of a class of electrical machines that converts direct current electrical power

into mechanical power. DC motors were the first type widely used, since they could be

powered from existing direct-current lighting power distribution systems.

Hanseo university – Air transfortation & logistics department - Aeronautical and Space Sciences

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There are two main different motor types used in model aircraft.

A brushed motor consists mainly of a cylindrical metal case containing a stator and a rotor.

The rotor is part of the motor shaft, which rotates inside the stator. The rotor has several coils

that may either have an iron core or are coreless.

The rotor coils receive electric current via a so-called commutator, which is connected to a DC

voltage through two brushes. The commutator changes the voltage polarity to the coils at a

certain instant once every turn of the motor shaft, thereby keeping the motor running.

Aircraft's flight characteristics, the combination motor/propeller, the motor's efficiency and last

but not the least, the batteries energy/weight ratio.

Jet engine

A jet engine is a machine for turning fuel into thrust. The thrust is produced by action and

reaction a piece of physics also known as Newton's third law of motion. The force of the

exhaust gases pushing backward produces an equal and opposite force called thrust that

powers the vehicle forward.

Jet engines have propelled high speed cars, particularly drag racers, with the all-time record held by a rocket car. A turbofan powered car, ThrustSSC, currently holds the land speed record.

Hanseo university – Air transfortation & logistics department - Aeronautical and Space Sciences

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Jet engines date back to the invention of the aeolipile before the first century AD. This device directed steam power through two nozzles to cause a sphere to spin rapidly on its axis.

Jet engines power aircraft, cruise missiles andunmanned aerial vehicles. In the form of rocketengines they power fireworks, model rocketry,spaceflight, and military missiles.

o Types of Jet engines

Jet engines have evolved quite a bit since Whittle's era. Now there are several distinctly

different types, each working in a slightly different way.

Turbojet engine

Whittle's original design was called a turbojet and it's still widely used in airplanes today.

Turbojets are basic, general-purpose jet engines. The engine we've explained and illustrated

up above is an example.

Hanseo university – Air transfortation & logistics department - Aeronautical and Space Sciences

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Turboprop engine

Turboprop engines have a propeller at the front and are popular in smaller, more economical

aircraft and helicopters. The propeller is driven by a jet engine mounted directly behind it.

Turbofan engine

Turbofan engines are much quieter than turbojets and are typically used in large airliners. A

turbofan engine has a large fan that sucks in air at the front. Some of the air is blown into the

compressor; the rest is blown around the outside of the combustion chamber and straight out

of the back. This bypass arrangement cools the engine and makes it much quieter. It also

produces much more thrust at both takeoff and landing.

Hanseo university – Air transfortation & logistics department - Aeronautical and Space Sciences

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Ramjet and scramjet engines

Ramjets are simple and compact jet engines little more than gas-burning pipes, typically used

to power rockets and guided missiles. Scramjets are supersonic ramjets (ones in which air

travels through the engine faster than the speed of sound).

Ramjet engine

Scramjet engine