Project-1: Powertrain for aircraft in runways

QUESTION 1

AIM : Search and list out the total weight of various types of aircrafts.

• If we are find the weight of the aircrafts consider different specifications are different weights of the aircraft like maximum landing weight,maximum takeoff,operating empty weight.
• to estimate the weight of the aircraft below words are consider

MAXIMUM LANDING WEIGHT(MLW) :

• It is the amount of maximum weight at which the aircraft is permitted to land the below figure shows the takeoff weight components.
• The operation landing weight may be limited to a weight lower than the maximum landing weight by the most restrictive of the following requirements:
• Aircraft performance requirements for a given altitude and temperature:

1. landing field length requirements,
2. approach and landing climb requirements.

• Noise requirements

MAXIMUM TAKE OOF WEIGHT( MTOW) :

• It is defined as the the maximum amount of weight at which the pilot of the aircraft is allowed to attempt to take off is know as the maximum take off weight
• Maximum permissible takeoff weight or regulated takeoff weight, varies according to flap setting, altitude, air temperature, length of runway and other factors. It is different from one takeoff to the next, but can never be higher than the MTOW.

OPERATING EMPTY WEIGHT :

• It is mainly equivalent to the basic empty weight on the light aircraft and aslo basic weight of an aircraft including the crew i.e all the fluids required for the operation they are engine oil engine coolant water etc,the un usable fuel and all the operated items and the equpiment used for flight,but excluding the usable fuel and payload
• The weight added to the aircraft above its OEW for a given flight is variable and includes fuel for the flight and the cargo. Cargo depends upon the type of aircraft; i.e., passengers plus baggage for a transport or commuter airplane, materiel for a cargo airplane, stores for fighters/bombers and service loads such as meals and beverages. Fuel and cargo weights may alter the centre of gravity and flight performance, and require careful calculation before each flight.

ZERO FUEL WEIGHT :

• This is the total weight of the airplane and all its contents (including unusable fuel), but excluding the total weight of the usable fuel on board.
• As a flight progresses and fuel is consumed, the total weight of the airplane reduces, but the ZFW remains constant.
• Maximum zero fuel weight (MZFW) is the maximum weight allowed before usable fuel and other specified usable agents (engine injection fluid, and other consumable propulsion agents) are loaded.

PAYLOAD :

• Payload is the object or the entity which is being carried by an aircraft or launch vehicle. Sometimes payload also refers to the carrying capacity of an aircraft or launch vehicle, usually measured in terms of weight.
• Depending on the nature of the flight or mission, the payload of a vehicle may include cargo , passengers, flight crew, munitions scientific instruments or experiments, or other equipment.
• Extra fuel, when optionally carried, is also considered part of the payload.

REGULATED TAKEOF WEIGHT(RTOW) :

• It mainly depends on the different factors i.e flap seetings , air temperature,length of the runway and also alititude the RTOW or the maximu permissible takeoff weight changes for each takeoff .it should not be higher than the MTOW.

MAXIMUM RAMP WEIGHT(MRW) :

• It is aslo called as the maximum taxi weight (MTW) it is the maximum amount of the weight used for measuring an aircraft on the ground.

AIRCRAFT GROSS WEIGHT :

• It is the total weight of an aircraft at any moment during when the aircraft or ground operation this also decreases during flight due to fuel and oil useage.

MANUFACTURE EMPTY WEIGHT :

• It is aslo called as the licensed empty weight,in this weight of the aircraft is built and includes the weight of the structure power plant systems and other equipment that are to be considered as an integral part of the aircraft this inculdes any baggage or passengers, are fuel

TYPES OF AIRCRAFTS AND THEIR WEIGHTS:

Mc DONNELL DOUGLAS MD-11:

• It is an american trijet wide body airliner manufactured by the american Mcdonnell douglas and then by boeing it was first launched on the Dec 30, 1986 and its certfication is achieved on Nov 8 its first delivery was to finnair on dec 7,1990

MTOW(KG): 273,300 MLW[Tonnes] : 185

LOCKHEAD C-5 :

• It is the larger military transport aircraft designed and built by the lockhead and now it is mainted by the lockheed martin it used in the united state air force (USAF) with a heavy range capability it has many similarities with the boeing c-17 aircraft.

MTOW(KG): 381,000 MLW[Tonnes] : 288.147

BOEING 747-8:

• The boeing 747-8 is first devleoped by the boeing commercial airplanes and it is the largest variant of the 747.

MTOW(KG):443,613 MLW[Tonnes] : 306.175

ANTONOV AN-225 MRIYA:

• It was a strategic airlift cargo aircraft designed in the 1980s by the Antonov design bureau in the soviet union,after the succesfully fullfilling the military missions the aircrafts was not used for eight years

MTOW(KG): 640,000 MLW[Tonnes] : 591.7

Airbus A380 :

• It is the larger wide body airliner that was first developed by the airbus it is the worlds largest passenger airliner,it was first started in 1988 and luanched in the year 1990 as competet to boeing747 in the market
• In the full lenth double deck air craft it has 525 seating capacity and the maximum certified capacity for 853 passengers

MTOW(KG): 575,000 MLW[Tonnes] : 394

ATR 42:

• It is regional airline produced by the franco-italian manufacturer ATR with finsl assembly in toulouse,france it was lainched on 4 nov 1981 with ATR it was certification was permitted on september 1985.

MTOW(KG): 18,600 MLW[Tonnes] : 18.3

EMBRAER EMB-505:

• It is a single pilot certified light bussiness jet developed by the brazilian aerospace manufacturer embraer it can carry up to 11 passengers.

MTOW(KG): 8,150 MLW[Tonnes] : 7.65

SAAB 340:

• It is the swedish twin engine aircraft designed produced by the saab AB and fairchild aircraft it is designed upto the seating 30-36 passengers as of july 2018 there were 240 operational aircraft used by 34 different operators.

MTOW(KG): 13,150 MLW[Tonnes] : 12.930

EMBRAER EMB 120 BRASILIA:

• It was a twin turboprop commuter airliner produced by the embraer of brazil The Brasilia attracted immediate interest from many regional airlines, particularly in the US. The size, speed and ceiling allowed faster and more direct services around the US and Europe, compared to similar aircraft

MTOW(KG): 11,500 MLW[Tonnes] : 11.25

PILATUS PC-24:

• It is the light bussiness jet produced by the pilatus aircraft of switzerland it mainly works on the twin engine jet began it was first introduce on 21 may,2013 and used on 1 aug,201 with maiden flight on 11may,2015

MTOW(KG): 8,300 MLW[Tonnes] : 7.665

QUESTION 2

AIM : To find is there any difference between ground speed and air speed?

There is a difference between ground speed and air speed to understand this we should take in to account wind speed too.

GROUND SPEED :

• 
• It is defined as the speed of an airplane with the relation to the ground compare to the airspeed.Example: for suppose when at critical altitude the aeroplanes may have a ground speed anywhere between the 300-600 m/hr when passenger jets usually critical at the same airspeed then the wind can make a big difference to that of speed at which the aircraft passes over the ground.

AIR SPEED :

• 
• This is the difference in vector between the ground speed and the windspeed ,and airspeed=groundspeed-windspeed,still the day the airspeed is equal to the ground speed but in some cases the wind is blowing in the same direction which the aircraft is moving then the airspeed will be less than the groundspeed.
• Airspeed is the vector difference between the ground speed and the wind speed.
• Airspeed = Ground Speed - Wind Speed

DIFFERANCE BETWEEN GROUND SPEEDS&AIR SPEEDS:

1. In ground speed the airplanes speed is relative to the surfacr of the earth but in the air speed it is the speed relative to the air it is flying in.
2. As we discussed above the true airspeed is simply the speed at which an aircraft is moving relative to the air it is flying and aslo the speed at which the air is flowing around the aircrafts wings
3. On the other hand the ground speed is the aircrafts speed relative to the ground here we should know one thing that is its horizontal ratern than vertical speed of an aircraft climbing vertically would have a zero ground speed
4. In the other words were airspeed is what it determines whether there is enough airflow around an aircraft to make a fly ,but the ground speed is what it determines how fast an aircraft will get to its final destination.

EFFECT OF WIND ON GROUND SPEED:

• Here the relationship between the airspeed and ground speed is simple i.e ground speed is the sum of air speed and windspeed.
• 1st example taking wind speed as 20 km/hr and runway is east-west runway the wind blowing towards west and the flight runs at 80 km/hr the wind speed acting in the west and the flight takes off east then the

Airspeed=Groundspeed(80)- Wind Speed(-20) =100 km/hr

If the planes runs towards west along the wind blowing direction then

the Airspeed=Groundspeed(80) - Wind Speed(20)=60km/hr

Hence there is a difference between ground speed and air speed.

• 2nd example if the aircraft is flying in tha same direction of that of wind is blowing then the aircraft experiences a tailwind and its ground speed is higher then that of its airspeed ,in similar case if the wind is blowing against the direction of the aircraft is travelling the aircraft experiences a head wind and its ground speed is lower then that of the airspeed.
• 
• For observing the above figure consider as example image that the aircraft that cruises at an airspeed of 500m/hr that should has to be cover a ground distance of 2000miles. Soif there is no wind at all then the both aircrafts airspeed and ground speed would be the same 500miles/hr and the aircraft would reach its final destination in 4hours;
• for suppose if there is 100m/hr headwind wind blowing against the aircraft direction of travel the aircraft would still be travelling at an airspeed of 500 m/hr however its ground speed would be the just 400m/hr
• 100 miles slower than that of its airspeed and it would take the aircraft 5hrs to reach its final destination.
• so in conclusion if there is a 100 m/hr tailwind blowing in the same direction as the aircraft travel then the aircraft would still be travelling at an airspeed of 500 m/hr but the ground spedd would be 100m/hr faster and 600m/hr the aircraft would reach its destination in just 3hrs and 20min.
• So for the pilots both the airspeed and ground speed are important which the first of those helps in them to make sure that they are flying fast enough to take off and so on,on the other hand it helps them to know how long it will take them to get from one place to another
• similarily when the passenger you should only need to be concerned about the ground speed as that will tell you how fast are you flying from the intiall state to final destination how fast you will be able to get to the AIM.

QUESTION 3

AIM : Why is it not recommended to use aircraft engine power to move it on the ground at Airport

• We are assuming passenger commuter aircraft and large airliners. Aircraft move using their own engine power all the time on the airport apron and taxiways under their own power to go towards runways and after landing taxi to their assigned gate.
• The only time they use external assistance is to pushback from the gate. Large turbofan aircraft need help to reverse via a pushback tractor. The engines are turned on after the pushback is complete and the aircraft can move forward under It’s own power.
• To be accurate, some aircraft can reverse using a variable pitch prop or thrust reversing on turbofans but generally reversing is done via pushback tractors.
• Blasting jet reversers blows debris In the crowded gate area creating foreign object damage hazard for adjacent aircraft, gate equipment or terminal waiting area glass windows.Here for the movement of the aircraft in ground stage it uses its own engine power which is called as the taxing.

Why The Aircraft not run on the ground?

• Mainly the mechanical failures or engine failures may occur from leaks in turbine parts leaks in oil pump problems and either outside or inside the engine.
• Loss of control can be happen during the high power engine running it results in damgaging the aircrafts its self
• plane engine produces more unwanted sounds when more than one plane will move this will effect the passeangers .
• There may aslo risk to the ground support staff which effect the aircafts very closely
• If the ground stage engine power taxing is push back truck the aircraft will way to runway to save the fuel and reduces impact on the engine airccraft.
• The risks which may arise from engine ground running relate to the potential for loss of control of the aircraft by those persons occupying the pilot seats in the flight deck. Unwanted consequences from such static running are mainly related to those arising from the unintended movement of the aircraft during engine running - effectively a loss of control - especially during high power engine running. Damage can occur to the aircraft itself, other aircraft nearby or to airside structures. In addition, there is a risk of injury to ground support personnel who may be in relatively close proximity to the aircraft.
• When modern jet engines are operated at rated thrust levels, the exhaust wake can exceed 375 mi/h (325 kn or 603 km/h) immediately aft of the engine exhaust nozzle. This exhaust flow field extends aft in a rapidly expanding cone, with portions of the flow field contacting and extending aft along the pavement surface (fig. 1). Exhaust velocity components are attenuated with increasing distance from the engine exhaust nozzle. However, an airflow of 300 mi/h (260 kn or 483 km/h) can still be present at the empennage, and significant people and equipment hazards will persist hundreds of feet beyond this area. At full power, the exhaust wake speed can typically be 150 mi/h (130 kn or 240 km/h) at 200 ft (61 m) beyond the airplane and 50 to 100 mi/h (43 to 88 kn or 80 to 161 km/h) well beyond this point.
• 
• The extensive noise arises from the engine power also dangerous for humans and other living things around the vicinity.Hence for the above reasons it is not recommended to use engine power to move on the ground

QUESTION 4

AIM : To know how an aircraft is pushed to runway when its ready to take off

• taxiing refers to the movement of an aircraft on the ground, under its own power. The aircraft moves on wheels. An airplane uses taxiways to taxi from one place on an airport to another; for example, when moving from a terminal to the runway. push back truck reverse the aircraft into the taxing position pushing it with the towbar which is attached to the nose wheel strut now in most modern systems by the actuall lifiting the wheel .that the speeds up coupling and decoupling hence the aircraft taxis to the runway which is ready to depart at the prefered time.

TWO STEPS INVOLVED IN TAKEOF:

1)Towing

2)Taxing

1)TOWING:

• When the aircraft is to be towed before is just moved a well known person should be in the flight to operate or control the plane if the tow bars becomes unhoked then the aircraft be stopped and its stops the damgage.
• Here the aircraft is mainly moved by the tow tractor it is aslo called as tag ,in similar case when the aircraft is small in size the moved by the hand pushing the aircrafte.
• By this towing there is aslo a dangerous problems arised which cause the damge to the aircraft and injury to staff there is procedure for towing the aircraft but the manufactures already made a detailed insturctions how to operate .

• the above picture is a towbar most of the towbars consist of the small wheels which are used in towing the smaller aircrafts this towing is attched to the front part of the aircraft Here the towbars play key role in carrying the aircraft they are als avaliable for general use for many towing operations this bars are madeup of the high tensile strength which helps to pull the heavy aircrafts

2)TAXING:

• Can you observe the below figure the man giving the instruction to the pilot for taxing

• Mainly the air crafts uses the taxiways to move from one place to another place for example if we are moving from the station to runway the taxing is not used for accelrating for long run or the decelerating run instantly that taakeoff takes place after landing.This can be desceribed by the movement of an aircraft on the ground which uses its own power in contrast to pushback while the aircraft is moved by the tug,as we all know most of the aircrafts moves on wheels but here it also includes floats mainly used to travel in the water based conditions

QUESTION 5:

AIM: Learn about take off power, tyre design, rolling resistance, tyre pressure, brake forces when landing.

• TAKE OOF POWER :

For light aircraft, usually full power is used during takeoff. Large transport category (airliner) aircraft may use a reduced power for takeoff, where less than full power is applied in order to prolong engine life, reduce maintenance costs and reduce noise emissions. In some emergency cases, the power used can then be increased to increase the aircraft's performance. Before takeoff, the engines, particularly piston engines, are routinely run up at high power to check for engine-related problems. The aircraft is permitted to accelerate to rotation speed (often referred to as V_r). The term rotation is used because the aircraft pivots around the axis of its main landing gear while still on the ground, usually because of gentle manipulation of the flight controls to make or facilitate this change in aircraft attitude (once proper air displacement occurs under / over the wings, an aircraft will lift off on its own; controls are to ease that in).

The nose is raised to a nominal 5°–15° nose up pitch attitude to increase lift from the wings and effect liftoff. For most aircraft, attempting a takeoff without a pitch-up would require cruise speeds while still on the runway.

• Tyre Design:

Based on the type of plies used the tyres can be:

1] Radial ply tires - these tyres feature a flexible casing which is constructed of rubber-coated ply cords which extend around the beads and are substantially at 90° to the centerline of the tread. The casing is stabilized by an essentially inextensible circumferential belt.

2] Bias ply tires - these tyres feature a casing which is constructed of alternate layers of rubber-coated ply cords which extend around the beads and are at alternate angles substantially less than 90° to the center line of the tread.

Based on the method for containing the inflation gas the tyres can be:

Tube-type tyres - these require tubes for inflation retention.

Tubeless tyres - these do not require tubes. They are constructed with an innerliner (integral rubber lining that is engineered to prevent the diffusion of the inflation gas into the casing.).

• Rolling Resistance:

The resistance offered by the tyres against motion of vehicle/aircraft is called as rolling resistance, the rolling resistance is produced during take off/landing in the runway.

• Tyre Pressure:

Aircraft tires are usually inflated with nitrogen to minimize expansion and contraction from extreme changes in ambient temperature and pressure experienced during flight. Dry nitrogen expands at the same rate as other dry atmospheric gases (normal air is about 80% nitrogen), but common compressed air sources may contain moisture, which increases the expansion rate with temperature.

Tests of airliner aircraft tires have shown that they are able to sustain pressures of maximum 800 psi (55 bar; 5,500 kPa) before bursting. During the tests the tires have to be filled with water, to prevent the test room being blown apart by the energy that would be released by a gas when the tire bursts.

The main landing gear on the Concorde was typically inflated to 232 psi (16.0 bar), whilst its tail bumper gear tires were as high as 294 psi (20.3 bar). The high pressure and weight load on the Concorde tyres were a significant factor in the loss of Air France flight 4590

• Brakes Forces When Landing:

In general, when the wheels touch the ground, a set of spoilers raise up quickly, which kills the lift provided by the wings. (There are two sets seen in the image below: ground spoilers that only deploy on landing, and spoilers that are used in flight as speed brakes as well as on landing.) While the spoilers provide some drag, their primary purpose is to stop the plane from actually flying, putting all of the weight on the landing gear and in turn making the brakes that much more effective.

Aircraft have highly-engineered, multi-disc brakes made of a carbon-steel material. Manufacturers include Honeywell and Goodrich, part of Collins Aerospace. In general, the brakes are composed of discs that rotate with the wheel and separate discs that are fixed. When pressure is applied—and below you see pressure applied from the right fixed disc on all of the discs—the entire assembly compresses to create the braking action. Carbon brakes are standard today; they cool faster than steel brakes (their predecessor) and can weigh up to 700 pounds less. That represents a significant weight saving for airlines.

Auto Brakes:

Wheel brakes are usually selected to engage automatically after landing. These are called “autobrakes”.that all airliners have several levels of autobrake “severity”. The crew will decide which is the most appropriate to use for every landing depending upon factors like the length of runway, if it is wet or dry, or if the pilots want to exit the runway at a particular point. “For a short wet runway you might select autobrake 3, or MED on the Airbus. For a long dry runway you might select autobrake 1 or LOW on the Airbus".

QUESTION 6(A)

AIM : To calculate the force and power required to push / pull an aircraft by a towing vehicle With necessary assumptions.

SOLUTION :

forces required to push or pull the aircraft are

1) rolling resistance force

2) aerodynamic force

using rolling resistance we get,

F=cn,

F= c*m*g ( n = m*g)

using aero dynamic force we get,

Fd=1/2pv^2CdA

where ,

Fd=drag force

rho=density

Cd=is thr drag coefficient

A=area taken as reference

assume that ,

mass of towing vehicle = 30,000 kg

mass of aircraft = 135,000 kg

So here,the total mass(m)= 30000+135,000=165,000 kg

Area=15m^2

Speed of the vehicle = 20kmph

here we need to convert the 20kmph into m/sec

we get, 20*(1000/3600)=5.5m/sec

Drag coefficient cd = 0.55

Air denisty (p) = 1.155kg/m^3

By calculating the rolling resistance force Frr we get=Crr*m*g

0.01*165000*9.8 = 16.170N

Now calculating aerodynamic drag force

Fd = 0.5*p Cd*A*v^2

=0.5*1.155*15*0.55*(5.55)2

=146.754N

Now the total force required to push/pull the air craft by the towing vehicle is Frr+Fd

16.170+146.754

= 16316.75

now the power = force*velocity

16316.75*5.55

Total power=90.557kw

QUESTION 6(B):

AIM: To Develop the model for the calculated force and power using Simulink.

SIMULINK MODEL :

Blocks used for simulation

• constant
• product
• sum
• display
• square

observing above model consider below points

• We need to multiply both the force and velocity for calculating the power this can be done by using the product block
• Next we need to add the both the Frr and Fd by using the sum block for calculating the total force which is shown in above figure
• For finding the rolling resistance we used the product to multiply the values total mass and gravity which we have to give in constant block
• Now in same way for calculating the drag force we have to multiply the velocity drag coefficient and area and constant value is 0.5 which we have to entire in the block
• Here for converting the velocity from kmph to m/sec we have multiplied it with 5/18 should be given in the constant block

RESULTS :

we can observe the rolling resistance force is 16170

total force is 16317.0486111

power is 90650.270061728

drag force of aircraft is 147.0486111

QUESTION 7(A):

AIM: To Design an electric powertrain with type of motor, it’s power rating, and energy requirement to fulfill aircraft towing application in Simulink. Estimate the duty cycle range to control the aircraft speed from zero to highest. Make all required assumptions. Prepare a table of assumed parameters. Draw a block diagram of powertrain.

(Hint :DC7 Block)

BLOCK DIAGRAM OF POWERTRAIN:

he force required to push or pull the aircraft =16.316 KN

power required = 90.557kw

Now let us assume that the radius of the tyre of the tug is 25 inches=0.635

gear ratio = 10

efficency (nt)=90%

Motor efficiency =97%

Torque required for the wheels (Tw)= total force*radius

16.316*0.635

=10.360 knM

Motor torque wheel torque/ (gear ratio nt)

10.360/(10* 0.90)

=1.1511 Knm

Now for nm= 97% then the required motor torque(Tm)=1.1511/0.97=1.186knm

Same the total power required by the motor consedring all the efficiences (pt) = 90.557/(0.90*0.97) = 103.73kw

Let assume the towing operations was done for 20 min (0.33hrs) duration

then the total energy consumed = 103.73*0.33 = 34.23kwh

now if consider the batter capacity =240 kw is used by the towing vehicle then the duty cycle range to control the speed from 0 to max speed 3m/s is

duty cycle = 103.73/240 = 0.43

Therefore controller will provide a duty cycle ranging from 0 to 43% which is control the towing speed

SIMULINK MODEL FOR POWERTRAIN:

OUTPUT RESULTS :

we can see the output wave form s of duty cycles, armature voltage, armature current and motor speed

IGBT 1 AND 4 is 0.7

IGBT 2 AND 3 IS 0.4

ARMATURE VOLTAGE IS 400

ARMATURE CURRENT IS 220

MOTOR SPEED 500

QUESTION 7(B):

AIM: To Design the parameter in exceel sheet

CONCLUSION :

We have succesfully completed the given tasks

Case-1:we have list out the total weight of the various types of aircrafts

Case-2:we have studied and understood differance between ground speeed&air speed

Case-3:we have understood that aircraft engine power is not recommended to move it on the ground at airport

Case-4:we are find how an aircraft is pushed to runway when its ready to take off

Case-5: we have Learn about take off power, tyre design, rolling resistance, tyre pressure, brake forces when landing

Case-6(A):we have find the necessary assumptions, calculate the force and power required to push / pull an aircraft by a towing vehicle

Case-6(B):Develop the model for the calculated force and power using Simulink

Case-7(A):we have Design an electric powertrain with type of motor, it’s power rating, and energy requirement to fulfill aircraft towing application in Simulink. Estimate the duty cycle range to control the aircraft speed from zero to highest. and done to Make all required assumptions. and Preparing a table of assumed parameters. succesfully Draw the block diagram of powertrain

Case-7(B):we done to design the parameters in excel sheet