Project-1: Powertrain for aircraft in runways

Powertrain for aircraft in runways

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

Solution:

MTOW = Maximum take-off weight, MLW = Maximum landing weight, TOR = Take-off run , LR = Landing run

AIRPLANES:

Type	MTOW [kg]	MLW [tonnes]	TOR [m]	LR [m]	ICAO category	FAA category
Antonov An-225	640,000	591.7	3500		Heavy	Super
Scaled Composites Model 351 Stratolaunch	589,670		3660		Heavy	Super
Airbus A380-800[1][2][3]	575,000	394	3100	1930	Super	Super
Boeing 747-8F	447,700	346.091	3100	1800	Heavy	Heavy
Boeing 747-8	443,613	306.175	3100		Heavy	Heavy
Boeing 747-400ER	412,770	295.742	3090		Heavy	Heavy
Antonov An-124-100M	405,060	330	2520	900	Heavy	Heavy
Boeing 747-400	396,900	295.742	3018	2179	Heavy	Heavy
Lockheed C-5 Galaxy[4][5][6]	381,000	288.417	2530	1494	Heavy	Heavy
Boeing 747-200[7]	377,840	285.700	3338	2109	Heavy	Heavy
Boeing 747-300[7]	377,840	260.320	3222	1905	Heavy	Heavy
Airbus A340-500[8]	371,950	240	3050	2010	Heavy	Heavy
Airbus A340-600[8]	367,400	256	3100	2100	Heavy	Heavy
Boeing 777F	347,800	260.816	2830		Heavy	Heavy
Boeing 777-300ER	351,800	251.29	3100		Heavy	Heavy
Boeing 777-200LR	347,450	223.168	3000		Heavy	Heavy
Boeing 747-100[7]	340,200	265.300			Heavy	Heavy
Airbus A350-1000	308,000	233.5			Heavy	Heavy
Boeing 777-300	299,370	237.683	3380		Heavy	Heavy
Boeing 777-200ER	297,550	213.00	3380	1550	Heavy	Heavy
Airbus A340-300[8][9]	276,700	190	3000	1926	Heavy	Heavy
McDonnell Douglas MD-11	273,300	185	2990	1890	Heavy	Heavy
Airbus A350-900	270,000	175	2670	1860	Heavy	Heavy
Ilyushin Il-96M	270,000	195.04	3115	2118	Heavy	Heavy
McDonnell Douglas DC-10	256,280	183	2990	1890	Heavy	Heavy
Boeing 787-9[10]	254,000	192.777	2900		Heavy	Heavy
Boeing 787-10[10]	254,000	201.849			Heavy	Heavy
Airbus A340-200[8][11]	253,500	181	2990		Heavy	Heavy
Airbus A330-900	251,000	191,000	3100		Heavy	Heavy
Ilyushin IL-96-300	250,000	175	2600	1980	Heavy	Heavy
Airbus A330-300[12][13]	242,000	185	2500	1750	Heavy	Heavy
Airbus A330-200[12][13]	242,000	180	2220	1750	Heavy	Heavy
Lockheed L-1011-500	231,300	166.92	2636		Heavy	Heavy
Boeing 787-8[10]	228,000	172.365	3300	1695	Heavy	Heavy
Lockheed L-1011-200	211,400				Heavy	Heavy
Ilyushin IL-86	208,000	175			Heavy	Heavy
Boeing 767-400ER	204,000	158.758	3414		Heavy	Heavy
Airbus A300-600R[14]	192,000	140	2385	1555	Heavy	Heavy
Boeing 767-300ER	187,000	136.08	2713	1676	Heavy	Heavy
Concorde	185,000	111.1	3440	2220	Heavy	Heavy
Airbus A300-600[14]	163,000	138	2324	1536	Heavy	Heavy
Boeing 767-300	159,000	136.078	2713	1676	Heavy	Heavy
Airbus A310-300[14]	157,000	124	2290	1490	Heavy	Heavy
Vickers VC10	152,000	151.9			Heavy	Heavy
Boeing 707-320B[15]	151,000	97.5			Heavy	Heavy
Boeing 707-320C[15]	151,000	112.1			Heavy	Heavy
Douglas DC-8-61	147,000				Heavy	Heavy
Airbus A310-200[14]	142,000	123	1860	1480	Heavy	Heavy
Airbus A400M	141,000	122	980	770	Heavy	Heavy
Douglas DC-8-32	140,000				Heavy	Heavy
Douglas DC-8-51	125,000				Medium	Large
Boeing 757-300	124,000	101.6	2550	1750	Medium	Large
Boeing 707-120B[15]	117,000	86.3			Medium	Large
Boeing 757-200	116,000	89.9	2347	1555	Medium	Large
Boeing 720B[16]	106,000	79.5			Medium	Large
Boeing 720[16]	104,000	79.5			Medium	Large
Tupolev Tu-154M	104,000	80			Medium	Large
Tupolev Tu-204SM	104,000	87.5	2250		Medium	Large
Convair 880	87,500				Medium	Large
Boeing 737-900	85,000	66.36	2500	1704	Medium	Large
Boeing 737-900ER	85,000	71.35	2804	1829	Medium	Large
Boeing 727-200 Advanced[17]	84,000	70.1			Medium	Large
Airbus A321-100[18]	83,000	77.8	2200	1540	Medium	Large
Boeing 737-800	79,000	65.32	2308	1634	Medium	Large
Boeing 727-200[17]	78,000	68.1			Medium	Large
McDonnell-Douglas MD-83	73,000	63.28			Medium	Large
Boeing 727-100[17]	72,500	62.4			Medium	Large
Boeing 727-100C[17]	72,500	62.4			Medium	Large
McDonnell-Douglas MD-90-30	71,000	64.41	2165	1520	Medium	Large
de Havilland Comet 4	70,700				Medium	Large
Boeing 737-700	70,000	58.06	1921	1415	Medium	Large
Airbus A320-100[18]	68,000	66	1955	1490	Medium	Large
Boeing 737-400	68,000	54.9	2540	1540	Medium	Large
de Havilland Comet 3	68,000				Medium	Large
Boeing 377	67,000				Medium	Large
Boeing 737-600	66,000	54.66	1796	1340	Medium	Large
Airbus A220-300	65,000	57.61	1890	1494	Medium	Large
Hawker Siddeley Trident 2E	65,000				Medium	Large
Airbus A319[18]	64,000	62.5	1850	1470	Medium	Large
Boeing 737-300	63,000	51.7	1939	1396	Medium	Large
Boeing 737-500	60,000	49.9	1832	1360	Medium	Large
Airbus A220-100	59,000	50.80	1463	1356	Medium	Large
Airbus A318[18]	59,000	57.5	1375	1340	Medium	Large
Boeing 717-200HGW	55,000	47.174	1950		Medium	Large
Douglas DC-7	55,000				Medium	Large
de Havilland Comet 2	54,000				Medium	Large
Boeing 717-200BGW	50,000	46.265	1950		Medium	Large
de Havilland Comet 1	50,000				Medium	Large
Douglas DC-6A	48,600				Medium	Large
Douglas DC-6B	48,500				Medium	Large
Embraer 190[19]	48,000	43	2056	1323	Medium	Large
Caravelle III	46,000				Medium	Large
Fokker 100	46,000	39.95	1621	1350	Medium	Large
Douglas DC-6	44,000				Medium	Large
Avro RJ-85	42,000	36.74			Medium	Large
Handley Page Hermes	39,000				Medium	Large
Embraer 175[20]	37,500	32.8	2244	1304	Medium	Large
Bombardier CRJ900[21]	36,500	33.345	1778	1596	Medium	Large
Embraer 170[22]	36,000	32.8	1644	1274	Medium	Large
Bombardier CRJ700	33,000	30.39	1564	1478	Medium	Large
Douglas DC-4	33,000				Medium	Large
Vickers Viscount 800	30,400				Medium	Large
Bombardier Q400	28,000	28.01	1219	1295	Medium	Large
Bombardier CRJ200	23,000	21.319	1918	1479	Medium	Large
ATR 72-600	22,800	22.35	1333	914	Medium	Large
Saab 2000	22,800	21.5	1300		Medium	Large
Embraer ERJ 145	22,000	19.3	2270	1380	Medium	Large
ATR 42-500	18,600	18.3	1165	1126	Medium	Small
Saab 340	13,150	12.930	1300	1030	Medium	Small
Embraer 120 Brasilia	11,500	11.25	1560	1380	Medium	Small
BAe Jetstream 41	10,890	10.570	1493	826	Medium	Small
Learjet 75[23]	9,752	8.709	1353	811	Medium	Small
Pilatus PC-24[24]	8,300	7.665	893	724	Medium	Small
Embraer Phenom 300[25]	8,150	7.65	956	677	Medium	Small
Beechcraft 1900D	7,765	7.605	1036	853	Medium	Small
Cessna Citation CJ4[26]	7,761	7.103	1039	896	Medium	Small
de Havilland Hercules	7,000				Medium	Small
Embraer Phenom 100	4,800	4.43	975	741	Light	Small

HELICOPTER:

Type	MTOW [pounds]	MTOW [kg]	Power output [kW]	Power to weight [W/kg]	Rotor diameter [m]
Mil Mi-12[27]	231485	105000	19200	182	2 x 35
Mil Mi-26[28]	123459	56000	17000	343	1 x 32
Sikorsky CH-53E[29]	73500	33300	9810	294	1 x 24
Boeing CH-47D/F Chinook[30]	50000	22680	7058	311	2 x 18.3
AgustaWestland AW101[31]	34,392	14600	4698	321	1 x 18.59
Sikorsky S-92[32]	26500	12020	3758	312	1 x 17.17
Eurocopter EC225 Super Puma	24692	11200	3552	317	1 x 16.2
Boeing Vertol CH-46 Sea Knight[33]	24300	11000	2800	254	2 x 15.24
NHIndustries NH90	23370	10600	3324	314	1 x 16.3
Eurocopter AS532 Cougar	19840	9000	2370	263	1 x 15.6
Bell 412EP	11900	5397	1864	345	1 x 14.0
Eurocopter EC145 C-2	7903	3585	1100	307	1 x 11.0
Eurocopter EC135 P2+/T2+	6415	2910	944	325	1 x 10.2
Eurocopter EC635 P2	6393	2900	1218	420	1 x 10.2
AeroVelo Atlas (human powered)	282	128	1.1	8.5	4 x 20.2

COVERTIPLANES:

Type	MTOW [kg]	Power output [kW]	Power to weight [W/kg]	Rotor diameter [m]
Bell Boeing V-22 Osprey	27445	6150	224	2 x 11.58
Bell-Agusta BA609	7600	1447	190	2 x 7.92
Bell XV-15	6009	1156	192	2 x 7.62

2. Difference between ground speed and air speed:

SOLUTION:

GROUND SPEED:

A reference point picked on the ground, the aircraft moves relative to the reference point at the ground at its speed is called ground speed.

AIR SPEED:

Air speed is the difference between ground speed and wind speed. Wind speed is nothing but speed of the wind which will be headwind (opposite to which the airplane strikes) or tailwind ( the wind flows parallel along airplane).

Air speed = Ground speed - Wind speed.

3. Why is it not recommended to use aircraft engine power to move it on the ground at Airport?

SOLUTION:

High engine thrust during maintenance activity can cause considerable damage to airplanes and other elements in the airport environment by throwing debris or weak asphalt road which turn into minor fragments. This is because airflow from the propellors would be around 170km/hr to 400km/hr. Also when taxiing it is very important to look after the precautions so that the high engine thrust activity could not damage any of the nearby planes, elevators, maintenance workers.

Foreign object damage (FOD) caused by high engine thrust can affect airport operations as it relates to

• Airplane structure.
• Flight controls.
• Equipment and personnel.

4. How an aircraft is pushed to runway when its ready to take off?

SOLUTION:

The forward movement of an aircraft, usually with engines off, using the power of a specialised ground vehicle attached to or supporting the nose landing gear. It may occur for the movement of both in service and out of service aircraft. Once the person in charge on the flight deck of the aircraft has given their confirmation of ‘brakes released’ to the person in charge of the ground crew vehicle who are to carry out the tow, the ground crew become responsible for the safe manoeuvring of the aircraft. The ‘traditional’ method of allowing the ground vehicle to move an aircraft is to attach it to the aircraft nose landing gear by means of a towbar. An alternative method which is becoming more common for towing is the use of a specialised vehicle called a ‘towbarless tug’. This positions two low level ‘arms’ either side of the aircraft nose landing gear and these are used to engage with the aircraft gear leg and raise it slightly off the ground.

TAXIING VS TOWING:

It’s important to note that taxiing isn’t the same as towing. When many people hear the word “taxiing,” they envision a ground vehicle physically moving an airplane on the runway. Taxiing, though, specifically involves the use of an airplane’s own propulsion system to move while on the runway. Towing, on the other hand, refers to the use of a ground vehicle. Known as a tug, these ground vehicles connect to airplanes so that they can move and turn airplanes.

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

SOLUTION:

TAKE OFF POWER:

When airplanes are lined up on the runway and cleared for take-off, the pilot will start to advance the thrust levers. On aircraft that are powered by fan engines – especially aeroplanes like the AIRBUS FAMILY where the engines are relatively large – inertia in the big fans at the front may mean that both or all engines do not always ‘spool up’ at the same rate. Until this has happened, the pilot should not advance the throttles any further as to do so could set up an asymmetry that he/she might find difficult to control through nose-wheel steering alone. Once the engines have all ‘spooled up’ it is safe to advance the thrust levers together to the position that will enable the engines to deliver the amount of thrust required for take-off. It is for ‘spool up’ reasons that tower controllers may sometimes observe a hesitation – typically 6 to 10 seconds - after the aeroplane begins to roll forward before its acceleration along the runway appears ‘normal’, and why pilots may not always seem to respond quickly to requests to ‘expedite departure’. The required thrust should be attained before the aeroplane’s indicated air speed passes 80kts. In order to reduce the likelihood of a rejected take-off resulting in an over-run or other undesirable outcome, it is often stated in the SOPs that once above a specified speed during the take-off roll the take-off should only be rejected for specified occurrences. The specified speed is typically 80 knots. Below this speed the take-off may be rejected for any reason. Above the specified speed it is typical for the SOPs to state that the take-off should only be rejected for an engine failure, any type of fire or an unsafe condition that would render the aircraft unable to fly. The call at 80 knots is also used to check that the pilots have not become incapacitated during the take-off roll. If the PM does not make the call, or if the PF does not respond, it could be due to incapacitation and the take-off should be aborted.

TYRE DESIGN:

An aircraft tyre is constructed for the purpose it serves.

1. They support the weight of an aircraft while it is on the ground.
2. It also provides the necessary traction for braking and stopping of an aeroplane.
3. Tyre also helps to absorb the shock of landing and provide cushioning the roughness of takeoff, roll-out, and taxi operations.

Unlike an automobile or truck tyre, it does not have to carry a load for a long period of continuous operation. However, an aircraft tyre absorbs the high impact loads of landing, and also it’s operating at high speeds for a short time when required. Carcass plies are used to form the tire. They are sometimes called casing plies.

Let’s go through some technical aspects of the tyre.

Retreading – Retreading is methods of restoring a worn tyre by renewing the tread area or by renewing the tread area plus one or both sidewalls. Repairs are included in the tyre retreading process.

Load Rating – Load rating is the maximum permissible load at a specified inflation pressure.

Ply Rating – Ply Rating is used to identify the maximum recommended load rating and inflation pressure for a specified tyre. It is an index of tyre strength.

Speed Rating – The speed rating is the maximum takeoff speed to which the tyre has been tested.

Skid Depth – Skid depth is the distance between the tread surface and the deepest groove as measured in the mould.

Aircraft tyres must have an approved speed and load rating and have sufficient clearance when retracted through landing gear to allow for tyre growth. Tyre growth is the increase in the size of the tyre due to centrifugal forces at high speed.

Airecraft tyre may be with tube or tubeless:

Tubeless tyres are more advantageous over tube-type. There is no longer the use of tube-type tyre in recent aviation. Nowadays all airliners are using tubeless tyres. Tubeless that are meant to be used without a tube has the word TUBELESS on the sidewall of the tyre.

Aircraft tyre may be radial or bias:

Almost all airliners are using Radial tyre. Bias is an older design, and it’s mainly used for road vehicles. Radial tyres have the word RADIAL on the sidewall. Radial tires are more expensive than bias-ply tyres. Radial tires are in demand because of their lower life cycle cost and long term value.

Aviation tyres are conductive:

Aircraft tyres are manufactured with tread rubber with conducting compounds to permit earthing of static charges. In early days when tyres were not sufficiently conductive, aircraft used to have a conductive strip hanging down from the axle of the landing gear. Upon landing, this strip would be the first part of the aircraft to touch the earth. This discharges any static electricity accumulated on the outer surfaces of the aircraft. Now you don’t see them anymore.

ROLLING RESISTANCE:

The force that resists the motion of a body rolling on a surface is called rolling resistance or rolling friction.

The rolling resistance can be expressed as `underset(r)(F)=c**W`

c - coefficient of rolling resistance

W - weight of the body

W = `m**underset(g)(a)`

m = mass

`underset(g)(a)`= acceleration due to gravity

Note that the rolling resistance coefficient - c - is influenced by different variables like wheel design, rolling surface, wheel dimensions and tyre pressure.

The rolling resistance can alternatively be expressed as

`underset(r)(F)=underset(l)(c)**W/r`

`underset(l)(c)`=coefficient of rolling resistance (dimensions in length)

r = radius of the wheel

The rolling coefficients for air filled tires on dry roads can be estimated

c = 0.005 + (1 / p) (0.01 + 0.0095 (v / 100)²)

where

c = rolling coefficient

p = tire pressure (bar)

v = velocity (km/h)

TYRE PRESSURE:

A Boeing 777 uses 14 tires, Airbus' A380 carries 22, and the enormous Antonov An-225 demands 32. The key to their remarkable durability is maximizing the air pressure, says Lee Bartholomew, lead test engineer for Michelin Aircraft Tires. The high-flying rubber is typically inflated to 200 psi, roughly six times what you put in an automobile tire, and the tires on an F-16 fighter are pumped to 320 psi. “It's really pressurized air that's so strong,” he says. Aircraft tires are amazing when you think about it. The typical airliner tire can handle a 38-ton load. It can meet the ground 500 times before needing a re-tread, a refresh it can take on seven times in its life. The tires themselves aren't terribly large--- a Boeing 737 rides on 27x7.75 R15 rubber. In English, that means it is 27 inches in diameter, 7.75 inches wide, and wrapped around a 15-inch wheel. The sidewalls aren't terribly thick, and the strength of the tire lies in the cords embedded below the tread, Bartholomew says. They're typically nylon, and more recently a variety known as aramid. Each layer of the casing contributes to its load bearing and air pressure resisting capabilities. Of course, tires can fail, especially when under-inflated or overloaded. Treads can come off and casings can blow out. In the first moments after a plane touches down, the tires are skidding, not rolling. The airplane essentially drags them down the runway until their rotational velocity matches the velocity of the plane. That's why they smoke upon landing, and why Michelin uses grooves instead of the block patterns seen on your car's rubber---blocks would simply break off. (Most tire wear comes from this moment of contact---where the rubber meets the runway.) The stoutest tires are rated for speeds of up to 288 mph. To develop a new sort of tire, or test a tweak, Michelin starts with computer simulation, followed by prototyping. Then it tests how the tires do when they're overloaded or pushed past their speed limit, on simulated takeoffs, landings, and taxiing. Like everything in aviation, tires must meet specific and demanding rules---for example, a tire must withstand four times its rated pressure for at least three seconds.

TPMS (Tire Pressure Monitoring System): Aircraft models have TPMS sensors in their wheels. The system is very similar to the TPMS in automobiles. Cockpit displays show tire pressures for all tires equipped with the sensors.

BRAKE FORCES:

Stopping a 200-tonne aircraft landing at 180 mph requires a lot of braking force. To do this, the 787 has one brake unit on each of the eight wheels on the main gear assembly. On other aircraft types, the brake units are powered by the hydraulics system. An electrical signal is sent from the flight deck to hydraulic actuators near the main landing gear. Here, hydraulic fluid at 3,000 pound per square inch is used to force the brake unit against the wheel, thus slowing it down. This system works fine, but the pipes and actuators that form this part of the hydraulic system come at a considerable weight cost. Extra weight means more fuel burn, which in turn increases costs and carbon emissions.

Designers did away with the use of the hydraulic system and all its associated architecture and instead used electricity to power the brakes. When the pilots press on the brake pedals, an electrical signal is sent to the brake unit on the wheel. Here, electrically powered actuators are used to press the carbon brake disc against the wheel, slowing it down.

By changing to electric brakes, a 787-8 saves 141 pounds per aircraft and a 787-9 saves 245 pounds. The brakes are also known as “plug and play” because electrical wiring replaces the traditional hydraulics and it’s much easier and quicker to change the brake units when needed. Smart features also allow engineers to monitor the brake performance more closely, giving a real-time measurement of wear on the carbon disks.

ELECTRICAL BRAKE:

The brake system on the 787 Dreamliner is controlled by the pilots pressing the tops of the rudder pedals under their feet, demanding the rate of braking which they require. This sends an electric signal to the Left and Right Brake System Control Units (BSCUs).

These then send signals to the four Electronic Brake Actuator Controllers (EBAC) which control the rate of braking on the wheels. Each wheel has four Electric Brake Actuators (EBA), a kind of piston which presses against the carbon brake discs.

The brake disks themselves are made up of two parts. Firstly, there are the rotors. These are connected to the wheel by drive tabs. As these drive tabs are in contact with the inside of the wheel, they spin at the same speed. Depending on the brake manufacturer, there are either four or five of these rotors on each brake assembly.

The second part of the disks are the stators. These sit around each rotor and are fixed in place and thus don’t move. As the wheel turns, the rotors spin round inside the stators. When the brakes are applied, the four EBAs apply pressure to the first stator. This in turn squeezes the stationary stators up against the spinning rotors and it’s this friction which slows the wheel down.

ANTI-SKID PROTECTION:

When landing on slippery runways, there’s a chance that the wheels may start to skid as the brakes are applied. To stop this from happening and to maintain maximum effective braking, each wheel has anti-skid protection.

Using a variety of sources to determine the aircraft speed, the brake units know how fast the wheels should be spinning. If that speed drops significantly, it’s because the current brake pressure on that wheel is too great and the wheel is just skidding over the surface.

In this situation, the anti-skid system automatically reduces the braking on that wheel to a point where the skid stops before reapplying the pressure. All this is done in a fraction of a second.

AUTOBRAKE:

Pressing on the brakes is pretty straight forward when taxiing in a straight line at low speed. However, when we’re landing in strong winds, it can be a little tricky. We need to use our feet on the rudder pedals to line the nose of the aircraft up with the runway centerline at the last moment. Then, whilst holding that position, slide our feet up to press the toe brakes. Really not very easy when moving at 160 mph.

To help us get the braking underway as soon as we touch down, we have the autobrake system.This provides automatic braking at a preselected rate as soon as the aircraft senses that it is on the ground. It also provides full braking pressure in the case of a rejected takeoff if the speed is above 85 knots (98 mph).

In addition to the brakes, there are two other systems which help slow the aircraft down on landing. The spoilers and the reverse thrust.

SPOILERS:

Have you noticed the large panels on the top of the wings raise up on touch down? These are the called the spoilers as they literally spoil the airflow over the wing. This dumps any remaining lift the wings are generating, allowing the wheels to take all the weight and achieve maximum efficiency from the brakes.

REVERSE THRUST:

The final part of the braking process comes from reverse thrust. Just after we have touched down, we pull two levers on top of the thrust levers to engage the reverse thrust, a sort of “reverse gear” for jet engines. This causes blockers inside the engine to deploy and a door in the side of the engine to slide backward. The air which normally leaves the engine out the back is deflected forward by the blockers and out through the door. There are two stages of reverse thrust — idle reverse and max reverse. Idle reverse is used on most landings and max reverse is used when the landing performance requires it, normally when the aircraft is landing at hot or high elevation airfields. This forward directed airflow helps slow the aircraft down but is most efficient at high speeds. If using max reverse, we drop this down to idle reverse at 60 knots (70 mph) and then back to normal thrust as we vacate the runway at around 20 knots (25 mph).

6. A. With necessary assumptions, calculate the force and power required to push / pull an aircraft by a towing vehicle.

SOLUTION:

Total weight of airbus A350 = 248000kg

g=9.81 m/sec^2

co-efficient of rolling resistance Cr1 = 0.006

Drag co-efficient Cd1 = 0.5

Air densiity(`rho`) = 1.125 kg/m^3

Frontal area(A) = 150 m^2.

Velocity(V) = 7m/s

Total weight of the towing vehicle (challenger 280) = 24000Kg

Drag force and rolling resistance force of the towing vehicle is much less compared to the airbus A350. So we are neglecting them.

Rolling resistance force (Fr) = Cr1*m*g =0.006*248000*9.81=14.59KN

Drag force(Fd) = 0.5*`rho`*Cd1*A*V^2 = 0.5*1.125*0.5*150*7^2 = 2.06KN

Total resistive force(Ft) = Fr+Fd = 16.65 KN

Power required for a towing vehicle = Ft * V = 16.65 * 7 = 116.55 Kw.

B. Develop the model for the calculated force and power using Simulink.

SOLUTION:

7. A. 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.

SOLUTION:

Power required for a towing vehicle to tug a airbus A350 = 116.55 KW.

Total resistive force = 16.65 KN.

Assumption:

Tyre radius of towing vehicle = 0.762m

Torque required at the wheels = total force * radius = 16.65*0.762 = 12.68KNm

we assume gear ratio to 10 and transmission efficiency(Teff) is 80%, motor efficiency(Meff) is 90%

Motor torque = (wheel torque)/(gear ratio*Teff*Meff) = (12.68)/(10*0.8*0.9)= 1.76 KNm

Assuming 500kWh baterry

Total energy consumed = 116.55*0.1667 = 19.42KWh ( that is for 10 min)

Duty cycle = required power/rated power = 116.55/500 = 0.2.

Blockdiagram of Powertrain:

B. Also, Design the parameters in excel sheet.

LINK1:

https://drive.google.com/file/d/1pf9pmMXv2yTReBw3mXoWKpBeE0JZ_VIH/view?usp=sharing

LINK2:

https://drive.google.com/file/d/1LrgkrFrPDc0b49DFaz9_BJrIP4d8JMpL/view?usp=sharing

LINK3:

https://docs.google.com/spreadsheets/d/1NBq4lfHVHgHAkSsVNjavdXLsbxK1o7bS/edit?usp=sharing&ouid=114797374529348124033&rtpof=true&sd=true