Project-1: Powertrain for aircraft in runways

Part A

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

An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines. Common examples of aircraft include airplanes, helicopters, airships (including blimps), gliders, paramotors, and hot air balloons. The human activity that surrounds aircraft is called aviation. The science of aviation, including designing and building aircraft, is called aeronautics. Crewed aircraft are flown by an onboard pilot, but unmanned aerial vehicles may be remotely controlled or self-controlled by onboard computers. Aircraft may be classified by different criteria, such as lift type, aircraft propulsion, usage and others.

Type	MTOW [kg]	MLW [tonnes]	TOR [m]	LR [m]	ICAO category	FAA category
Antonov An-225	6,40,000	591.7	3,500		Heavy	Super
Scaled Composites Model 351 Stratolaunch	5,89,670		3,660		Heavy	Super
Airbus A380-800	5,75,000	394	3,100	1,930	Heavy	Super
Boeing 747-8F	4,47,700	346.091	3,100	1,800	Heavy	Heavy
Boeing 747-8	4,43,613	306.175	3,100		Heavy	Heavy
Boeing 747-400ER	4,12,770	295.742	3,090		Heavy	Heavy
Antonov An-124-100M	4,05,060	330	2,520	900	Heavy	Heavy
Boeing 747-400	3,96,900	295.742	3,018	2,179	Heavy	Heavy
Lockheed C-5 Galaxy	3,81,000	288.417	2,530	1,494	Heavy	Heavy
Boeing 747-200	3,77,840	285.7	3,338	2,109	Heavy	Heavy
Boeing 747-300	3,77,840	260.32	3,222	1,905	Heavy	Heavy
Airbus A340-500	3,71,950	240	3,050	2,010	Heavy	Heavy
Airbus A340-600	3,67,400	256	3,100	2,100	Heavy	Heavy
Boeing 777F	3,47,800	260.816	2,830		Heavy	Heavy
Boeing 777-300ER	3,51,800	251.29	3,100		Heavy	Heavy
Boeing 777-200LR	3,47,450	223.168	3,000		Heavy	Heavy
Boeing 747-100	3,40,200	265.3			Heavy	Heavy
Airbus A350-1000	3,08,000	233.5			Heavy	Heavy
Boeing 777-300	2,99,370	237.683	3,380		Heavy	Heavy
Boeing 777-200ER	2,97,550	213	3,380	1,550	Heavy	Heavy
Airbus A340-300	2,76,700	190	3000	1926	Heavy	Heavy
McDonnell Douglas MD-11	2,73,300	185	2,990	1,890	Heavy	Heavy
Airbus A350-900	2,70,000	175	2,670	1,860	Heavy	Heavy
Ilyushin Il-96M	2,70,000	195.04	3,115	2,118	Heavy	Heavy
McDonnell Douglas DC-10	2,56,280	183	2,990	1,890	Heavy	Heavy
Boeing 787-9	2,54,000	192.777	2,900		Heavy	Heavy
Boeing 787-10	2,54,000	201.849			Heavy	Heavy
Airbus A340-200	2,53,500	181	2990		Heavy	Heavy
Airbus A330-900	2,51,000	191	3,100		Heavy	Heavy
Ilyushin IL-96-300	2,50,000	175	2,600	1,980	Heavy	Heavy
Airbus A330-300	2,42,000	185	2500	1750	Heavy	Heavy
Airbus A330-200	2,42,000	180	2,220	1,750	Heavy	Heavy
Lockheed L-1011-500	2,31,300	166.92	2,636		Heavy	Heavy
Boeing 787-8	2,28,000	172.365	3,300	1,695	Heavy	Heavy
Lockheed L-1011-200	2,11,400				Heavy	Heavy
Ilyushin IL-86	2,08,000	175			Heavy	Heavy
Boeing 767-400ER	2,04,000	158.758	3,414		Heavy	Heavy
Airbus A300-600R	1,92,000	140	2,385	1,555	Heavy	Heavy
Boeing 767-300ER	1,87,000	136.08	2,713	1,676	Heavy	Heavy
Concorde	1,85,000	111.1	3,440	2,220	Heavy	Heavy
Airbus A300-600	1,63,000	138	2,324	1,536	Heavy	Heavy
Boeing 767-300	1,59,000	136.078	2,713	1,676	Heavy	Heavy
Airbus A310-300	1,57,000	124	2,290	1,490	Heavy	Heavy
Vickers VC10	1,52,000	151.9			Heavy	Heavy
Boeing 707-320B	1,51,000	97.5			Heavy	Heavy
Boeing 707-320C	1,51,000	112.1			Heavy	Heavy
Douglas DC-8-61	1,47,000				Heavy	Heavy
Airbus A310-200	1,42,000	123	1,860	1,480	Heavy	Heavy
Airbus A400M	1,41,000	122	980	770	Heavy	Heavy
Douglas DC-8-32	1,40,000				Heavy	Heavy
Douglas DC-8-51	1,25,000				Medium	Large
Boeing 757-300	1,24,000	101.6	2,550	1,750	Medium	Large
Boeing 707-120B	1,17,000	86.3			Medium	Large
Boeing 757-200	1,16,000	89.9	2,347	1,555	Medium	Large
Boeing 720B	1,06,000	79.5			Medium	Large
Boeing 720	1,04,000	79.5			Medium	Large
Tupolev Tu-154M	1,04,000	80			Medium	Large
Tupolev Tu-204SM	1,04,000	87.5	2,250		Medium	Large
Convair 880	87,500				Medium	Large
Boeing 737-900	85,000	66.36	2,500	1,704	Medium	Large
Boeing 737-900ER	85,000	71.35	2,804	1,829	Medium	Large
Boeing 727-200 Advanced	84,000	70.1			Medium	Large
Airbus A321-100	83,000	77.8	2,200	1,540	Medium	Large
Boeing 737-800	79,000	65.32	2,308	1,634	Medium	Large
Boeing 727-200	78,000	68.1			Medium	Large
McDonnell-Douglas MD-83	73,000	63.28			Medium	Large
Boeing 727-100	72,500	62.4			Medium	Large
Boeing 727-100C	72,500	62.4			Medium	Large
McDonnell-Douglas MD-90-30	71,000	64.41	2,165	1,520	Medium	Large
de Havilland Comet 4	70,700				Medium	Large
Boeing 737-700	70,000	58.06	1,921	1,415	Medium	Large
Airbus A320-100	68,000	66	1,955	1,490	Medium	Large
Boeing 737-400	68,000	54.9	2,540	1,540	Medium	Large
de Havilland Comet 3	68,000				Medium	Large
Boeing 377	67,000				Medium	Large
Boeing 737-600	66,000	54.66	1,796	1,340	Medium	Large
Airbus A220-300	65,000	57.61	1,890	1,494	Medium	Large
Hawker Siddeley Trident 2E	65,000				Medium	Large
Airbus A319[18]	64,000	62.5	1,850	1,470	Medium	Large
Boeing 737-300	63,000	51.7	1,939	1,396	Medium	Large
Boeing 737-500	60,000	49.9	1,832	1,360	Medium	Large
Airbus A220-100	59,000	50.8	1,463	1,356	Medium	Large
Airbus A318	59,000	57.5	1,375	1,340	Medium	Large
Boeing 717-200HGW	55,000	47.174	1,950		Medium	Large
Douglas DC-7	55,000				Medium	Large
de Havilland Comet 2	54,000				Medium	Large
Boeing 717-200BGW	50,000	46.265	1,950		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	48,000	43	2,056	1,323	Medium	Large
Caravelle III	46,000				Medium	Large
Fokker 100	46,000	39.95	1,621	1,350	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	37,500	32.8	2,244	1,304	Medium	Large
Bombardier CRJ900	36,500	33.345	1,778	1,596	Medium	Large
Embraer 170	36,000	32.8	1,644	1,274	Medium	Large
Bombardier CRJ700	33,000	30.39	1,564	1,478	Medium	Large
Douglas DC-4	33,000				Medium	Large
Vickers Viscount 800	30,400				Medium	Large
Bombardier Q400	28,000	28.01	1,219	1,295	Medium	Large
Bombardier CRJ200	23,000	21.319	1,918	1,479	Medium	Large
ATR 72-600	22,800	22.35	1,333	914	Medium	Large
Saab 2000	22,800	21.5	1,300		Medium	Large
Embraer ERJ 145	22,000	19.3	2,270	1,380	Medium	Large
ATR 42-500	18,600	18.3	1,165	1,126	Medium	Small
Saab 340	13,150	12.93	1,300	1,030	Medium	Small
Embraer 120 Brasilia	11,500	11.25	1,560	1,380	Medium	Small
BAe Jetstream 41	10,890	10.57	1,493	826	Medium	Small
Learjet 75	9,752	8.709	1,353	811	Medium	Small
Pilatus PC-24	8,300	7.665	893	724	Medium	Small
Embraer Phenom 300	8,150	7.65	956	677	Medium	Small
Beechcraft 1900D	7,765	7.605	1,036	853	Medium	Small
Cessna Citation CJ4	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

MTOW = Maximum take-off weight, MLW = Maximum landing weight, TOR = Take-off run (SL, ISA+15°, MTOW), LR = Landing run (SL, ISA+15°, MLW)

Q: Is there any difference between ground speed and air speed?

Ground speed: The aircraft moves relative to the reference point at the ground speed. Ground speed is also a vector quantity so a comparison of the ground speed to the wind speed must be done according to rules for vector comparisons.

Air speed: The important quantity in the generation of lift is the relative velocity between the object and the air. Airspeed cannot be directly measured from a ground position, but must be computed from the ground speed and the wind speed. Airspeed is the vector difference between the ground speed and the wind speed.

Airspeed = Ground Speed - Wind Speed

On a perfectly still day, the airspeed is equal to the ground speed. But if the wind is blowing in the same direction that the aircraft is moving, the airspeed will be less than the ground speed.

While ground speed is the airplane’s speed relative to the surface of the Earth, airspeed – at least true airspeed – is its speed relative to the air it is flying in.

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

High engine thrust during maintenance activity can cause considerable damage to airplanes and other elements in the airport environment. An example of this problem occurred after an airplane arrived at its final destination with a log entry indicating the flight crew had experienced anomalous engine operation. Subsequent evaluation resulted in replacement of an engine control component, followed by an engine test and trim run to verify proper engine operation. The airplane was positioned on an asphalt pad adjacent to a taxiway, with the paved surface extending from the wingtips aft to the empennage. During the high- power portion of the test run, a 20- by 20-ft (6.1- by 6.1-m) piece of the asphalt immediately aft of the engine detached and was lifted from the pad surface. This 4-in (10.2-cm)-thick piece of asphalt drifted up and into the core area of the left engine exhaust wake, where it shattered into numerous smaller pieces. The pieces were driven aft at substantial velocity, striking the aft fuselage and left outboard portion of the horizontal tail. The maintenance crew was alerted to the ramp disintegration and terminated the engine run. Subsequent inspection found that the outboard 4 ft (1.2 m) of the left horizontal stabilizer was missing, as was the entire left elevator. Corrective action included replacing the stabilizer and left elevator and repairing holes in the fuselage.

The aircraft manufacturer has to run tests on the same and has to make sure the aircraft can land on a single engine.

Some of the issues the pilot may face.

1. Change in the aerodynamic centre of the aircraft as thrust generated will be predominantly from one side of the aircraft.
2. More usage of the rudders and ailerons on the opposite side of the damaged engine. He has to be careful not to overload these control surfaces.
3. Ensure the working engine is functioning in optimal and risk free range. Damage to this engine also would be catastrophic.
4. Change in flight plan and fuel consumption. This has to be immediately communicated to ATC and nearest diversionary airfield should be approached

Q: How an aircraft is pushed to runway when its ready to take off?

Airplanes have engines, and they can use them to move forward along the ground. So they push themselves to the runway.

It is true that most of the time, a small vehicle is needed to push the larger commercial airplanes backwards away from the terminal building, because even if a plane can reverse it’s thrust, it’s not always safe to hit the buildings with that reverse thrust. So the little trucks push the bigger planes back away from the buildings, but after that, the planes can apply a small amount of engine power to roll forward just as all airplanes can.

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

Take off power: The amount of power that an engine is allowed to produce for a limited period of time for take-off. The use of take-off power is usually limited to 5 min for reciprocating engines and upto 2 and half min for gas turbine engines.

That can be anything from “use full throttle for takeoff” to a textbook on calculating what to set, sometimes augmented with software for the purpose.

On really big airplanes, you don’t just use full throttle because that is incredibly expensive, both in fuel you didn’t have to burn and in engine maintenance. Not to mention being uncomfortable and making a lot of unnecessary noise. So there is a formula that gives the correct power setting for an acceptable safety margin, given the weight of the airplane, the weather, the runway length and conditions, and possibly other factors

Tyre design: When it comes to safety, tyres are one of the most important components of aircraft. They help to absorb the shock of landing and provide cushioning. It also provides the necessary traction for braking and stopping of an aircraft.

An aircraft tyre is designed to withstand extremely heavy loads while landing, take off, taxing, and parking. The number of wheels required for aircraft increases with the weight of the aircraft, as the weight of the aeroplane needs to be distributed more evenly.

Rolling resistance: Rolling resistance, sometimes called rolling friction or rolling drag, is the force resisting the motion when a body (such as a ball, tire, or wheel) rolls on a surface. It is mainly caused by non-elastic effects; that is, not all the energy needed for deformation (or movement) of the wheel, roadbed, etc., is recovered when the pressure is removed. Two forms of this are hysteresis losses (see below), and permanent (plastic) deformation of the object or the surface (e.g. soil). Note that the slippage between the wheel and the surface also results in energy dissipation. Although some researchers have included this term in rolling resistance, some suggest that this dissipation term should be treated separately from rolling resistance because it is due to the applied torque to the wheel and the resultant slip between the wheel and ground, which is called slip loss or slip resistance. In addition, only the so-called slip resistance involves friction, therefore the name "rolling friction" is to an extent a misnomer.

Analogous with sliding friction, rolling resistance is often expressed as a coefficient times the normal force. This coefficient of rolling resistance is generally much smaller than the coefficient of sliding friction.

Tyre pressure: An aircraft tire or tyre is designed to withstand extremely heavy loads for short durations. The number of tires required for aircraft increases with the weight of the aircraft, as the weight of the airplane needs to be distributed more evenly. Aircraft tire tread patterns are designed to facilitate stability in high crosswind conditions, to channel water away to prevent hydroplaning, and for braking effect. Aircraft tires also include fusible plugs (which are assembled on the inside of the wheels), designed to melt at a certain temperature. Tires often overheat if maximum braking is applied during an aborted takeoff or an emergency landing. The fuses provide a safer failure mode that prevents tire explosions by deflating in a controlled manner, thus minimizing damage to aircraft and objects in the surrounding environment.

Brake forces when landing: Aircraft brakes stop a moving aircraft by converting its kinetic energy to heat energy by means of friction between rotating and stationary discs located in brake assemblies in the wheels. Brakes provide this critical stopping function during landings to enable airplanes to stop within the length of the runway. They also stop aircraft during rejected takeoff events, in which an attempted takeoff is canceled as the airplane is rolling down the runway before it lifts off from the ground due to engine failure, tire blowout, other system failure or direction from air traffic control.

Part B

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

Assumptions: Mass of the aircraft (m_a) = 48000kg, Coefficient of rolling resistance (μ_r) = 0.03, Acceleration due to gravity (g) = 9.81ms^-2 Frontal area of an aircraft (A) = 85m² Final velocity of the aircraft (v_f) = 3m/s, Initial velocity of the aircraft (u_i) = 0m/s, Coefficient of drag of an aircraft (c_d) = 0.15, Density of air (ρ) = 1.225 kg/m³ Acceleration time of the aircraft (t_a) = 10seconds

Rolling resistance force is Frr=μ_r m g

where, μ_r = coefficient of rolling resistance, m = Total mass of the vehicle (kg), g = Acceleration due to gravity (m/s²)

F_rr = μ_r m g

F_rr = 0.03 x 48000 x 9.81

F_rr (a) = 14126.4N

Therefore the rolling resistance force is 14126.4N

F=m*a where, m is mass and a is acceleration

F= m x (vf – v_i) / t

F= 48000 x ( 3 – 0) / 10

F= 48000 x 3 / 10

F= 4800 x 3

F(a)= 14400N

The acceleration force of the aircraft is 14400N

Aerodynamic drag force is represented by the formula:

F_d = ½ x ρ x A x c_{d x} v²

where, Ρ = Density of air (kg/m³), A = Frontal area ( m ²), c_d = Drag coefficient, v² = Velocity (m/s)

F_d = ½ x ρ x A x c_{d x} v²

F_d = ½ x 1.225 x 85 x 0.15 x 3²

F_d (a) = 70.284

The aerodynamic drag force experienced by the aircraft when it moves on the ground is 70.284N

Mass of the Towing vehicle (m_a) = 8000kg, Coefficient of rolling resistance (μ_r) = 0.013, Acceleration due to gravity (g) = 9.81ms^-2 , Frontal area of the Towing vehicle (A) = 8m² , Final velocity of the Towing vehicle (v_f) = 3m/s, Initial velocity of the Towing vehicle (u_i) = 0m/s, Coefficient of drag of the towing vehicle (c_d) = 0.60, Density of air (ρ) = 1.225 kg/m, Acceleration time of the towing vehicle (t_a) = 10seconds

Rolling resistance force F_rr = μ_r m g

F_rr = 0.013 X 8000 X 9.81

F_rr (t) = 1020.24N

The rolling resistance force between the towing vehicle wheels and tarmac road is 1020.24N

F= m x a

F= m x (vf – v_i) / t

F= 8000 x ( 3 – 0) / 10

F= 8000 x 3 / 10

F= 800 x 3

F(t) = 2400N

The acceleration force of the Towing vehicle is 2400 N

F_d = ½ x ρ x A x c_{d x} v²

F_d = ½ x 1.225 x 8 x 0.60 x 3²

F_d (t)= 26.46N

The aerodynamic drag force experienced by the Towing vehicle when it moves on the ground is 26.46N

To calculate the total tractive force required, we need to add all the forces obtained

F_{T =} F_rr (a) + F(a) + F_d (a) + F_rr (t) + F(t) + F_d (t)

F_{T =} 14274+14550+70.284+1020.24+2400+26.46

F_{T =} 32340.984N

F_{T =} 32.340984KN

Power required to push/pull aircraft is P = F_T * V

P = 32340.984*3

P = 97022.952W

P = 97.022952KW

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

Using constant block, square block, divide block, add block and display we have obtained the simulink model from the above equations

the ouput of the simulink block is

Q: 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)

Assumptions of aircraft: Mass of the aircraft (m_a) = 48000kg, Coefficient of rolling resistance (μ_r) = 0.03, Acceleration due to gravity (g) = 9.81ms^-2 Frontal area of an aircraft (A) = 85m² Final velocity of the aircraft (v_f) = 3m/s, Initial velocity of the aircraft (u_i) = 0m/s, Coefficient of drag of an aircraft (c_d) = 0.15, Density of air (ρ) = 1.225 kg/m³ Acceleration time of the aircraft (t_a) = 10seconds

Assumptions towing vehichle: Mass of the Towing vehicle (m_a) = 8000kg, Coefficient of rolling resistance (μ_r) = 0.013, Acceleration due to gravity (g) = 9.81ms^-2 , Frontal area of the Towing vehicle (A) = 8m² , Final velocity of the Towing vehicle (v_f) = 3m/s, Initial velocity of the Towing vehicle (u_i) = 0m/s, Coefficient of drag of the towing vehicle (c_d) = 0.60, Density of air (ρ) = 1.225 kg/m, Acceleration time of the towing vehicle (t_a) = 10seconds

Power required to push/pull aircraft is 97.022952KW and total tractive force is 32340.984N.

Torque (T)= F_{r *} r /G

T = 32340.984 * 0.4 / 10

T = 1293.63 Nm

Motor specifications are output power – 110 KW, 150 hp, full load speed – 740 rpm, full load Efficiency – 94.5%, full load current – 210A, full load Torque – 1420 Nm, rated voltage – 400V/50 Hz

P_{i =} V * I

P_{i =} 400 *280

P_{i =} 112000W = 112KW

duty cycle = P_o / P_i

duty cycle = 97.02 / 112 = 0.866

Therefore, duty cycle is 86%

Energy (E) = P_o * t = 97.02 * 300

E = 29106kJ

To convert energy KJ to KWH we divide it by 3600

E = 29106/3600 = 8.08KW

Simulink of DC7 block