Project-1: Powertrain for aircraft in runways
PART A
1) Search and List Out the Total Weight of Various Types of Aircrafts
Understanding the total weight of aircraft is crucial in aviation, influencing both construction and operational efficiency. Excessive weight compromises aircraft performance and safety margins, particularly during emergencies. The maximum take-off weight (MTOW) represents the maximum mass an aircraft can safely lift off due to structural and operational constraints.
Aircraft Weight Data:
Antonov An-225: 640,000 kg
Scaled Composites Model 351 Stratolaunch: 589,670 kg
Airbus A380-800: 575,000 kg
Boeing 747-8F: 447,700 kg
Boeing 747-8: 443,613 kg
Boeing 747-400ER: 412,770 kg
Douglas DC-8-32: 140,000 kg
Tupolev Tu-154M: 104,000 kg
Bombardier Q400: 28,000 kg
ATR 42-500: 18,600 kg
BAe Jetstream 41: 10,890 kg
Learjet 75: 9,752 kg
Cessna Citation CJ4: 7,761 kg
Notes:
MTOW - represents the maximum weight limit for takeoff.
MLW (Maximum Landing Weight) - is another critical parameter, ensuring safe landing operations.
2) Is There Any Difference Between Ground Speed and Air Speed?
Understanding the distinction between ground speed and airspeed is vital in aviation navigation and performance assessment.
For Visualisation purporse by NASA:
https://www.grc.nasa.gov/www/k-12/airplane/Animation/airrel/anrelg.html
Ground Speed:
l Definition: The horizontal speed of an aircraft relative to the ground.
l Calculation: Ground speed accounts for the vector sum of true airspeed and wind speed. Headwinds subtract from ground speed, while tailwinds add to it.
l Influence: Wind direction and velocity impact ground speed, affecting flight time and fuel efficiency.
Airspeed:
l Definition: The relative velocity between an aircraft and the surrounding air.
l Calculation: Airspeed is derived from ground speed and wind speed. It determines aerodynamic performance and lift generation.
l Impact: Airspeed variations influence aircraft stability, control, and maneuverability during flight operations.
3)Why Is It Not Recommended to Use Aircraft Engine Power to Move It on the Ground at Airports?
Utilizing aircraft engine power for ground movement poses various safety and operational risks, prompting industry recommendations against the practice.
Reasons Against Engine-Powered Ground Movement:
l Terminal Damage Risk: Engine exhaust, known as jet blast, can cause structural damage to terminal buildings and ground equipment due to high-velocity airflow.
l Foreign Object Ingestion: Engines close to the ground may inhale sand and debris, potentially causing engine damage and operational disruptions.
l Loss of Control: High-power engine operation on the ground increases the risk of aircraft movement mishaps, endangering personnel and equipment.
l Visibility Challenges: Aircraft pilots have limited visibility from the cockpit, making it challenging to maneuver safely on the ground, unlike dedicated ground support personnel.
l Fuel Efficiency: Engine-powered ground movement consumes unnecessary fuel, contributing to operational costs and environmental impact.
l Noise Pollution: Multiple aircraft generating engine noise simultaneously can disturb passengers, airport staff, and nearby residents.
4) How Is an Aircraft Pushed to the Runway When It's Ready to Take Off?
Aircraft taxiing to the runway for takeoff involves precise ground movement procedures and equipment.
Taxiing Process:
Definition: Taxiing refers to the movement of an aircraft on the ground under its own power, facilitated by its wheels or landing gear.
Methods:
l Independent Taxiing: Aircraft navigate taxiways under their own power, controlled by pilots or ground personnel.
l Tow Tugs: Larger aircraft may require tow tugs or tractors for ground movement, especially in congested airport environments.
l Safety Measures: Pilots follow designated taxi routes, guided by ground control instructions and airport signage, ensuring safe navigation amidst other aircraft and ground vehicles.
l Regulations: Taxiing operations adhere to airport regulations and standard operating procedures to minimize collision risks and maintain operational efficiency.
5) Learn About Takeoff Power, Tyre Design, Rolling Resistance, Tyre Pressure, and Brake Forces When Landing.
Understanding key aspects of aircraft operations enhances safety and performance across various flight phases.
Takeoff Power:
l Calculation: Takeoff power determination involves balancing thrust, aerodynamic drag, and rolling resistance to achieve safe acceleration and lift-off.
l Critical Factors: Safe flying speed (V), thrust-to-weight ratio, and runway length influence takeoff performance and power requirements.
Tyre Design:
l Function: Aircraft tyres endure heavy loads during landing, takeoff, and taxiing, requiring robust design features for stability, traction, and impact resistance.
l Construction: Radial and bias-ply tyre designs offer distinct advantages in load-bearing capacity, flexibility, and puncture resistance.
l Performance: Tyre tread patterns optimize grip, water dispersion, and braking efficiency, ensuring safe ground operations in various weather conditions.
Tyre Pressure:
l Importance: Proper tyre inflation maintains structural integrity, load-bearing capacity, and operational safety during ground movements.
l Considerations: Aircraft tyres operate under extreme pressure, temperature, and load conditions, requiring regular maintenance and inflation monitoring to prevent failures.
Rolling Resistance:
l Definition: Rolling resistance refers to the force opposing motion when a wheel or tyre rolls on a surface, impacting aircraft taxiing and landing operations.
l Calculation: Rolling resistance depends on tyre construction, surface condition, and applied load, influencing fuel consumption and brake wear.
Brake Forces During Landing:
l Deceleration Devices: Spoilers, wheel brakes, and reverse thrust systems contribute to effective aircraft deceleration during landing, ensuring safe touchdown and runway exit.
l Safety Features: Anti-skid systems prevent wheel lock-ups, enhancing braking efficiency and directional control on various runway surfaces and weather conditions.
PART B
6A) Calculate the Force and Power Required to Push/Pull an Aircraft by a Towing Vehicle.
Ground movement of aircraft involves precise force and power calculations for safe and efficient operations.
Force and Power Calculation:
l Forces Involved: Thrust, aerodynamic drag, rolling resistance, and gradient resistance determine the total force required for aircraft towing.
l Power Requirement: Power calculations involve multiplying the total force by the velocity of towing, considering operational constraints and safety margins.
l Assumptions: Assumed parameters include aircraft mass, rolling resistance coefficient, drag coefficient, air density, frontal area, and towing velocity.
Rolling Resistance (Frr):
Coefficient of rolling resistance (Crr) = 0.002 (on tarmac)
Rolling resistance force is given by Frr = Crr ⋅ m ⋅g
For the aircraft:
Frr = 0.002 ⋅ 575000 ⋅ 9.81 ⇒ Frr = 11281.5 N ⇒ Frr = 11.2815 kN
For the Towing Vehicle: Frrt = 0.002 ⋅ 1000 ⋅ 9.81 ⇒ Frrt = 19.62 N
As the towing vehicle resistance is so less compared to the Aircraft because this is a heavy aircraft these can be neglected
Aerodynamic resistance (Far):
Drag coefficient (Cd): 0.025
Air Density ( ρ ) = 1.125kg/m^3
Frontal Area (A): 150m^2.
Velocity (v) = 14.5kmph or 4m/s
Far = 1/2 ⋅C d ⋅ρ ⋅A ⋅v2
Far = 1/2 ⋅ 0.025 ⋅1.125 ⋅150 ⋅ 4 2 ⇒ 33.75 N
As the vehicle and Plane is moving at very low speed Aerodynamic resistance can be neglected
Hill Climb Resistance:
Runways are constructed flat so Gradient resistance/ hill climb force is neglected.
Total Resistance:
F t = 11.2815 k N
Power Required:
P = F t ⋅ v ⇒ P = 11.2815 ⋅ 4 ⇒ 45.26 kW
The min power required by the tow vehicle is 45.26kW to taxi a heavy air craft at 4m/s.
6B) Simulink Model:
l Components: Simulink model integrates input parameters, force calculations, and power requirements, providing a visual representation of towing dynamics.
l Visualization: Display blocks visualize force components, power output, and system performance, aiding in model analysis and optimization.
7A) Design an Electric Powertrain for Aircraft Towing Application in Simulink.
Electric powertrains offer sustainable and efficient solutions for aircraft ground movement, requiring careful design and integration for optimal performance.
Electric Powertrain Design:
l Motor Selection: REB 90 electric motor offers suitable power output and torque characteristics for aircraft towing applications, ensuring efficient ground movement.
l Voltage Considerations: Battery voltage selection and correction factors influence motor performance and duty cycle, balancing power requirements and operational efficiency.
l Duty Cycle Estimation: Duty cycle calculations based on motor and battery specifications estimate powertrain efficiency and energy consumption during towing operations.
Assumed Parameters Table:
|
Parameter |
Value |
|
Aircraft Mass |
575,000 kg |
|
Pushback Truck Mass |
1,000 kg |
|
Rolling Resistance Coefficient |
0.002 |
|
Drag Coefficient |
0.025 |
|
Air Density |
1.125 kg/m^3 |
|
Frontal Area |
150 m^2 |
|
Towing Velocity |
4 m/s |
|
Battery Voltage |
550 V |
|
Correction Factor |
0.8 |
Block Diagram:
Included a visual representation of the powertrain components and their connections in a block diagram format.
Simulink Model:
Input:
Output:
From the motor:
From the Battery:
7B) Design Parameters Excel Sheet:
Excel Sheet:
Provided as attachment to the Excel sheet containing the design parameters and calculations for reference and analysis.
Conclusion:
In conclusion, this project provided a comprehensive understanding of various aspects related to aircraft operations, ground movement, and powertrain design for towing applications.