All Courses
All Courses
Courses by Software
Courses by Semester
Courses by Domain
Tool-focused Courses
Machine learning
POPULAR COURSES
Success Stories
Problem Statement: Part A: 1. Search and list out the total weight of various types of aircrafts. 2. Is there any difference between ground speed and air speed? 3. Why is it not recommended to use aircraft engine power to move it on the ground at Airport? 4. How an aircraft is pushed to runway when its ready…
Rahul Gidaveer
updated on 26 Apr 2021
Problem Statement:
Part A:
1. Search and list out the total weight of various types of aircrafts.
2. Is there any difference between ground speed and air speed?
3. Why is it not recommended to use aircraft engine power to move it on the ground at Airport?
4. How an aircraft is pushed to runway when its ready to take off?
5. Learn about take off power, tyre design, rolling resistance, tyre pressure, brake forces when landing.
Part B:
6. A. With necessary assumptions, calculate the force and power required to push / pull an aircraft by a towing vehicle.
B. Develop the model for the calculated force and power using Simulink.
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.
(Hint :DC7 Block)
B. Also, Design the parameters in excel sheet.
Solution:
Part A:
1. Various types of aircraft:
Aircraft type | Total weight (kg) | |
1 | Helicopter | 1500 |
2 | Turboprop aircraft | 3670 |
3 | Piston Aircraft | 1157 |
4 | Light jet | 4540 |
5 | Midsize jet | 13500 |
6 | Jumbo jet | 350000 |
7 | Regional Jet | 39000 |
8 | Narrow-body aircraft | 124000 |
9 | Widebody airlines | 650000 |
10 | Commuter liner | 18000 |
11 | Airbus | 575000 |
12 | Concorde | 78700 |
13 | Tupolev Tu-144 | 85000 |
14 | Military aircraft | 381000 |
15 | Fighter | 20000 |
16 | Water bomber | 20000 |
17 | Maritime Patrol | 23000 |
18 | Multirole combat | 13000 |
19 | Transport | 6000 |
2. Difference between ground speed and air speed of an aircraft:
Airspeed | Groundspeed |
It is the speed of the aircraft relative to the airflow around the aircraft | It is the speed of an aircraft relative to the surface of earth. |
Airspeed is also the speed with which air is flowing around the aircraft body. It affects the aircraft speed in all directions | Ground speed is the horizontal speed of an aircraft and it is zero if the aircraft moves vertically. |
Airspeed determines if there is enough flow of air around aircraft body to to provide the lift force | Ground speed determines the time taken to reach the destination |
Airspeed is the difference between the aircraft speed and wind speed | Groundspeed is the sum of aircraft speed and wind speed.It |
During tailwind, airspeed is comparatively lower | During tailwind, Ground speed is aided by wind speed and it is comparatively higher |
During headwind, airspeed is higher | Headwind offers resistance to aircraft and slows down the groundspeed. |
3. Reasons for not using airplane engine to move on the ground:
4. How an aircraft is pushed to runway:
5. Aircraft design:
6. A. Force and power calculation to push an aircraft by towing vehicle:
The assumed aircraft and tow tractor are given in the excel file.
Rolling resistance, hill climb resistance, acceleration and aerodynamic drag are taken into consideration for power calculation.
The following formulae are utilized to calculate various forces:
Rolling resistance Fr=μrr⋅W;
where μrr: rolling resistance coefficient and W: is the weight of the vehicle;
Hill climb resistance: Fh=W⋅sin(θ)
where θ: angle of slope of ground and θ=tan−1(G) where G is gradeability
Acceleration a=v−ut
where v: Final velocity; u: initial velocity; t: duration of acceleration
Force Fa=m⋅awhere m: mass of vehicle
Aerodynamic drag: Fd=0.5⋅ρ⋅Cd⋅Af⋅v2
where ρis density of air; Cdis drag coefficient; Afis frontal area of vehicle; v is speed of vehicle
The power is calculated as P=F⋅vwhere F is corresponding force.
The calculations are performed in excel and the following result is obtained.
B. Simulink model for calculated force and power:
Overview of complete block:
Various subsystems to calculate different power requirements:
7. Designing an eletric powertrain for aircraft towing application and estimation of duty cycle range for aircraft on runway:
Assumed parameters:
Aircraft model | Airbus A320 |
Tow truck model | MODEL BA10G40 |
Aircraft weight | 68000 kg |
Tow truck weight | 11000 kg |
Rolling resistance coefficient of aircraft | 0.04 |
Rolling resistance coefficient of tow truck | 0.2 |
Tow truck speed while towing | 5 km/h or 1.38 m/s |
Tow truck maximum speed | 30 km/h or 8.33 m/s |
Gradeability | 2 % |
Total traction force required | 78.434 kN |
Total power required | 435 kW |
Duration of tow truck application | 1800 s or 30 min |
Wheel radius of tow truck | 0.537 m |
Torque required at the wheels: Tw=Ft⋅rw=78434⋅0.537=42119N−m
Totale≠rgyrequiredfor→w∈gapplication:E=P*t=435*0.5=217.5 kWh`; This indicates the battery capacity for tow tractor.
Selection of motor:
From the above assumed parameters and calculations of torque and power, it is inferred that tow tractor is low speed and high torque application. So the motor that best suits this application is Permanent magnet synchronous motor. This motor is capable at providing very high torque at very low speeds. Since the tow tractor is used for short duration of time, motor with forced ventilation is selected rather than water cooled. From the below list of motors, the motor with power output close to required power of 435 kW is 471 kW with positive tolerance.
This selected motor: P22F 355 L12
Motor rated torque: Tm=7500N−m
Efficiency of the motor: η=96.5%
Rated current : I=1257A
Maximum voltage : V=400V
Weight of motor: 2400 kg
Calculation of gear ratio: G=TrequiredTm=421197500≅6
Gear ratio is selected to be 6.
We know that: Ftraction=Pvw⇒Tm⋅Grw=P⋅Gωm⋅rw⇒Tm=435000ωm
The above equation is the motor characteristics.
Powertrain design:
The above figure shows the powertrain arrangement of tow tractor for towing aircraft. The battery source is displayed at the left. The battery parameters are the maximum voltage value of the selected motor. The motor characteristics is implemented as calculated above.
The tow tractor speed is put into the speed reference block parameters. Final speed value is taken as the maximum speed of tow tractor: 20 km/h. And the tow vehicle is initially in standstill position, so initial value is 0.
Duty cycle:
Duty cycle is an important parameter for the power electronics switch between the battery and motor. The motor is required to be supplied with gradually changed voltage values but if the batter is directly connected to the motor, motor receives full battery voltage and runs at rated speed instantaneously. So in order to regulate the voltage in gradual manner power electronics switches come into picture. Duty cycle is the ratio of amount of time the switches are required to be ON to the total time period (sum of ON and OFF period). Duty cycle can be calculated with the ratio of power supplied to the motor (or output power of power electronics circuit) to the power supplied by the battery (or input power to the power electronics circuit).
Required output power of the motor for towing application at highest speed of 20 km/h: Preq=435kW
Input power to the motor to obtain required output considering the losses in the motor: P=Preqηm=4350.965=450.77kW
So the output power of power electronics circuit is Po=450.77kW
Assume battery source parameters such that it is capable of providing maximum power that the selected motor can withstand. So let the maximum voltage and current values be the parameters of the battery.
Battery voltage: Vbat=400V
Battery current: Ibat=1257A
Battery power: Pbat=Vbat⋅Ibat=400⋅1257=502.8kW
So the Input power of the power electronic circuit is Pi=502.8kW
Duty cycle: D=PoPi=450.77502.8=0.896
So the duty cycle range for towing aircraft from zero to highest speed is 0% to 89.6%
B. Design parameters in excel sheet is attached.
Reference:
Leave a comment
Thanks for choosing to leave a comment. Please keep in mind that all the comments are moderated as per our comment policy, and your email will not be published for privacy reasons. Please leave a personal & meaningful conversation.
Other comments...
Week 9 - Project 1 - Door Trim Lower with Engineering Features
Introduction: When thermoplastic components are involved in the assembly, they are required to be joined with a dissimilar material. The material with which it is assembled could be a metal or a other kind of thermoplastic material. The joining is facilitated by heat staking. Thermal staking is an assembly process which…
27 Nov 2022 02:38 PM IST
Week 9 - Project - A pillar Design with Master Section
Introduction: A-pillar is an important structure of the four-wheeler vehicle. It supports the windshield and roof. It is the first pillar of the vehicle. It connects with the windshield frame, provides groove to the window and connects with the roof. In this project, Class-A surface of the A-pillar is taken as input and…
26 Nov 2022 07:00 AM IST
Week 8 - Challenge 4 - Bumper
Draft Analysis of an Automotive Bumper Plastic Component: Introduction: A bumper is an automobile's front part that shields the engine and provides housing for headlamps and defogging lamps. It is a plastic component and is manufactured by Injection Moulding Machine. Hence the component needs to be verified if it…
16 Nov 2022 03:27 PM IST
Week 9 - Attachment Feature Creation (Ribs & Screw Boss) - Challenge 1
Introduction: To create attachment features on the door handle part. The attachment features include ribs and dog houses. Procedure: 1. The image below shows the Class A surface of the door handle. Cursory look at the part reveals that the tooling axis is along the Y-direction. 2. Tooling axis is created …
24 Sep 2022 01:08 PM IST
Related Courses
0 Hours of Content
Skill-Lync offers industry relevant advanced engineering courses for engineering students by partnering with industry experts.
© 2025 Skill-Lync Inc. All Rights Reserved.