Project-1: Powertrain for aircraft in runways

Part A:

Q1.

The estimated average weights for different types of aircraft:

• Light aircraft: 1,000 kg to 2,000 kg
• Medium-sized airliner: 60,000 kg to 80,000 kg
• Large airliner: 150,000 kg to 300,000 kg

Q2.

Airspeed typically refers to two key measurements:

1. Indicated Airspeed (IAS): This is the speed shown on the aircraft's airspeed indicator. It measures the dynamic pressure of the air as the aircraft moves through it.

2. True Airspeed (TAS): This is the actual speed of the aircraft through the air mass. It is the Indicated Airspeed corrected for altitude and nonstandard temperature.

Ground speed, on the other hand, is the speed of the aircraft over the ground. It is the combination of the aircraft's True Airspeed and the effects of winds aloft. Wind can either increase or decrease ground speed compared to True Airspeed, which remains relatively constant.

In summary, while airspeed is the speed of an aircraft through the air mass, ground speed is the speed of the aircraft over the ground, taking into account the effects of wind.

Q3.

Using aircraft engine power to move an aircraft on the ground at an airport is generally discouraged for several reasons:

• Fuel Efficiency: Aircraft engines are designed to be most efficient at high altitudes and speeds. Using them for ground movement can result in unnecessary fuel consumption.
• Wear and Tear: Excessive use of the engines on the ground can lead to increased wear and tear on the engines, reducing their lifespan and potentially leading to maintenance issues.
• Noise and Emissions: Running aircraft engines on the ground can contribute to noise pollution and emissions, impacting both the environment and the surrounding community.
• Safety: Aircraft engines are powerful and can create jet blasts and turbulence, posing risks to ground personnel, other aircraft, and infrastructure when operated at high power levels on the ground.
• Due to these reasons, most airports have designated ground vehicles, such as tugs or pushback vehicles, to safely move aircraft on the ground without the need for using the aircraft's engines.

Q4.

When an aircraft is ready to take off and needs to be moved from the apron or gate to the runway, it is typically pushed back by a specialized ground support vehicle called a pushback tug. Here's how the process generally works:

• Preparation: The ground crew connects the pushback tug to the nose landing gear of the aircraft using a towbar. The tug is then operated by a trained ground crew member.
• Pushback: The pushback tug slowly pushes the aircraft backward away from the gate or parking stand. The pilot and ground crew communicate via radio or hand signals to ensure a safe and coordinated movement.
• Taxiing: Once the aircraft is clear of the gate area, the tug continues to push the aircraft along the taxiway towards the assigned runway. The ground crew follows proper taxiing procedures and instructions from the air traffic control tower.
  
• Handover: Once the aircraft reaches the designated holding point at the runway, the pushback tug disconnects from the aircraft, and the pilot takes over control for taxiing onto the runway.
  
• This process allows for controlled and safe movement of the aircraft on the ground, ensuring that it reaches the runway ready for takeoff in a timely and efficient manner.

Q5.

• During takeoff, aircraft engines provide thrust to propel the aircraft down the runway and into the air. Takeoff power is the maximum power setting used during this phase to achieve the necessary speed for the aircraft to lift off.
• Tyre design on aircraft is critical for withstanding the high loads, speeds, and temperatures experienced during takeoff and landing. Aircraft tyres are made of specialized rubber compounds and constructed to be robust yet flexible. They are designed to dissipate heat efficiently, provide good traction, and withstand high-speed rotations.
• Rolling resistance is the force that resists the movement of the aircraft tyres as they roll along the runway during takeoff and landing. Factors affecting rolling resistance include tyre design, tire pressure, runway surface condition, and aircraft weight. Reducing rolling resistance is important for fuel efficiency and overall performance.
• Tyre pressure is carefully monitored and controlled to ensure safe and optimal operation. Proper tyre pressure is essential for load distribution, braking efficiency, and overall tyre performance. Tyre pressure is usually higher than that of tires on vehicles to support the weight of the aircraft and withstand heavy loads and high speeds.
• When an aircraft lands, brake forces are applied to slow down and stop the aircraft. The aircraft's braking system, typically consisting of hydraulic brakes, is responsible for generating the necessary braking force. Factors such as aircraft weight, landing speed, runway conditions, and braking system conditions influence the effectiveness of the brakes in bringing the aircraft to a safe stop after landing.
• Overall, takeoff power, tyre design, rolling resistance, tyre pressure, and brake forces are crucial elements in ensuring safe and efficient aircraft operations during the takeoff and landing phases.

Q6A.

• From the scope result, we can see that when two IGBTs 1 & 4 are ON then armature fluctuated more with higher amplitude means high value of armature voltage.
• at that time, the armature cure current remains +ve which states that motor is in loaded conditions.
• Motor speed also increases & +ve.
• then when 2 & 3 IGBTs are ON, then armature voltages flactuate but with lower amplitude so we can say that voltage value becomes low.
• at that time, armature currents starts decreasing & becomes -ve which states that motor is in either charging or in regenerative conditions.
• Speed also become -ve which states that it motor charges it's direction of rotating & acts as generator.