News Excerpt:

Recently, Physics of Fluids, a journal by the American Institute of Physics, published a research paper that explored the aerodynamic performance of nylon shuttles at different flight speeds.

Key highlights of the study:

• Researchers studied how airflow and speed can deform the flared skirt of the shuttle.
• This will open up the possibility for improved designs that can make the nylon shuttle stiffer, helping it accurately mimic a feather shuttle’s aerodynamic performance.
• Studying the relative trajectory and drag on the two types of shuttles, by examining aerodynamic forces on the shuttlecock as well as its deformations at each flight speed, they noticed patterns in nylon that are different from natural feathers. 
• The outermost skirt of nylon shuttles tends to be flimsy and deforms inwards, upto 9 mm, asymmetrically. 
• With reduced air resistance, the speed gets wild and uncontrollable.
• The study also showed a process of buckling, where the shuttle sways vertically after 40 mps and the skirting starts getting rumpled. 
• Nylon shuttles buckle at 40 mps, then become an unstable square shape. 
• Then they start vibrating radially and finally travel in a wave form. That’s wobbly and not very good to play.

Key differences between nylon or synthetic shuttles and those made of goose or duck feathers:

• Feather Shuttle:

• • A feather shuttle is brittle and becomes useless after a few shots. 
    • But it holds its shape longer than nylon. 
    • There is the issue of cruelty to animals as well.
    • Duck shuttles stay stiff no matter what speed they are subjected to because the coefficient of drag doesn’t vary.

• Nylon Shuttle:

• • There is a move to get in nylon shuttles from a sustainability point of view. 
  • The aerodynamics are hugely different as the it gets deformed in shape faster and turns too wobbly to continue playing. 
    • In a nylon shuttle, the air resistance is much less, and it starts becoming unstable as it deforms.
    • The speed increases so much that opponents have very little reaction time.

• • Synthetic shuttles have high drag due to a pressure difference. Seventy-five per cent of the drag comes from the outer skirt. 

• • The centre of pressure in nylon shuttles is distributed more towards the cork, compared to a duck shuttle, where it’s towards the feathers.
  • A process of buckling, where the shuttle sways vertically after 40 mps and the skirting starts getting rumpled. “Nylon shuttles buckle at 40 mps, then become an unstable square shape. Then they start vibrating radially and finally travel in a wave form. That’s wobbly and not very good to play.

About the newly made shuttle:

• A shuttle typically weighs 5 grams - the cork makes up 1.5 grams and the skirt 3.5 grams. 
• The pressure on a nylon shuttle at speed above 40 metres per second (mps) forces it to lose shape, altering its flight behavior as the vortex structure weakens. 
• For context, shuttle speeds easily reach 300 mph.

Concept of Aerodynamics:

• Aerodynamics is the way objects move through air. The rules of aerodynamics explain how an aeroplane is able to fly. 
• Anything that moves through air is affected by aerodynamics, from a rocket blasting off, to a kite flying. 
  • Since they are surrounded by air, even cars are affected by aerodynamics.

• Four Forces of Flight:

• • The four forces of flight are lift, weight, thrust and drag. 
  • These forces make an object move up and down, and faster or slower. 
  • The amount of each force compared to its opposing force determines how an object moves through the air.

• • Weight:

• • • Weight is the amount of gravity multiplied by the mass of an object. 
    • Weight is also the downward force that an aircraft must overcome to fly. 
    • A kite has less mass and therefore less weight to overcome than a jumbo jet, but they both need the same thing in order to fly - lift.

• • Lift:

• • • Lift is the push that lets something move up. 
    • It is the force that is the opposite of weight. 
    • Everything that flies must have lift. 
    • For an aircraft to move upward, it must have more lift than weight. 
    • Lift for an airplane comes from its wings.

• • Drag:

• • • Drag is a force that pulls back on something trying to move. 
    • Drag provides resistance, making it hard to move. 
    • For example, it is more difficult to walk or run through water than through air. Water causes more drag than air.
    • The shape of an object also affects the amount of drag. 
      • Round surfaces usually have less drag than flat ones. 
      • Narrow surfaces usually have less drag than wide ones. 
      • The more air that hits a surface, the more the drag the air produces.

• • Thrust:

• • • Thrust is the force that is the opposite of drag. 
    • It is the push that moves something forward. 
    • For an aircraft to keep moving forward, it must have more thrust than drag. 
    • A small aeroplane might get its thrust from a propeller. 
    • A larger aeroplane might get its thrust from jet engines.