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World Airports Voronoi

Online visualization by Jason Davies presents the world organized as territories in relation to the distance between airports:

Each region is closer to a particular airport than any other. This partitioning of the sphere is called a spherical Voronoi diagram, and was calculated by d3.geo.voronoi, which is currently underdevelopment.

More Here

The Physics of the ‘Stall’

The proposition that more the angle of attack, more the lift does not hold at all angles.

At about 14 degrees, something weird happens and the aircraft instead of soaring the skies starts to plummet to the ground.

When this happens it is known as a stall.

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What causes Lift ?

The main thing to know is that a difference in pressure across the wing–low pressure over the top and higher pressure below–creates the net upward force we call lift.

Upon reaching a certain velocity, the aircraft’s lift is more than its weight and as a result, the aircraft takes off .


The Concept of a Boundary Layer (BL)

There is a high chance that you might have heard this word even in a casual conversation about wings and that’s because its an important concept in the context of aerodynamics and associated fields.

To understand the physics of a stall, lets consider the interaction of a moving air on a flat plate.


The nature of airflow over a wing/plate is the result of stickiness or viscosity of air. 

The first layer sticks to the wing/plate not moving at all.

The second layer in frictional contact with the first moves slowly over it.

And the third layer moves somewhat faster than the second

Thus layer by later the flow builds up to the free stream velocity or airspeed. These layers of flow are known as boundary layers.



What happens to the BL during a stall?

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During a stall, these successive tiers of air that form the boundary layer lose their gripping on the surface and break away into turbulence.

( what i mean by turbulence is the chaotic wiggling of the test leads attached to the wing in the animation )


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It takes a pressure difference between the top and bottom parts of the wing in order to produce lift. But when the flow of air becomes turbulent ( i.e during a stall ), this pressure difference is no longer established.

As a result of which, the lift drastically decreases and the aircraft starts dropping to the ground.


How to get out of a stall ?

Stalls can cause problems only when the pilot is not aware that the aircraft is stalling. ( Unlikely but has caused accidents in yester times )

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As the airplane loses altitude, its nose dips down and airspeed picks up quickly. This restores the lift and the pilot would be able to regain control and bring the aero-plane into level flight.


How are stalls detected ?

On light aircraft there is a reed (much like used on a musical wind instrument) mounted on one wing root, which is angled such that at the Angle of Attack which would cause a stall, the reed “plays” which can be heard in the cockpit.

Here is a view of where this system is mounted on a Cessna


On some aircrafts, it is a similar principal, however instead of a reed, it uses a fin which at critical AoA pushes a micro-switch which activates a buzzer/horn inside the cockpit.

Here is the assembly on a Beech 18


Large commercial aircraft typically rely on either Angle of Attack (AoA) Vanes or Differential Pitot Tubes  to supply input to flight computers for the purpose of calculating AoA.

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Review:

A lot of important stuff regarding aerodynamics in this post. Here’s a summary of the post:

Boundary Layer concept  — >  Why do aircrafts stall ? — >  How to get out of one  — > How are stalls detected ?


That’s all folks!

Hope you enjoyed today’s post and learnt something new.

Have a good one !

what secret makes the clouds blush?

sick of being in an elevator stuck between floors
we want to carve the world at its joints
want to articulate the je ne sais pas
the words of liminality

babies aren’t born knowing the difference
between themselves and the world
between the world and everything else

but once we find one boundary
we want to find more, we thirst for edges
we want to know what is on the other side of
the endlessly tapering sky

what is past the past?
what is beyond the beyond?

E naquela madrugada ela voltou a ser a garotinha de 10 anos que se esconde chorando embaixo das cobertas com o intuito de se proteger dos monstros imaginários, mas dessas vez ela não conseguiu se proteger dos monstros, pois o único mostro existente naquele quarto era ela mesma, com suas inseguranças e pensamentos grotescos.
—  Samira Melo
One of the hardest parts of establishing and maintaining boundaries is our fear of appearing rude or selfish. Your quest for boundaries hinges on your willingness to take care of yourself so that you can be there for others. This does not mean that you are dismissive of others or their feelings.
— 

wikiHow to Establish Boundaries

A boundary is a space between you and another person. As the gatekeeper, you can decide how close another person gets to you physically and emotionally.

Healthy boundaries are a way to protect yourself, giving yourself freedom to conduct your life in a way that helps you flourish.

1. Healthy emotional boundaries mean that you are able to voice your desires and preferences. Your emotional boundaries separate your emotions from those of another. They protect your self-esteem. Examples include:

  • Your own health and well-being are important, and you will not be forced to neglect your own needs.
  • You have a right to be treated with respect.
  • You will not be manipulated or forced to do things you don’t want to do, even if the other person is attempting to make you feel guilty.
  • You won’t allow others to yell at you, make you feel bad about who you are or what you are doing, or call you names.
  • You don’t blame others for things that are your responsibility, and you don’t allow others to blame you for things that are not your responsibility.
  • You keep your emotions separate from other people’s emotions, although you empathize with the people you care about.
  • You convey your own needs assertively, and work towards cooperation if possible. This helps maintain mutual respect.

2. Recognize physical boundaries for your physical self.

  • When someone intrudes on our physical space, we feel it internally. It feels awkward and unnatural.
  • When you are in a relationship, make sure you are comfortable with how you express yourself physically with the other person. Have a conversation about what will make you feel safe and loved.
  • Northern Europeans and North Americans observe the largest personal space distance.
  • People in Middle Eastern countries, South America, and southern Europe have the smallest personal space distance, and touching is common.
  • Eastern cultures consider touching or patting on the back as taboo and offensive.

Physical boundaries are often described as personal space. Personal space includes physical possessions such as your home, your bedroom, your belongings, your car, etc. It is well within your rights to establish boundaries with others about respect for your privacy and your possessions.

Learn more here.

Respect My Brownies, Boy
  • Luke:[age 11] "Dad, Beth won't let me hug her."
  • Beth:[age 8] "I don't want you to hug me!"
  • Me:"Luke, don't hug her."
  • Luke:"But I want to hug her!"
  • Me:"She said no. End of story. You don't get to be in someone's physical space just because you want to. She has to want it, too. Respect her boundaries. This is /always/ true for everybody you meet."
  • Beth:"Yeah! Respect my brownies! I mean, boundaries!"
  • Me:"Well, I suppose you need to respect her brownies, too."
  • Luke:"Now I want her brownies."
  • Me:"You don't get her brownies unless she says you can."
  • Beth:"That's right. They're mine. You better respect my brownies, boy!"