Category: aerodynamics

“Blow your brains out” moments

cosmicnoon_r6mdvb

Sometimes, as I am staring into the deep soul of my monitor, my mind momentarily drifts to thinking about the glimmering pixels which are being updated right before my eyes. Such an extraordinary piece of technology, now just tossed into commonness.

Now, it would be quite comical for a person to become fascinated by every single thing that they see around them but, this makes me wonder: what technology traits make people ‘blow their brains out’. And does this have any dependence on the time they were born into?

–> S curve growth of technology:

Jason in this blog post, talks about a “natural S curve” for analyzing progress and quotes:

Every technology, defined narrowly enough, goes through an S-curve: it starts out small, picks up steam, hits a hockey-stick inflection point, grows exponentially—and then starts to near saturation, slows down, levels off, plateaus.

And regarding how breakthroughs open the flood gates to new invention, he says:

… But when some breakthrough insight creates an entirely new field, it opens an entire new orchard of low-hanging fruit to pick.

I think this is an interesting way to think about progress and would be great to quantify this more rigorously.

–> How YOU can Invent the Future in 2022 — like the Wright Brothers did in 1903.

On supersonic passenger jets

cosmicnoon_r6mdvb

I was recently watching this vox video and BBC documentary on the Concorde and supersonic travel. The fluid dynamics of air at mach speeds greater than 1 is a fascinating subject on its own accord.

 

  • Stagnation enthalpy

    • Stagnation enthalpy is defined as the ‘Enthalpy of a fluid when it is brought to rest from velocity v isentropically’. Stagnation properties such as Stagnation enthalphy, pressure, temperature are often used to quantify the fast moving air around a flight moving at supersonic speeds.
      • “For very low Mach numbers, the density of the air is a constant. But as the Mach number increases into the supersonic regime, some of the energy associated with the motion of the object compresses the gas and changes the density from its static value….. As the Mach number increases into the low hypersonic regime, some of the energy of the flow excites the vibrational modes of the diatomic molecules.”

 

  • How to photograph shock waves ?

    • Imaging shock waves in a laboratory can be achieved through specialized tools, but NASA regularly posts images of shock waves around jets flying way up in the sky. How does one begin to visualize shock waves from an around an aircraft at several thousands of feet in the air. This post runs through a few techniques that are commonly employed

 

  • Vapor cones and condensation
    • Slowing down to Transonic speeds, a visible cloud of condensed water form around a fast moving aircraft or object known as a ‘vapor cone’.