A useful Primer for aero Beginners

[j-c-c]

I suspect this video has been shared here before but I haven't seen it. I would think it covers a lot of useful ground regarding aero for anyone starting out,
I don't know enough to authoritatively critique it.

https://www.msn.com/en-us/news/opini...5417733b&ei=27

[freebeard]

Nor I, but that hasn't stopped me before.

I watched the first three minutes, and the last two before 'exit through the gift shop'. That's a weird website (MSN), no way to 1.5x the speed. Thumb down.

Anyways, they use pressure stress and shear stress where most would reference form drag and skin drag, which they do admit.

It does seem accurate, but they lead up to induce, wave and interference drag (not stress) and pitch their paid content.

Was there anything actionable in the middle?

[aerohead]

Originally Posted by j-c-c

I suspect this video has been shared here before but I haven't seen it. I would think it covers a lot of useful ground regarding aero for anyone starting out,
I don't know enough to authoritatively critique it.

https://www.msn.com/en-us/news/opini...5417733b&ei=27

1) @ 6:00, it would be better to have said that 'a turbulent boundary-layer', rather than 'turbulence' delays separation ( turbulence is a consequence of flow separation ).
2) @ 8:28, the 'visual' is incorrect, as in real flow, one would observe the Prandtl surface of discontinuity forming ahead of the body, and the most local streamline filaments would be 'far-away' from the structure, with the 'actual' wake region significantly enlarged in comparison to what is depicted.
3) @ 9:22, it would have been a great service to the viewer to have mentioned that, where the friction-drag line, and pressure drag line intersect each other constitutes the 'drag bucket', and that the fineness-ratio found at that point represents the 'MOST' streamlined, and lowest-drag teardrops.
The ratios will vary between 2-dimensional flow bodies and 3-dimensional flow bodies ( this is where the aerodynamic streamlining templates originate from, found in Sighard Hoerner's 'AERODYNAMIC DRAG' for 3-D bodies, and ' Aero-Hydrodynamics of Sailing', by C. Marchaj for 2-D bodies ).
4) @ 12:50, this very-low Reynolds number phenomena is called 'Hele-Shaw' flow.

[j-c-c]

Originally Posted by freebeard

Was there anything actionable in the middle?

Appears there is. I will review further tonight.