Understanding Aerodynamic Drag

Drag and lift are the forces which act on a body moving through a fluid, or on a stationary object in a flowing fluid. We call these aerodynamic forces (if the fluid is a gas) or hydrodynamic forces (if the fluid is a liquid).

This video is all about the drag force. There are two main causes of drag - first we have the pressure distribution around the object, which is particularly significant if flow separation occurs. And then we have the shear stresses acting on the object, which are most significant for streamlined bodies.

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[tmmyvrctt]

This video is more useful than whole semester fluid course

[rashedabuamoud]

Just finished my fluid mechanics course, this video sums everything up so elegantly. Love your videos!!!

[mallikarjunv]

0:00 - 0:30. Introduction to Drag (What is drag ?)
0:50 - 1:05. Why is drag an unwanted force ?
1:30 - 2: 18 How is drag generated ? and formula for calculation of drag
2:19 - 2:31 Components of Drag force (Pressure drag and Friction drag )
2:32 - 3:19 Pressure drag in detail
3:20 - 4:47 Flow separation in detail
4:48 - 5:00 Why do golf balls have dimples?
( Dimples increase turbulence and hence reduce flow separation. Reduced flow separation means less "pressure drag" and so the ball travels large distance).
5:01 - 7:15 Turbulence and its effects on Pressure drag and friction drag
7:17 : 8:05 Ridges on shark skin as bio inspired solution to reduce friction drag.
8:07 - 9:31 Effect of geometry and the orientation on Total drag.
9:32 : 9 :51 Quantification of drag force through integral approach.
9:52 Simplified formula for drag force.
9:53 - 10:11 The drag coefficient and how it's calculated.
10:22 - 10:36 The reference area (Emphasis on the selection of Area.)
10:37-12 :25 Re Vs Cd and arriving at stokes law.
12:26 -13:26 Arriving at terminal velocity of a sphere.
13:29-13:53 Constructing a Viscometer (In breif).
13:57-14:22 Components of drag forces of particular interest in aviation

[muhammadabdullah]

This video is essentially a summary of chap 9 in the fluid mechanics book by Munson. I love how this channel explains these important topics with such simplicity. Keep up the good work.

[titorotod]

I got so excited to see this on the feed, I was long waiting for a video about this. I started working on computational fluid dynamics half a year ago and it took me a lot of time to learn the theory behind it. You make everything look so easy to understand, you truly are a gifted teacher. Cheers!

[TheEfficientEngineer]

I hope you enjoyed this look at aerodynamic drag! I'll be covering lift in the next video.
✈️

[shauryagupta]

Atlast A video on drag, the way you explain concepts is really Please keep uploading more and also more frequently

[berkdogu]

The Efficient Engineer has actually encouraged us to prepare such videos because all videos in this channel are very descriptive and informative.

[aliptera]

The most intuitive and real physical explanation of all aerodynamic forces I can think of - is modification of static atmospheric pressure around an object due to air movement. Atmospheric pressure is defined by random bombardment of air molecules as per the kinetic theory of gases; this randomness is changed by the macroscopic air movement. As a result the pressure is modified around the object creating forces that we're labelling as drag and lift.

[stefanguiton]

another gem of a video, keep up the great work you do!

[Megadanne]

This is not the first time you've managed to time your content with the same subjects I'm studying at the time, great video!

[NikitaKaminskyy]

As I said it many times, I wish someone explained me these concepts as well as you do back in the days!

[LJv]

Clear, concise, straight to the point, great illustrations, please keep doing those ! Hi from France !

[alexanderunguez]

I really enjoyed that you pointed out that pressure drag becomes more significant for blunt objects and friction drag becomes more significant for thin structures(and pipes I should add). This is something that isn't specifically mentioned in a lot of literature, but is an important intuition.

[magarinoskevin]

Somehow you manage to cover the topics I'm coursing right now at Uni
Truly a gem of a channel

[naveenkondeti]

Wahh...!
Solved many of my doubts regarding fluid mechanics in a single video. The best of best 👏👍.
Engineers of our generation are blessed to have such sources.
Thanks for providing such content and keep doing it.

[mazenelgabalawy]

These types of videos and people like you sir are the reason I still have hope I can truly understand what university professors poorly teach.

[mosayed]

I was thinking about you from a while, I said to myself why didnt he uploaded something till the moment and here you are❤

[mohammedfawaaz]

the hell do you explain so much really explain clearly and hats off proud to the the best

[kariossyr]

Really great! It's so rare to find such simple analysis while being thoroughly! Keep it up. I really enjoyed your comprehensive language.