Skip to content

Conversation

giantplane
Copy link

Hi Prof. Barba,

I was just able to work out a draft of my project, which is to simulate the wake of a flat plate after suddenly changing a small angle of attack. I apologize for any typos as I will continue reviewing it. A visual validation of the rolling up starting vortex and an animation is produced at the result section. I'm wondering if you could take a look and give me some feedback.

Sincerely,
Jingjing

@labarba
Copy link
Member

labarba commented May 14, 2015

Passive voice -- you seem to have caught the zombie virus of technical writing.
Shaket it off!

"an unsteady panel method is implemented…" by zombies
"The numerical experiment is conducted…" by zombies
"A series of discrete vortex, or a vortex sheet, are employed…" by zombies

Check out my tweet:
https://twitter.com/LorenaABarba/status/592146187089743872

Try, as an exercise, to go over your text and find all the instances of passive voice, and ask yourself if you could say the same thing without that construct.

For example, if I were to rewrite your first paragraph, I might go for something like this:

"Capturing wake effects in an unsteady motion in the framework of potential flow requires that we use unsteady panel methods. We can set up a numerical experiment using a flat plate that starts moving in an imposed trajectory. To describe an infinitely thin lifting surface, panel methods use a series of discrete vortices, or a vortex sheet. We can also add sources to include the effect of thickness, but that will be outside the scope of this project."

Notice how the passage above uses the left-to-right, natural order of subject/verb/object. Notice the verbs: capturing, requires, use, set up, moving, add, include, will be.

You should try to write so that it is always clear who does what.

In cell [1], you input a your helper functions, but your notebook doesn't tell us what's in there. It would be nice if you told your reader what you provide in that Python file. Reading the source, I count nine functions ... only two of them have docstrings, though. It's good practice to always include docstrings: they are better than comments, because the user can type help and get that documentation without reading the source code!

In your results, there are two images that are not rendered in the nbviewer. In the raw file, I see that you are loading the images in markdown like this:

</center>![image](files/figures/gamma_t.png)</center>

Try using HTML tags instead, like this:

<img src="./figures/gamma_t.png" width= 500>

(changing the width to whatever you like, in pixels)

"It shows good agreement with the literature …" —> What literature? Can you give the specific source that you compared with?

"The jump from constant circulation to a parabolic type of curve in the literature figure is the point that the flat plat experiences the sudden change in angle of attack."—> What?

Finally, I would like to see your submission show a fully executed notebook, not the results as an embedded image from what looks like a screenshot. You included in the notebook a few code cells, but you don't explain what they are doing. I see your call to animate_wake() but I don't see where you call iteration(), so I'm a little confused by the presentation of the executable part of your project.

Typos, grammar, etc.:

"The resulted flow field …"—> resulting
"The wake will rolls up …"—> roll up
"increase of angle of attack …"—> of the angle
"resulted from the presence…"—> resulting
"requires that velocity vector…"—> the velocity vector
"angal of attack"—> angle
"flow tangency condition"—> flow-tangency condition (hyphen on the compound adjective)
"enforcing Kutta condition"—> the Kutta condition
"instead of the specific value of themselves."—> uh?
"If taking half of the summation of above equations:"—> Adding the above equations and dividing by 2
"It is shown that the mean …"—> Which shows that the mean
"produce desired v(x) behavior"—> the desired v(x) behavior
"a series of vortex "—> vortices
"Discontinuity exist in u velocity"—> A discontinuity exists in the u velocity
" applying a Stoke's theorem"—> applying Stokes' theorem
"Plugging the eqution"—> equation
"back to the conclusion of previous section"—> back in the final expression of the previous section
"Velocity field induced"—> The velocity field
"a series of expansion"—> a series expansion
"It is shown"—> It can be shown
"all terms in the above formulation vanishes"—> vanish
"thus Kutta condition is retained"—>thus, the Kutta condition is satisfied.
"This study adopts this placement that"—>Here we adopt this placement of
"moving with fluid"—> moving with the fluid
"mathematcally"—> mathematically
"Free vortex is generated"—> A free vortex
"influence on all other vortex"—> vortices
"the shedded vortex"—>the shed vortex
"velocity of free vortex"—> the free vortex
"moved the RHS"—> moved to the RHS
"Velocity at each control point "—> The velocity
"consist of three parts"—> consists
"Induced velocity by "—> The induced velocity
"A linear system need to be solved"—> needs

@giantplane
Copy link
Author

Prof. Barba,

Thank you very much for the comments. All those people that promised me to proof-read my writing, has not provide me so much insights about my writing style or choice of words. I'll try to rewrite my stuff in a tone of natural order. It really sounds different.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

Projects

None yet

Development

Successfully merging this pull request may close these issues.

2 participants