Boundary Layers

I walked outside yesterday and felt the wind blowing around me and I thought to myself "There's a boundary layer around me!" It was so exciting.

You see, a boundary layer is that layer of air right up close to some object that has fluid flowing over it. Suppose you were like me and you went and stood outside with the wind rushing past you. Because of friction, the air exactly next to your skin is not moving, it has a velocity of zero. And then as you get farther from your skin, the friction is less and the air begins to move slowly and so on, increasing in speed until it has reached the same speed as the rest of the flowing air around you. The section of air from right up exactly near skin to the point where is has increased in speed to the rest of the air is called the boundary layer because it is a layer all around you of air changing velocities. Now the reason you don't feel this is because it is so extremely small. But it becomes important when working with things like submarines or airplanes because the boundary layer is larger and affects the performance of the object more.
But they can be fun to learn about.

Dimensional Analysis and the Buckingham pi Theorem!!!

The Buckingham pie Theorem is used to help Dimensional Analysis of pies by using coefficients and coefficient connoisseurs to analyze the dimensions of the circularity of the pie and the parameters thereof including and not limited to the radius, the circumference, and the angular velocity.

The following definition is premeditatively and with the deliberate design to confuse categorically and without exception wrong and misleading. Pay no attention to it.




Dear me, what fun it is to use a Thesaurus. And truly the Buckingham pi Theorem has nothing whatever to do with pies or the analysis thereof. It is really instead a method of finding things out about fluid flows without having to use dimensions which is especially nice for comparing things particularly when you have some model of some prototype. For example, suppose I want to build a gigantic jet engine and I know that the power it uses is dependent on some certain variables (like how fast the engine is pushing air out). Well, to actually build it and then run and test it and then modify it, etc... would take a long time and a lot of money. So I build a little tiny model instead. And so I have to change a number of things to get results that will also be true for the big gigantic engine. And I can compare everything by using dimensionless units in the very neat method outlined by the Buckingham pi Theorem.

mouses and micetraps

Heh heh, so yeah, I never did get around to posting more over the summer.
It was a great summer though.
I discovered Isaac Asimov's robot series with Elijah Baley.
And found that the Stewart's on my way home had tasty chocolate milk.
And we had many girls over for dinner every Monday night.
And lots of other little things went on.

And just this week the Semester started again.

And, horror of horrors! A mouse ran across my floor Sunday night. I was not happy. Mice should have no business running across my floor.
So my roommate's sister got us some mousetraps (not sticky ones...my roommate and I both agreed that we detested those). And together we set one on a paper plate in our kitchen Tuesday night. It sprung almost immediately after, but it turned out it just wasn't set firmly. So we reset it and then avoided it like the plague. Then, yesterday, I came home after TAing a class and saw around the corner that the trap had flipped over. So I peeked a little closer and sure enough: we had our mouse!
My roommate and I were both disgusted and contemplated calling someone up and bribing them with dinner if they took care of our mouse. But then we decided that we were independent young women so we could jolly well take care of our own mouse. And we did...using a shovel and a garbage bag.
We were so happy after that that we ended up calling people up for dinner anyway just to celebrate.

Happy Day

Happy 40th year anniversary of the moon landing!!!

Being July

And I skipped posting during the entirety of June.

Howsoever, I can now report that I have successfully finished my junior year, have found a summer job, conquered my fear of buses, and read my way nearly half through a great book.

I believe I have mentioned the end of the semester before. So that needs no explaining.

The weeks following were spent recovering and replenishing sleep and searching for jobs. But about one or two weeks in to June I started working as a happy hourly employee at a local retail store. I have the most exciting job. I get to run around with a funny little scanner thing and scan the price labels of all the things we are out of or nearly out of in the store. And then I get to run to the back room and push out large tubs of all the things needed to replenish. I have now developed a hearty appreciation for zoning (the process of keeping everything in the proper places) and I would like to take this opportunity to ask you all to please try to put things back as close as possible to where it belongs and please don't leave articles in completely random places where they have no place being!

This job is also one of the reasons I haven't posted in a while. Every morning of work, I get up at a little after six and leave before seven to catch the bus. Then I get home about three-thirty exhausted. So I haven't wanted to do anything. But I think I am finally getting used to it.

Anyway, I have had to take a bus out to work and back. This was a major step for me, because, as everyone knows, buses are scary confusing things with schedules that are hard to figure out and bus stops that are hidden in random locations. Actually, I found that this is not quite true. Buses do sometimes have complicated schedules, but they are relatively simple to ride on once you figure out how. And I guess I've become a regular now or something. I have people smiling at me and talking to me as we wait. And the bus driver on the way back recognizes me, I'm pretty sure.

As far as the great book I am reading, I have finished chapter seven out of fourteen of The Reason for God by Dr. Timothy Keller. My dad suggested I read it and blog about it. It has been very interesting. I was able to read so much by reading it while waiting at the bus stop for the bus ride home. Actually, I occasionally read it on the bus too and because of it had a conversation with an older man named Jake who was hard to understand but who enjoyed talking. I couldn't grasp enough of what he was saying to understand his handle of the gospel, but he did claim to be a Christian.
So, based on the previous paragraph, it is obvious I haven't been blogging through that book, so maybe I'd better start.

Spock Rocks!!!

And I am most certainly squelching any and all comments about my nickname and Captain Kirk with more vigor than before from now on, thank you very much. I don't care if he does have blue eyes and is attractive and a bit wild. I don't like him, and that is that.

Fortunately I am upheld in my opinions by my roommate who shares them wholeheartedly. Hum, does it have something to do with the fact that we are both engineers? I mean, our two humanities friends liked Kirk way better than Spock.

Nonetheless, I have just seen an amazing movie, and am now wishing I had watched Star Trek more often when I was younger. Such zoomings! and blastings! ...and why was the elder Spock's spaceship designed that way??? (that was my roommate's question: wouldn't it create a gyroscopic motion that would cause the ship to curve when flying?)

And my little toe may have a small blister again. We went dressed up on the spur of the moment so I put my new sandals on. It was because we were all so fat and full and lazy from an amazing tea party we held in honor of my roommate's birthday...speaking of which: Happy Birthday Roommate M! May you live long and prosper!

Anyway, nearly all the guest had left save two good friends, one of whom is staying several nights. And we were all fat and full and lazy and dressed up in dresses and skirts and scarfs and hats. So we decided to see a movie. And I was the only one who hadn't seen Star Trek yet...but they all didn't mind seeing it again. In fact they claimed it improved on second showing. I don't know about this. I've only seen it once. And that was enough. Man, I really wish I had studied coordinate systems and basis transformations better...maybe I'd have gotten a better grade in my Spaceflight course this past semester.

And on the way home, we argued over whom we would rather marry, Kirk or Spock, with the nice divide I mentioned earlier.

And time paradoxes are always interesting and puzzling to my brain. Hurrah!
Also, there was really only one objectionable part which was probably considered okay because a lot of girls wear bikinis in public, but I still call a bra underwear. And therefore not to observed. I promptly closed my eyes for the minute or two of that. Pretty sure that was all though...which is always nice.

And now: do you think there is one reality or multiple? 'Cause if you've got multiple, you can end up with one person in two places at the same time, but otherwise one ought to disappear, at least I think so. No wait! It's like Schrodinger's Cat! Bother...now I'll stay awake thinking about this.

Semester is Done

And now I can think again. We made it through five finals and two projects and came out exhausted but done presumably only by God's grace. 'Cause let me tell you, Elements of Mechanical Design was a most boring class in which every week you look and say "Oh! more homework due" even after having an exam. And the Spaceflight final exam was nothing like expected and my calculations were seriously off because why on earth would a spacecraft carry four times as much fuel as it actually needs unless my numbers were wrong? And the Mechanical Systems Lab had incredibly long and intensive lab reports that did not fit the two-credit class expectation of work. And I discovered that three hours of sleep and fasting all day makes me look like a ghost.

But the Modeling and Control of Dynamic Systems class was fun. The course work used many Laplace transforms and partial fractions, which I just love. And the Aero Structures Lab had very little work but five fun experiments.

And I met and bonded and formed friendships with people in my classes. And my roommate introduced me to Zumba which is an amazing way to exercise since it incorporates dancing into the exercising. And my family and my friends supported me when I thought I was going to lose it. They told me to get some sleep. And God told me I need to trust Him more and give Him my love.

(By the way, it is amazing what sleep can do for you! How happy you feel and how much things look better when you've slept full nights of sleep several nights in a row! The change is dramatic and you must all try it sometime.)

So all in all...
I think it must have been a good semester.