Brand new at this please help !

[fastman614]

oh

[Stan Back]

I could be wrong (and, as many of you know, am often), but this whole ordeal -- yes, ordeal -- seemed to be perpetrated by someone who had no idea of ever constructing anything, but instead proposed many theoretical ideas that appealed to many of our more verbose responders who jumped in with theoretical-laden answers.  And was smart enuf to keep them going -- for what purpose I don't know.  But it sure fills up the forum, and might be interesting to some, but useful?  I don't know.

[fastman614]

Stan,
Is participation in these posts mandatory?.... If so, I ask, where were the other hundreds of people?... but, if not, and it was or is perceived as a waste of time, why on earth did the "armchair experts" continue to weigh in?

Taking taper41 at his word, he is a junior engineering (perhaps technology) student with an interest in this stuff.... well, I am pretty sure that he got a lot of information about real world applications vs theory here..... and will always recognize the "lesson" he probably learned....

For me, there were several rather interesting ideas etc that were put forward here.... i copied them all and filed them in my lakester areodynamics file .... and I deliberately left the lower case "i" a bit back to see if I could make someone's "high point of the day" by them pointing it out to me that my post is not typographically correct!

I do not disagree that the same questions pretty much got recycled .... but, having dealt with techie types for decades now, this is not a surprise to me.... it is what they do if they don't think they understand.... and in the real world, THAT is a lot better of a situation than having them go away saying that they DO understand, when they DON"T!.... I have seen some pretty hellatious errors made when that DOES happen!

Sooooo...... till another topic then....

[dr j]

I could be wrong (and, as many of you know, am often), but this whole ordeal -- yes, ordeal -- seemed to be perpetrated by someone who had no idea of ever constructing anything, but instead proposed many theoretical ideas that appealed to many of our more verbose responders who jumped in with theoretical-laden answers.  And was smart enuf to keep them going -- for what purpose I don't know.  But it sure fills up the forum, and might be interesting to some, but useful?  I don't know.

Stan,
Over the last several yrs I have often appreciated the intellect that must be behind your clever though oft times nasty wit.  But I certainly do not appreciate the multiple posts you have made in this thread about how much of an ordeal it was for you.  Since it was an ordeal, use your intellect and stop reading further posts on this thread.  Nothing constructive or admired in your comments here.  As for the lack of Taper's build plans please note that this thread was very appropriately placed in the Tech Section and Aerodynamics rather than a Build Section.  There have been multiple other purely theoretical discussions in this Aero zone.  Some have even been verbose and not practical but often with some kernals of interesting things to file away as Fastman mentioned and I totally agree. 
Taper,
Good luck applying some of this thread info to your school endeavors and I hope someday you apply some of it to an actual build too.

[rgn]

the question i had was if you decrease the aerodynamic drag by 25% or add power by 25% would the result differ or be the same, if it was on the same vehicle

Here is the problem I see with your question Taper.  "Same vehicle"  While you can vary power up or down with the vehicle remaining the same, you can not decrease or increase it's aerodynamic drag with the expectation that nothing has changed.  If aerodynamic drag was reduced 25%, it would no longer be considered the same vehicle surely?

I'm not an aerospace engineer, I'm an aircraft maintenance engineer, and a FAA master parachute rigger.  I have studied philosophy, psychology, and sports science at university.  

[taper41]

lincoln institue in not in upstate, i am home from school for the summer.  I'm not going to argue over something so silly as to whether someone believes i attend school or not.

I entered this forum to ask questions yes, and Fastman, Dr. J , thank you for supporting my questioning, however to the others, I have not forced anyone to respond to what i have written, which is why i don't understand why it is so important for you to tell me how ignorant my questions are to you.  Whether i build my own vehicle, or it is a way to help me understand what i am studying better how I apply it doesn't concern you, even I know asking a question with a question is very confrontational.

I dont understand the point of putting others down simply because you don't understand their motive, I have never been that way.

If this is not interesting to you then simply move on to something that does.
Like i said I will keep my nose out of the forum.

[tortoise]

if  you decrease the aerodynamic drag by 25% or add power by 25% would the result differ or be the same, if it was on the same vehicle?

Set unit values arbitrarily so power/drag ratio is 1.
Decrease drag by 25%, power/drag is 1/.75=1.33.
Increase power by 25%, power/drag is 1.25/1=1.25
Ergo, result differs, decreasing drag 25% gives superior result.

[Peter Jack]

Taper, the difference is that most of the guys on this forum are practical engineers whether they are engineers by education or not. When you get out in the real world, if you are a guy who actually builds stuff you'll find that many of the engineers you work with have very little feel for the actual work required or for the methods that must be used to manufacture a part the engineer designs. If your direction is engineering I'd recommend that you ensure that you get much more than the minimal experience provided by your courses or you'll face this same type of reaction throughout your career. An engineer who knows and expounds the theory but doesn't at least have a real understanding for the practical is usually just a pain for those carrying out the actual work.

Pete

[taper41]

if  you decrease the aerodynamic drag by 25% or add power by 25% would the result differ or be the same, if it was on the same vehicle?

Set unit values arbitrarily so power/drag ratio is 1.
Decrease drag by 25%, power/drag is 1/.75=1.33.
Increase power by 25%, power/drag is 1.25/1=1.25
Ergo, result differs, decreasing drag 25% gives superior result.

See now before I get badgered for questioning an answer, a few pages back, some one had already answered this question, stating that both these factors are interchangeable or if changed by the same percent you would reach the same result. So i apologize ahead of time for not understanding the contradiction.

I would Like to understand hahaha

[tortoise]

So i apologize ahead of time for not understanding the contradiction.

I stand by my result. I am an authority on such matters, having studied algebra in the eighth grade.

[taper41]

Tortoise, im not saying your wrong I just dont understand how you came to that conclusio what made you choose that as a constant variable. I understand that power is cubed and drag is squared so I want to understNd the work your doing to get to your answer I would have thought if you change either by the same percentage that you would get the same result since they are differdnt units of measurements , larry do you want to jump in here

[tortoise]

Tortoise, im not saying your wrong I just dont understand how you came to that conclusio what made you choose that as a constant variable.

Engineers also need good communication skills, taper.

Neglecting rolling resistance for simplicity, and assuming appropriate gear ratios, if the unmodified car went 100 mph, the lowered drag modification would result in a speed of 110.1, the increased power modification would give about 107.7.

If you really understand the things you say you understand, you should be able to do the math. Think!

[Seldom Seen Slim]

Tortoise, I remember that issue - about engineers being able to be understood - very well.  It provided me with untold amounts of pizza and beer when I was in college at Michigan Technological University. 

The most common course of study was, for sure, this or that kind of engineering.  And the often-repeated phrase uttered by them was "Six munce ago I cudn't hardly spell enginnear - and now I are one".  As a liberal arts major (me, really) I typed essays and many other reports for them - using English that could be understood by the instructors.  I was paid in the coin of the realm - pizza and beer.  They got better marks on those papers when I edited and typed them. Q.E.D.

[tortoise]

If I recall correctly, you stopped playing comma cop after Willie threatened violence for your criticism of Sheri's language.

[Seldom Seen Slim]

Well, sort of.  That is -- I still find most of the punctuation and other errors but don't mention them nearly as much as I used to do.  I've finally realised that the vast majority of folks don't like to be reminded of their failings.