Solved

Apache Helicopter

Posted on 2003-10-25
3
435 Views
Last Modified: 2011-09-20
I don't know if this is the right Topic, but I think it is, it has something to do with science.

I was curious if anyone knows how fast the propellers of an Apache helicopter go, like RPM's a minute or whatever, and how long are they, I guess if you could tell me the total (wingspan?) that would be okay.

I asked my parents this and they said just write on your homework, "Really damn fast and pretty damn big.", so if you think the same thing I am going to tell you the samething I told them.

This is not a homework problem!  I am just curious, I had an idea.  If this is not good enough for you, then I will come up with an excuse.  I am coming up with a very hard Calculus problem that I am trying to stump my friend with.  How's that?

Mark
0
Comment
Question by:simpsons17371
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
3 Comments
 
LVL 5

Accepted Solution

by:
SethHoyt earned 150 total points
ID: 9621741
The rotor speed is 4.86 Hz according to http://www.vibrationdata.com/Newsletters/April2003_NL.pdf

This translates to 292 RPM, consistent with the 289 RPM used in this simulation of the Apache's rotor system:

http://www.lions.odu.edu/~dkunz/conf/2001ApacheRotorRSC.pdf


The rotor diameter is 14.63 m, according to http://www.zap16.com/mil%20fact/ah-64%20apache.htm


That gives a rotor tip speed of about 4.86 * (2 * 3.14 * 14.63) = 447 m/s = 1000 mph

-Seth
0
 
LVL 5

Expert Comment

by:SethHoyt
ID: 9621747
oops.. sorry, I multiplied diameter by 2 instead of radius.

The last bit should be:

That gives a rotor tip speed of about 4.86 * (3.14 * 14.63) = 223 m/s = 500 mph


-Seth
0
 
LVL 55

Expert Comment

by:andyalder
ID: 9622550
You have to add 273 MPH if it's going at full speed forwards, so the leading edge is going 773 MPH, just below the speed of sound at its operating height.
0

Featured Post

Free Tool: ZipGrep

ZipGrep is a utility that can list and search zip (.war, .ear, .jar, etc) archives for text patterns, without the need to extract the archive's contents.

One of a set of tools we're offering as a way to say thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Where is the math error. 13 74
Logarithms 2 86
C/R - what does it mean in postal address 2 103
hardness of water, iron in it, and effect on humans.. 6 93
Foreword (May 2015) This web page has appeared at Google.  It's definitely worth considering! https://www.google.com/about/careers/students/guide-to-technical-development.html How to Know You are Making a Difference at EE In August, 2013, one …
Have you ever thought of installing a power system that generates solar electricity to power your house? Some may say yes, while others may tell me no. But have you noticed that people around you are now considering installing such systems in their …
This is a video describing the growing solar energy use in Utah. This is a topic that greatly interests me and so I decided to produce a video about it.
Finds all prime numbers in a range requested and places them in a public primes() array. I've demostrated a template size of 30 (2 * 3 * 5) but larger templates can be built such 210  (2 * 3 * 5 * 7) or 2310  (2 * 3 * 5 * 7 * 11). The larger templa…

710 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question