×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

US Standard Atmosphere Equation

US Standard Atmosphere Equation

US Standard Atmosphere Equation

(OP)
I am looking for an equation (using the US standard atmosphere) that will allow me to calculate pressure at any altitude in the troposphere (< 11km) when I know the temperature and pressure at another altitude. Standard temperature lapse rate (-6.5K/km) can be assumed or different value to be input.

RE: US Standard Atmosphere Equation

Hi bstjs.
I know the expression that gives you the relation between pressure at an altitude "z" for ISA (International standard atmosphere). I suppose that it be the same as US standard atmosphere. Here it goes:

Pz=Po*[(Tz/To)^(-g/R*k)]

Being:
Pz: pressure at a determined height (m)
Po: pressure at sea level (101325 N/m^2)
Tz: temperature at "z" height. In troposphere: Tz=To+k*z
To: temperature at sea level (288 K is used)
g: gravity (9.8 m/s^2)
R: gas constant (In air medium, take 287 m^2/(s^2)K
k: constant value ; take -6.5*(10^(-3)) K/m

I hope it be useful.



RE: US Standard Atmosphere Equation

(OP)
In my case,I don't want to assume stamdard temperature and pressure at sea level (since this is usually not the case).  I wish to use the information I have to improve my estimate of pressure at any other height (including sea level).  

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources