naca-tn-99

Downloads11
File Size361.65 KB
Tags   Atmospheres     NACA     Technical Notes  
Download
FileAction
naca-tn-99 Notes on the Standard Atmosphere.pdfDownload 

National Advisory Committee for Aeronautics, Technical Notes - Notes on the Standard Atmosphere

naca-tn-99-notes-on-the-standard-atmosphere-1

This report contains the derivation of a series of relations
between temperature, pressure, density and altitude in a "stand—
ard atmosphere" which assumes a uniform decrease of temperature
with altitude; The equations are collected and given with proper
constants in both metric and English units for the temperature
gradient adopted.by the National Advisory Committee for Aeronau-
tics. A table of values of temperature pressure and density at
various altitudes in this standard atmosphere is included in the
report.

Certain interesting and significant relations exist between
pressure, density, temperature, and altitude in a "standard at—
mospheren which assumes a linear decrease of temperature with al-
titude. such an atmosphere is in extensive use in EurOpe and ha'
recently been adqpted by the National Advisory committee for aero
nautics for official use in the United states. The derivation of
the more important of the standard atmosphere relations and their
tabulation in form for ready reference seems to be a practical
method of indicating the way towards a utilization of the many
advantages of a standard atmosphere.

A discussion of standard Atmosphere may be found in National
Advisory Committee for Aeronautics Report NO. 147, by W} R. Gregg-
A few brief remarks will be made for the benefit of those who do
'do not have a copy of that report available for reference.

"standard Atmosphere," as the name implies, is an atmosphere
in which fixed values of pressure, temperature and density are
adopted, more or less arbitrarily, for each altitude; such an at~
mosphere is required in comparing the performance of aircraft and
aircraft power plants. The most satisfactory of all proposed.

while it is desirable that a standard atmosphere be a close
approximation to actual conditions, this requirement should not be
.stressed. The chief purpose of a standard atmosphere is to supply
a basis for comparison of performance and not to specify the tem-
perature and pressure obtaining at a given absolute altitude at
all times. It so happens that "Toussaint's Rule" expresses with
. considerable accuracy the average annual conditions for latitude
40° in the United states. This is not altogether accidental since
the temperature gradient is based on averages, but it is very
doubtful if the standard atmosphere ever expresses the true condi—
tions at a given instant. nevertheless, the "standard atmosphe::“
when properly understood and used is of great value in aeronautics.


Have A Comment On This Article? Post It Here.

Comments are moderated and will not be published until approved. Your email address will be kept confidential. Please review our Comment Policy before posting your comment.

*

Microsoft Excel Spreadsheets

FREE ANALYSIS SPREADSHEETS 3 Over the last 10 years we have developed hundreds of spreadsheet tools to help us with our structural analysis work. We have made these available through the Abbott Aerospace web site and the XL Viking project. We have now brought them into the technical library. They have been updated, improved and the collection has been expanded to cover more analysis methods than ever before.

The XL-Viking Add-In for Excel

XL-Viking 2 We created the XL-Viking Excel add-in to satisfy our own need to make Excel a better engineering tool. XL-Viking shows your Excel Formula in a way that makes sense and brings essential new functionality to Microsoft Excel by providing an additional user interface and easy to use functions.

The Indispensable Tool For Engineers, Mathematicians, Scientists, Accountants and Teaching Professionals!

download-xl-viking

Technical Papers & Reports

This is our collection of public domain references. All of the material we make available has been placed in the public domain by the authors/owners. If you believe this is not the case and any of the library material is not in the public domain please let us know. If you have any reference material that you would like to see included in the library we would love to hear from you.

Market Analysis and Market Information

Our newest addition to the library is an on-going series of articles on the aircraft and aerospace market. These are part quantitative and part qualitative and introduce a new aspect to the competencies within Abbott Aerospace.