Standard atmosphere Andonova Alena MA-283 Aims Speak

Standard atmosphere Andonova Alena MA-283

Aims Speak about Main characteristics of standard atmosphere Using standard atmosphere patterns in atmospheric sciences Calculating some values of features for ISA http: //earthsciencelessonplans 101. blogspot. ru

Main characteristics of standard atmosphere The real atmosphere never remains constant at any particular time or place, a hypothetical model must be employed as an approximation to what may be expected. This model is known as a standard atmosphere. http: //quest. arc. nasa. gov

International Standard Atmosphere, Mean Sea Level Conditions (1952) Pressure p 0 = 101 325 N/m 2 = 1013. 25 h. Pa Density ρ0 = 1. 225 kg/m 3 Temperature T 0 = 288. 15 K (15°C) Speed of sound a 0 = 340. 294 m/sec Acceleration of gravity g 0 = 9. 80665 m/sec 2

Pressure and Temperature variation in US Standard Atmosphere (1976) http: //atmos. caf. dlr. de

There are some features: ISA Atmospheric temperature Atmospheric pressure Air density Speed of sound Kinematic viscosity Thermal conductivity US SA Atmospheric temperature Absolute pressure Air density Acceleration of Gravity Dynamic viscosity For altitudes from -2000 to 30000 m For altitudes from -1000 to 80000 m

Calculating A vertical gradient of molecular temperature: Temperature is linear function of geopotential height: where μ 0 = 28. 9645 kg/kmol

Distribution of pressure was calculated by barometric formula for polytrophic and isothermal atmosphere: static equation compiles with and then: where

In homogeneous atmosphere area gravity acceleration decreases with altitude: where a = 6371. 21 km and gradient are different in homogeneous atmosphere.

Linear dependence Tμ of Ф: The formula for isothermal layer (γμ=0): Air density is calculated by equation of state:

Conclusion § § § Standard Atmosphere pattern uses in atmospheric sciences for calculating, engineering and other theoretical and practical problems. Online calculators for Standard Atmosphere: http: //www. digitaldutch. com/atmoscalc/ http: //pr. erau. edu/gallyt/stdatm. html http: //www. desktop. aero/stdatm. php

References L. T. Matveev, Fizika atmosfery, Hydrometizdat, 2000 M. Cavcar, The International Standard Atmosphere, Anadolu University, 2005 http: //www. engineeringtoolbox. com/ http: //soliton. ae. gatech. edu