1976 US Standard Atmosphere1 1976 U.S. Standard Atmosphere One of several models of the atmosphere. Provides dependence of temperature, pressure and density.

Slides:



Advertisements
Similar presentations
Chapter 2 - Hydrostatics
Advertisements

Aula 4 Mecânica dos Fluidos Sandro R. Lautenschlager
Pressure Volume Relationship. Objectives Explain Boyle's law. Define pressure in general terms. Compare atmospheric, hydrostatic pressure, and absolute.
Department of Mechanical Engineering ME 322 – Mechanical Engineering Thermodynamics Lecture 19 Calculation of Entropy Changes.
Hydrostatic Equilibrium Chapt 3, page 28
Cv dT = 0 - P dV = - (n R T / V) dV
ABSORPTION Beer’s Law Optical thickness Examples BEER’S LAW
MET 61 1 MET 61 Introduction to Meteorology MET 61 Introduction to Meteorology - Lecture 2 “The atmosphere (II)” Dr. Eugene Cordero San Jose State University.
ABSORPTION Beer’s Law Optical thickness Examples BEER’S LAW Note: Beer’s law is also attributed to Lambert and Bouguer, although, unlike Beer, they did.
Specific Heat Thermodynamics Professor Lee Carkner Lecture 8.
Pressure Pressure changes provide the push that drive ocean currents Key is the hydrostatic pressure Hydrostatic pressure is simply the weight of water.
MET 61 1 MET 61 Introduction to Meteorology MET 61 Introduction to Meteorology - Lecture 3 Thermodynamics I Dr. Eugene Cordero San Jose State University.
* Reading Assignments:
Module 1: Themes in Physical Geography Topic 3: Weather Unit A : Atmospheric heating, motion (winds) and moisture Unit B : Weather systems (air masses,
AE 1350 Lecture #4 PREVIOUSLY COVERED TOPICS Preliminary Thoughts on Aerospace Design Specifications (“Specs”) and Standards System Integration Forces.
Fluid Statics.
Introduction to Fluid Mechanics
Layers of the Atmosphere
NATS 101 Lecture 2 Vertical Structure of the Atmosphere.
Gas Laws. Background  The gas laws treat gases as ideal  In ideal gases, each molecule has no volume and there is no attraction between molecules.
Team Philosoraptors: Temperature, Humidity, Pressure Hannah Gardiner Joe Valieant Bill Freeman Randy Dupuis.
Atmospheric Moisture Vapor pressure (e, Pa) The partial pressure exerted by the molecules of vapor in the air. Saturation vapor pressure (e s, Pa ) The.
Road map to EPS 5 Lectures5: Pressure, barometric law, buoyancy water air fluid moves Fig. 7.6: Pressure in the atmosphere (compressible) and ocean (incompressible).
Chapter 3 Section 3 – Gas Behavior
2.1 Mixtures of Ideal Gases The partial pressure of a gas in a mixture of gases is the pressure that gas would have if it occupied the total volume of.
Chapter Fluid pressure and temperature. Pressure  What happens to your ears when you ride in an airplane?  What happens if a submarine goes.
FLUID STATICS: Hydrostatic Force on Plane Surfaces slide 18.
The Atmosphere: Part 3: Unsaturated convection Composition / Structure Radiative transfer Vertical and latitudinal heat transport Atmospheric circulation.
CHEMISTRY CONCEPTS (LAST CLASS) CHEMICAL THERMODYNAMICS: steps don’t matter  final state – initial state CHEMICAL KINETICS: rates depend on series of.
MAE 3130: Fluid Mechanics Lecture 2: Fluid Statics (Part A) Spring 2003 Dr. Jason Roney Mechanical and Aerospace Engineering.
Ozone problem Calculate the dependence of O 3 and O with altitude. In class I only showed qualitatively Use an O 2 density of n 2 (z) = n 2 (0)exp[-z/H].
HYDROS TATIC. HYDROSTATIC branch of fluid mechanics that studies fluids at rest. It embraces the study of the conditions under which fluids are at rest.
Temperature Structure of the Atmosphere Chapter 5.
Ch. 8.3 Pressure in Fluids. Pressure pressure – the amount of force applied to a given area – air, just like water, is a fluid (any substance that flows)
Dr. Kamel Mohamed Guedri Umm Al-Qura University, Room H1091
Air Temperature, Pressure, and Density
10.2 Energy Transfer in the Atmosphere
THE ATMOSPHERE (chapter 24.1)
NATS 101 Section 4: Lecture 2 Atmospheric Composition and Structure.
 Gasses make up the air around us  Primary gasses are Nitrogen and Oxygen  Small amounts of many other gasses are present.
Entropy Property Relationships Chapter 7b. The T-ds relations Consider an internally reversible process occurring in a closed system.
1 Property Relationships Chapter 6. 2 Apply the differential form of the first law for a closed stationary system for an internally reversible process.
Thermal Energy Transfer. Thermal Energy – Energy created by the movement of particles in a substance. Heat: Thermal energy that is transferred from one.
Atmosphere. What makes up our atmosphere?  Nitrogen  Oxygen  Argon.
The Atmosphere The atmosphere is the layer of gases that surrounds the Earth. Earth’s atmosphere is a mixture of nitrogen, oxygen, water vapor, and many.
ATMOSPHERIC LAYERS. TROPOSPHERE We live here! – (nearest Earth’s surface) Weather occurs here! Contains 80% of atmosphere’s mass – Airplanes require density.
IT 264 INDUSTRIAL FLUID POWER Chapter 13 Pneumatics: Air Preparation and Components.
AKM 205 AKIŞKANLAR MEKANİĞİ Yrd.Doç.Dr. Onur Tunçer İstanbul Teknik Üniversitesi “AKIŞKAN STATİĞİ”
AND THEIR FORCES Fluids. Matter that can flow is called a fluid. “Fluid” does not mean the same thing as “liquid.” Both liquids and gases are called fluids.
Gas Laws! Introduction to Gas Laws.. Key Terms  Pressure: the amount of force per unit area of surface  Newton: the SI unit for force  Pascal: the.
Atmosphere Air Pressure Local Winds Global Winds Instruments
ThermodynamicsM. D. Eastin We need to understand the environment around a moist air parcel in order to determine whether it will rise or sink through the.
Temperature Changes With Earth’s Atmosphere
Temperature Changes With Earth’s Atmosphere
Hydrostatics Dp Dz Air Parcel g.
Lab 2: Vertical Structure of the Atmosphere
GLOBAL ENERGY BUDGET - 3 Atmosphere Basics.
Earth’s Atmosphere.
CE 230-Engineering Fluid Mechanics
The Structure of the Atmosphere
Gases Boyle’s Law.
1. How many layers are there in Earth’s atmosphere
AIR TEMPERATURE.
Which temperature zone of the atmosphere contains this ozone layer?
1976 U.S. Standard Atmosphere
Static flow and Its Application
1976 U.S. Standard Atmosphere
EART30351 lecture 1.
Unit: Water and the Atmosphere Lesson 2: Air Pressure
Presentation transcript:

1976 US Standard Atmosphere U.S. Standard Atmosphere One of several models of the atmosphere. Provides dependence of temperature, pressure and density on altitude. Temperature is tabulated at 8 specific altitudes and temperatures at other altitudes, pressure and density computed from those data.

1976 US Standard Atmosphere2 For Incompressible Fluid (like Water) P1P1 P [Pascal = N/m 2 ] z Known as “hydrostatic equation” The difference in pressure at the two depth is due to the weight of the column of water between them.

1976 US Standard Atmosphere3 Atmosphere – Compressible Fluid First consider an isothermal (constant temperature) atmosphere and assume a perfect gas: Rearrange: (Perfect gas) Apply limits:

4 Atmosphere – Compressible Fluid So for isothermal (constant temperature) atmosphere: i.e., express pressure at one point in terms of that at a different altitude You can also handle (integrate) the case where the temperature is a linear function of altitude (constant “lapse rate”).* These are the two options in the VBA coding that goes with the USStandAtmos.xls spreadsheet on webpage ( Note exponential drop of pressure with altitude, vs. linear with depth in an incompressible fluid like water. *See, e.g., D.G. Shepherd, Elements of Fluid Mechanics, Harcourt, Brace and World, 1965.

1976 US Standard Atmosphere5 Red circles indicate the limits of the 7 layers. Intermediate values are computed from them.

1976 US Standard Atmosphere6 U.S. Standard Atmosphere 1976 Seven layers between sea level and ~85 km Decrease of “g” with altitude is included in the calculation by use of “geopotential” altitude. –h = Altitude * R earth / (Altitude + R earth ) Two layers are isothermal Five layers have constant “lapse rate” (dT/dz) Pressure tabulated at base of each layer and change computed between there and the point of interest. –Use equation we just derived for isothermal layer, similar equation for constant lapse rate layers. Density found from P and T and perfect gas law.

1976 US Standard Atmosphere7 Dependence of Density and Pressure On Altitude. Handy numbers to remember: 1.Density of air at sea level [kg/m3], 2.Pressure at sea level [kPa], 3.Depth of troposphere [km]. Handy numbers to remember: 1.Density of air at sea level [kg/m3], 2.Pressure at sea level [kPa], 3.Depth of troposphere [km].

1976 US Standard Atmosphere8 Other notes: Most sunlight comes through atmosphere (it’s largely transparent), hits surface of earth and the air in contact is heated up. That’s why the peak air temperature is at surface. The other temperature peak at ~50 km is due to absorption of UV rays by ozone (and there isn’t much atmosphere there to heat up).