Physics of the Atmosphere .pdf

Chapter 8.1: Introduction 8.1 - Physics of the Atmosphere 2 Atmosphere - Chemical Composition 8.1 - Physics of the Atmosphere 3 Atmosphere – Physical Composition 8.1 - Physics of the Atmosphere 4 Atmosphere Layers...

Chapter 8.1: Introduction 8.1 - Physics of the Atmosphere 2 Atmosphere - Chemical Composition 8.1 - Physics of the Atmosphere 3 Atmosphere – Physical Composition 8.1 - Physics of the Atmosphere 4 Atmosphere Layers 8.1 - Physics of the Atmosphere 5 Pressure of the atmosphere 8.1 - Physics of the Atmosphere 6 Temperature changes in the atmosphere 8.1 - Physics of the Atmosphere 7 Effects of altitude on temperature 8.1 - Physics of the Atmosphere 8 Atmosphere physical composition 8.1 - Physics of the Atmosphere 9 Air Density 8.1 - Physics of the Atmosphere 10 Air density 8.1 - Physics of the Atmosphere 11 Air density with changing altitudes 8.1 - Physics of the Atmosphere 12 Air density with changing altitudes 8.1 - Physics of the Atmosphere 13 Air density with changing altitudes 8.1 - Physics of the Atmosphere 14 Air density of aircraft performance 8.1 - Physics of the Atmosphere 15 Water Vapour 8.1 - Physics of the Atmosphere 16 Water Vapour 8.1 - Physics of the Atmosphere 17 Humidity 8.1 - Physics of the Atmosphere 18 Absolute Humidity 8.1 - Physics of the Atmosphere 19 Relative Humidity 8.1 - Physics of the Atmosphere 20 Dew Point 8.1 - Physics of the Atmosphere 21 Dew Point 8.1 - Physics of the Atmosphere 22 Properties of a Fluid: SI System British System 1. Pressure: 2. Temperature: 3. Density: 4. Velocity: 𝑚 Τ𝑠 𝑓𝑡Τ𝑠 8.1 - Physics of the Atmosphere 23 Two unit systems 1. SI Unit (Système International d’Unités) 2. Imperial Unit SI Unit (Metric system) Imperial Unit Origin French system British System Force N (Newton) (pound force) Mass kg Slug, (pound mass) Length m, cm, mm , Time Second (s) Temperature K ( Kelvin) °R (Degree Rankin) Power W (Watt) hp (Horse power) Pressure (Pa: Pascal) Volume Viscosity 8.1 - Physics of the Atmosphere 24 Two unit systems Property Symbol SI Unit (metric system) Imperial Unit Density ρ Specific gas constant (air) R Acceleration of gravity g 8.1 - Physics of the Atmosphere 25 Specific Volume Density 1. The mass per unit volume Specific volume 1. The volume per unit mass 2. The inverse of density Equation of state 8.1 - Physics of the Atmosphere 26 Example.1 The air pressure and density at a point on a Boeing 747 are 1.1x105 N/m2 and 1.2 kg/m3, respectively. What is the temperature at that point? 𝑃 = 𝜌𝑅𝑇 𝑃 1.1 × 105 𝑇= = = 319 𝐾 𝜌𝑅 1.2 × 287 8.1 - Physics of the Atmosphere 27 Example2 The high pressure air storage tank for a supersonic wind tunnel has a volume of 1000 ft3. if air is stored at a pressure of 30 atm and a temperature of 530 R, what is the mass of gas stored in the tank in slug? In pound mass? (hint: 1 atm is 2116 lb/ft2) Solution 𝑃 = 𝜌𝑅𝑇 𝑃 30 × 2116 𝜌= = = 6.98 × 10−2 𝑠𝑙𝑢𝑔Τ𝑓𝑡 3 𝑅𝑇 1716 × 530 𝑀 = 𝜌𝑉 = 6.98 × 10−2 × 1000 = 69.8 𝑠𝑙𝑢𝑔 𝑀 = 69.8 × 32.2 = 2248 𝑙𝑏𝑚 8.1 - Physics of the Atmosphere 28 Pressure Altitude 8.1 - Physics of the Atmosphere 29  Pressure Altitude (Total Air Temperature) 8.1 - Physics of the Atmosphere 30  Pressure Altitude Pilot Co-Pilot Static port (Dassault 8.1 - Physics Falcon 50) of the Atmosphere 31  Pressure Altitude Outside air pressure Static port Pressure altitude is 3,200 m 8.1 - Physics of the Atmosphere 32  Temperature Altitude Total air temperature TAT probe Temperature altitude is 3,100 m 8.1 - Physics of the Atmosphere 33  Density Altitude Air density Density altitude is 3,400 m 8.1 - Physics of the Atmosphere 34  Density Altitude Measured property Altitude Pressure altitude 3,200 m Temperature altitude 3,100 m Density altitude 3,400 m Real altitude ? 1. Every measurement have some source of error. 2. Every parameters which displayed to pilot is not the exact value. 8.1 - Physics of the Atmosphere 35 International Standard Atmosphere (ISA) 8.1 - Physics of the Atmosphere 36 ISA Standard Conditions 8.1 - Physics of the Atmosphere 37 International Standard Atmosphere (ISA) 8.1 - Physics of the Atmosphere 38 Pressure Altitude 8.1 - Physics of the Atmosphere 39 ISA Temperature 8.1 - Physics of the Atmosphere 40 International Standard Atmosphere (ISA) Pressure (p) Altitude (h) ISA Temperature (T) Density (ρ) 1. The keystone of the ISA is a defined variation of temperature (T) with altitude (h). 2. ISA is a reference atmosphere only. 3. ISA does not predict the actual atmospheric properties that may exist at a given time and space. 4. Standard atmosphere calculator http://www.digitaldutch.com/atmoscalc/ http://aero.stanford.edu/StdAtm.html 8.1 - Physics of the Atmosphere 41 International Standard Atmosphere (ISA) Standard atmosphere calculator http://www.digitaldutch.com/atmoscalc/ 8.1 - Physics of the Atmosphere 42 International Standard Atmosphere (ISA) 8.1 - Physics of the Atmosphere 43 Effect of Temp. On takeoff run and climb rate 8.1 - Physics of the Atmosphere 44 Q Code 8.1 - Physics of the Atmosphere 45 Airspeed 8.1 - Physics of the Atmosphere 46 Conclusion 8.1 - Physics of the Atmosphere 47 8.1 - Physics of the Atmosphere 48