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Standard Atmosphere AE-705: Introduction to Flight STANDARD ATMOSPHERE Udit Vohra Aerospace Engineering Department PEC University of Technology, Chandigarh AE-705 Introduction to Flight Lecture 01 Capsule-01 LAYOUT • Earth’s Atmosphere • Atmospheric Standards • Different Altitudes • Two magical equations • Q Codes for altitudes • Weather Effects http://www.newtonsapple.org.uk/earth-as-a-magnet/ AE-705 Introduction to Flight Lecture 01 Capsule-01 ATMOSPHERE http://www.slideshare.net/shalinipandey77985/res525-origin-of-earth-and -earth-atmosphere AE-705 Introduction to Flight Lecture 01 Capsule-01 AEROSPACE VEHICLES Atmospheric vehicles Space vehicles To study the Vehicles which Vehicles which fly design and WhyLets dosee we what need I fly in deep space in earth’s performance of togot study for youthese ? eg -satellites atmosphere only these vehicle http://static1.businessinsider.com/image/5374f0df 6bb3f73f5c360e25-1200- 1715/ap090416034735.jpg https://iasmania.com/launch-vehicles-for-satellites-space-probes/ AE-705 Introduction to Flight Lecture 01 Capsule-01 Why do we need ISA ? ISA (International Standard Atmosphere) Aerospace Vehicles Design and Performance determination Simulation and Analysis To relate Flight test Wind tunnel results A/C design and performance to a common reference Properties of real atmosphere Constant ISA Create a hypothetical model AE-705 Introduction to Flight Lecture 01 Capsule-01 Somebody help..!! What are they ? DIFFERENT ALTITUDES AE-705 Introduction to Flight Lecture 01 Capsule-01 Somebody help..!! Geometric Density Alt. Absolute Temperature. Alt. Geopotential Pressure Alt. AE-705 Introduction to Flight Lecture 01 Capsule-01 Depends on whom you ask..!! Geometric Density Alt. Absolute Temperature. Alt. Geopotential Pressure Alt. We will study first These will be three for now studied later AE-705 Introduction to Flight Lecture 01 Capsule-01 Indicated Altitude http://www.boldmethod.com/blog/lists/2017/05/the-5-types-of-flying-altitudes/ AE-705 Introduction to Flight Lecture 01 Capsule-01 Also called GEOMETRIC ALTITUDE Geometric Altitude/True Altitude – altitude from sea level http://www.boldmethod.com/blog/lists/2017/05/the-5-types-of-flying-altitudes/ AE-705 Introduction to Flight Lecture 01 Capsule-01 Absolute Altitude – Altitude from the center of earth Anderson-Introduction%20to%20Flight-McGraw-Hill%20Science_Engineering_Math%20(2011).pdf AE-705 Introduction to Flight Lecture 01 Capsule-01 Geopotential Altitude - variation in g is considered with the altitude h = Where h is the Geopotential altitude http://hemantmore.org/physics-1/p11202005/3898/ Geopotential altitude Figure out yourself & is considered ONLY in report on Moodle..!! case of space vehicles Why not for atmospheric vehicles?? AE-705 Introduction to Flight Lecture 01 Capsule-01 Hydrostatic Equation Fluid element at rest John%20Anderson-Introduction%20to%20Flight- McGrawHill%20Science_Engineering_Math%20(2011).pdf https://wikis.engrade.com/energyandearthsatmospher AE-705 Introduction to Flight Lecture 01 Capsule-01 Pressure, temperature, density, viscosity PARAMETER VARIATION WITH ALTITUDE AE-705 Introduction to Flight Lecture 01 Capsule-01 Lets see it layer by layer Variation of P and T with geometric Altitude Comparison_International_Standard_Atmosphere_space_diving.svg.png - e_diving.svg/576px AE-705 Introduction to Flight https://upload.wikimedia.org/wikipedia/commons/thumb/6/62/Comparison_International_Standard_Atmosphere_spac Lecture 01 Capsule-01 Temperature Variation with Altitude Atmospheric vehicles (fly at about 10km ) …so we will not consider this part Gradient layer Isothermal layer Gradient layer JohnAnderson-Introduction%20to%20Flight-McGraw- Hill%20Science_Engineering_Math%20(2011).pdf AE-705 Introduction to Flight Lecture 01 Capsule-01 P & ρ variation with altitude Isothermal Two magical equations dp= - ρgdh p= ρRT Gradient layer AE-705 Introduction to Flight Lecture 01 Capsule-01 Viscosity Sutherland’s Formula https://www.google.com/search?q=sutherland+formula+for+viscosity&source=lnms&tbm=isch&sa=X&sqi=2&ved=0ahUKEwjQ8OWao5TU AhUDq48KHb_XC9kQ_AUIBigB&biw=1408&bih=671&dpr=0.97#imgrc=Lyv9kfZ5j2KqoM:&spf=1496032614588 AE-705 Introduction to Flight Lecture 01 Capsule-01 Pressure Altitude Altitude corresponding to the pressure values in the ISA table Here – the theoretical location where at 15 degrees Celsius the altimeter setting will equal 29.92 inches of mercury Temp & pressure corrections http://www.boldmethod.com/blog/lists/2017/05/the-5-types-of-flying-altitudes/ AE-705 Introduction to Flight Lecture 01 Capsule-01 Density Altitude Pressure altitude corrected for non-standard temperature How to read this graph ?? altitude/ - density - https://www.m0a.com/calculating AE-705 Introduction to Flight Lecture 01 Capsule-01 Temperature Altitude Altitude corresponding to the temp values in the ISA table https://www.aopa.org/news-and-media/all-news/2015/april/pilot/t_mm AE-705 Introduction to Flight Lecture 01 Capsule-01 Important points Use the geometric altitude of the tables when referring to p, density, and temp altitudes Pressure altitude can be different from temp altitude and density altitude and vice-versa These altitude might differ from geometric altitude as well AE-705 Introduction to Flight Lecture 01 Capsule-01 USA, India, Arctic, Tropical, …. OTHER STANDARD ATMOSPHERES AE-705 Introduction to Flight Lecture 01 Capsule-01 Other Standard Atmospheres 1976 U.S. Standard Atmosphere https://en.wikipedia.org/wiki/U.S._Standard_Atmosphere AE-705 Introduction to Flight Lecture 01 Capsule-01 1976 U.S. Standard Atmosphere cont.. https://www.google.com/search?q=united+states+standard+atmosphere+1976&source=lnms&tbm=isch&sa=X&sqi=2&ved= 0ahUKEwjygv3XkJTUAhUMQo8KHeYeBl0Q_AUIBigB&biw=1570&bih=748#imgrc=hi4JaikQVNPzhM:&spf=1496027490886 AE-705 Introduction to Flight Lecture 01 Capsule-01 Indian Reference Atmosphere Valid in Indian Equatorial Zone from Surface to 80 km Data recorded in 1985 Series of tables containing data related to • Temperature (K) • Pressure (millibars) • Density (kg m-3) 71 64 53 32 24 https://link.springer.com/article/10.1007%2Fs00382-016-3293-2 AE-705 Introduction to Flight Lecture 01 Capsule-01 https://link.springer.com/article/10.1007%2Fs00382-016-3293-2 Monthly temperature profiles from 14 years of observations (2002-15) AE-705 Introduction to Flight Lecture 01 Capsule-01 Mumbai Weather Data (Nov 2016) Actual Data Elevation of Mumbai is 14 m AMSL https://www.timeanddate.com/weather/india/mumbai/historic?month=11&year=2016 ISA Hence, Mumbai atmosphere is ISA +14 AE-705 Introduction to Flight Lecture 01 Capsule-01 Arctic Minimum & Tropical Maximum o Minimum temperature (Antarctic) = -75 C o Maximum temperature (Somalia, South Africa) = + 65 C o o Earth’s surface Temperature varies from -75 C to + 65 C Temperature as Latitude https://www.google.com/#q=arctic+minimum+atmosphere&spf=14968184947 50 AE-705 Introduction to Flight Lecture 01 Capsule-01 Q CODES FOR ALTITUDES AE-705 Introduction to Flight Lecture 01 Capsule-01 QNH • Pressure measured at ground reduced to MSL pressure • Altitude displayed AMSL Flight level Height QFE QNH Altitude station 1013.2 elevation MSL 1013.2 AE-705 Introduction to Flight Lecture 01 Capsule-01 QFE & QNE QFE • SL pressure corrected for QNE temp for specific station ISA mean atm pressure at SL Referred as Standard QFE • height above the station QNE QNH Runway (station) 29.92’’(1013.2 hpa ) Datum SL reference Datum (adjusted) AE-705 Introduction to Flight Lecture 01 Capsule-01 Weather effects AE-705 Introduction to Flight Lecture 01 Capsule-01 Weather Effects Rain & Hail Turbulence Microburst Windshear Clouds AE-705 Introduction to Flight Lecture 01 Capsule-01 .
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