STANDARD ATMOSPHERE Udit Vohra Aerospace Engineering Department - PowerPoint PPT Presentation

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 Space vehicles Atmospheric vehicles To study the Vehicles which design and Vehicles which fly Why do we need fly in deep space Lets see what I in earth’s performance of to study these ? eg -satellites got for you these vehicle atmosphere only http://static1.businessinsider.com/image/5374f0df 6bb3f73f5c360e25-1200- https://iasmania.com/launch-vehicles-for-satellites-space-probes/ 1715/ap090416034735.jpg 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. Temperature. Absolute Alt. Geopotential Pressure Alt. AE-705 Introduction to Flight Lecture 01 Capsule-01

Depends on whom you ask..!! Geometric Density Alt. Temperature. Absolute 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/ Figure out yourself Geopotential altitude & is considered ONLY in Why not for atmospheric report on Moodle..!! case of space vehicles 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 AE-705 Introduction to Flight https://upload.wikimedia.org/wikipedia/commons/thumb/6/62/Comparison_International_Standard_Atmosphere_spac e_diving.svg/576px-Comparison_International_Standard_Atmosphere_space_diving.svg.png Lecture 01 geometric Variation of Altitude P and T Capsule-01 with

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= - ρ gdh p= ρ RT 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 https://www.m0a.com/calculating-density-altitude/ this graph ?? 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 Minimum temperature (Antarctic) = -75 o C  Maximum temperature (Somalia, South Africa) = + 65 o C  Earth’s surface Temperature varies from -75 o C to + 65 o 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 QNH QFE 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 • height above the station QFE 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 Turbulence Rain & Hail Microburst Windshear Clouds AE-705 Introduction to Flight Lecture 01 Capsule-01