Aircraft_perf_notes1

Aircraft_perf_notes1 - NEXTOR - National Center of...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: NEXTOR - National Center of Excellence for Aviation Research 1 Analysis of Air Transportation Systems Fundamentals of Aircraft Performance (1) Dr. Antonio A. Trani Professor of Civil and Environmental Engineering Virginia Tech Fall 2010 Blacksburg Virginia Tech - Air Transportation Systems Laboratory 2 Introductory Remarks Air vehicles are signi f cant different than their ground vehicle counterparts in three aspects: Most aircraft require a prepared surface to operate from which affects the overall capability of the vehicle to carry useful payload Aircraft operate in a dynamic atmospheric environment where changes in temperature, density, and speed of sound are drastic and cannot be neglected Aircraft mass expenditures are signi f cant and thus need to be accounted for in the air vehicle performance analysis. For example, a Boeing 747-400 can takeoff at near 390 metric tons and yet land at its destination at 220 Virginia Tech - Air Transportation Systems Laboratory 3 metric tons thus making the fuel expenditure a signi f cant factor in how the vehicle performs along the F ight path The analysis of NAS performance is related to the performance of the vehicles operating in it (i.e., airport runway and airspace sector capacity depends on aircraft characteristics) The analysis of airline operations requires a careful examination of the aircraft performance that matches a speci f c route segment (i.e., DOC, travel time, seating capacity, etc.) Virginia Tech - Air Transportation Systems Laboratory 4 Aircraft Performance Basics (International Standard Atmosphere) Virginia Tech - Air Transportation Systems Laboratory 5 Assumptions of the International Standard Atmosphere Linear variation in temperature with altitude up to 11,000 meters (Troposphere) Constant temperature betwen 11,000 and 82,300 ft (25.1 kilometers) in the so-called stratosphere region Linearly increasing temperature from 82,300 ft. and above Most of the analysis we do in this class requires knowledge of temeperature variations up to 15,600 meters (51,000 ft.) thus only the f rst two layers of the atmosphere are of interest to us Virginia Tech - Air Transportation Systems Laboratory 6 Basic Relationships to Uderstand the Atmosphere Equation of state: (1) where: is the air pressure (N/m 2 ), is the universal gas constant (287 N-m/ o K), is the air density (kg/m 3 ), and is the absolute air temperature ( o K) p ! RT = p R ! T Virginia Tech - Air Transportation Systems Laboratory 7 Basic Relationships (Hydrostatic Equation) the hydrostatic equation that relates air pressure, density and height above sea level of a f uid is, (2) where: is rate of change in air pressure, is the gravity constant (9.81 m/s 2 ), is the air density (kg/m 3 ), and is the altitude of the f uid element above sea level conditions (m) Note: For derivations of these equations consult any f uid dynamics textbook or aerodynamics text dp ! gdh = dp g !...
View Full Document

Page1 / 130

Aircraft_perf_notes1 - NEXTOR - National Center of...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online