Flight Systems Units of Measure Guidelines.

$Revision: 79 $
$Date: 2005-01-21 14:45:19 -0500 (Fri, 21 Jan 2005) $
Written by: Geoff Brian ([email protected])

Table of Contents

  1. Introduction
  2. Comments
  3. Units of Measure Abbreviations
  4. References

Introduction

This document, although not exhaustive, lists abbreviations for units of measure common in the Aircraft Modelling and Simulation community.

Aircraft flight simulations and models compute the behaviour of the aircraft subject to stimuli such as flight control system inputs and environments influences. They also rely on a representation of the physical properties of the aircraft such as its aerodynamics, propulsion system and mass properties. Data detailing the inputs and outputs from simulations, as well as the physical properties of the aircraft, have different units of measure, and also may be mixed between Système Interationale (SI) units and Imperial units. This guideline presents the units of measure for data utilised by aircraft simulations and models developed by Flight Systems, Air Vehicles Division, DSTO. The Flight Systems Units of Measure Guideline is based on the AIAA Modeling and Simulation Technical Committee "Standards for the Exchange of Simulation Modeling Data -- Preliminary Draft", [1].  

Comments

  1. Data may have a base unit of measure, as shown in following table, or may be a combination of units; for example, metre: m or acceleration: m s-2.
  2. The prefix abbreviations are applied to the base unit of measure abbreviation, and scale the data using values in the comment box; for example, millimetre: mm = 10-3 m
  3. For data that have a combined unit of measure, they will be defined using base units elements separated by a blank space; for example, fuel flow rate:  l s-1
  4. Divisor units of measure are represented by the unit abbreviation raised to the equivalent negative power; for example, feet per second is represented as ft s-1 
  5. Velocity is generally represented using a combined unit of measure; for example, m s-1. However, the knot is a recognised measure in the aviation community and thus included.

Units of Measure Abbreviations

SI - Système Interantionale

    Measure Abbreviation Comments
      General    
         non-dimensional ND Used if non-dimensional parameter
         
      Prefix 2    
         tera T 1012 * parameter
         giga G 109 * parameter
         mega M 106 * parameter
         kilo k 103 * parameter
         deci d 10-1 * parameter
         centi c 10-2 * parameter
         milli m 10-3 * parameter
         
      Time    
         Solar year yr  
         Solar day day  
         hour h  
         minute min  
         second s SI Standard
         
      Length    
         metres m SI Standard
         inch in  
         feet ft  
         yard yd  
         nautical mile nmi  
         statute mile smi  
         
      Velocity 5    
         knot kn nmi h-1
         
      Volume    
         litre l 10-3 m3
         US gallon USgal  
         UK gallon UKgal Imperial Gallon
         
      Mass    
         kilogram kg SI Standard -- 103g
         gram g  
         tonne tonne  
         slug slug  
         short ton USton US Ton 
         long ton UKton UK Ton
         
      Force    
         Newton N SI Standard
         Pound Force lbf  
         
      Pressure    
         Pascal Pa N m-2
         millimetres Mercury mmHg  
         Pounds per square foot lbf ft-2 lbf ft-2
         Pounds per square inch lbf in-2 lbf in-2
         inches Mercury inHg  
         Atmosphere atm  
         
      Temperature    
         degrees Kelvin K SI Standard
         degrees Centigrade C  
         degrees Farenheight F  
         degrees Rankin R  
         
      Viscosity    
         Poise Ps Dynamic viscosity 
         Stokes St Kinematic viscosity
         
      Plane Angle    
         degree deg  
         radian rad  
         revolution rev  
         
      Power, Energy    
         Watt W SI Standard
         horsepower hp 550 ft lbf s-1
         joule jou SI Standard
         British thermal unit btu  
         calorie cal  
         erg erg  
         
      Electrical, Magnetic    
         volt direct current Vdc  
         volt alternating current Vac  
         ampere A SI Standard
         omh, resistance ohm SI Standard
         cycle cyc  
         henry hy  
         farad fd  
         Telsa T field strength
         

References

  1. "Standards for the Exchange of Simulation Modeling Data", Preliminary Draft, 9 June 1997, AIAA Modeling and Simulation Technical Committee.
  2. "SI Units Dimensional Analysis &, Chapter 8 Figure -- Conversion Tables", McMahonlines, MathTech Reference Series.
  3. http://www.unc.edu/~rowlett/units/index.html

     

 

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Last modified Sun, 25-Apr-2010