ESDU A-Z Index: FLE-FORF

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Flexibility

Aircraft

see: Static Aeroelasticity

Strength Analysis

see: Bolted Joints; Bolted Lap Joints; Pipe Bends (unrestrained); Pipe Bends (with End Flanges); Pipe Bends (with Straight Pipe Attachments); Shear Webs

Flexural Buckling

see also: Flat Panels in General

Flat Panels Under Compression

description, 72012

Struts Under Compression

see: Struts in General; Struts of Channel Section; Struts of Lipped or Unlipped Z-Section; Struts of Thin-Walled Open Section

Flexural Properties

see: Angle Sections with Lips; Channel Sections with Lips turned inwards; Channel Sections without Lips; Laminated Construction Using Composites; Z-Sections

Flexure-Pivots

Crossed Strip: angular spring rate, 67021; applications, 67021; buckling criterion, 67021; deflection, 67021; design procedure, 67021; load capacity, 67021

Flight Dynamics

see: Aerodynamic Loading; Ailerons; Attitude Angles; Axes Systems in Aircraft Dynamics and Performance; Control Systems; Direction Angles; Dutch Roll; Dynamic Stability; Equations of Motion; Handling Qualities; Incidence Angles; Lateral Stability and Response; Linear Systems; Longitudinal Stability and Response; Non-Linear Systems; Notation; Parameter Identification; Rolling; Rudder; Sampled-Data Systems; Static Aeroelasticity

Flight Effects on Noise Measured Under Static Conditions

see also: Jet Noise

Discussion of Changes to Various Noise Sources, 02020: Doppler frequency shifting due to aircraft velocity, 02020

Flight Envelope

Typical and Load Factor Values for Various Aircraft Types, 94009

Flight Instrumentation

see: Ambient Temperature; Anemometric Data Correction

Calibration of Pressure Air Data Systems, 20006
In-flight calibration of an angle of attack sensor, 17013, TM 185
Parameters measured and recorded during flight test manoeuvres in order to derive performance model, 15001

Flight Path

see also: Air Path; Flight Path Optimisation

Constraints on Climb and Descent Due to Rate of Change of Cabin Pressure, 94040
Introduction to Estimation, 80026
Relationship of Velocity With Air-Path Velocity and Wind Velocity, 79018

Flight Path Optimisation

see also: Cruise-Climb

Climb Using Energy Height Techniques: calculation method for rapid estimation by personal computer, 91016; calculation methods, 90012, 91016; calculation method using flight test level accelerations, 70023; comparison of results with those from a multivariate gradient-search method, 93021; effect of using practical off-optimum climb schedule, 90012; estimation of effect of required simplifications on results, 90012; introduction to method and required simplifications of equations of motion, 90012; likely errors caused by assumptions intrinsic to method, 90012; worked example of time to height showing effect of weight change, 70021; worked examples of time and fuel to height and speed, 90012, 91016; worked examples of time and fuel to height, speed and distance, 90012, 91016
Discussion of Use of Mutivariate Gradient-Search Techniques: basis of method and need to set tolerance on result, 94012; difficulties in application with specific examples, 94012; need for user-written routines to calculate flight path segments, 94012; operation of program RQPMIN, 94012
Examples of Mutivariate Gradient-Search Applied to Complete Sortie (Climb, Cruise, Descent, Hold, etc): to maximise range under chosen design and operational constraints, 94016; to maximise various objective functions under various design and operational constraints, 93021
General Introduction to Data Items on, 80026
Introduction to General Cases, 89015: simplifications possible to achieve practical solutions, 89015

Flight Testing

see also: Aircraft Performance Analysis; Aircraft Performance Reduction; Ambient Temperature; Anemometric Data Correction; Helicopter Performance Analysis; Parameter Identification; Vectored-Jet-Thrust Aircraft

Derivation of Indicated True Airspeed, TM 199
Determination of True Airspeed and Wind Speed from Flight Test Data, 20007
Development of mathematical model from flight test data, 15001
In-flight calibration of an angle of attack sensor, 17013, TM 185
Methods of Processing Performance Data, 80009: factors affecting choice of method, 80009
Performance Data from Manoeuvring Flight, TM 190
Thrust-drag Accounting From Flight Test Data, 16003

Float-Type Flowmeters

Pressure Drop Across, 66030

Flooded Runways

see: Aircraft Tyres

Analysis of Aircraft Tests on Flooded Runways, TM 192

Flow in Piping Systems

see: Pipes with Internal Flow

Flow Measurement

Laser-Doppler Anemometry (LDA), 16001, 17008
Particle Image Velocimetry (PIV), 16001, 17009
Thermal Anemometry (CTA), 16001, 16002

Flowmetering Devices

Classification of Types, 66030
Estimation of Pressure Drop Across, 66030

Flow Separation

see also: Buffeting; Lift-Curve Slope; Maximum Lift

Aerofoils at Subcritical Speeds

characteristics, 66034, 84026, 87012, 94026

effect on lift-curve slope, 66034, 94026

prediction of leading-edge, 88030

prediction of trailing-edge, 88030

Aerofoils at Transonic Speeds

see also: Stratford's Criterion for Flow Separation

application of VGK for separation prediction, 97030

boundary layer criteria for shock-induced separation on upper-surface, 81020

characteristics, 87012, 90008

comparison of results obtained using VGK with experimental data, 97030

criteria for shock-induced flow breakdown, 91021

discussion of shock-induced separation types, 90008

flow breakdown boundary from pressure distribution and boundary layer characteristics, 91021

illustration of shock-induced separation types, 90008

reattachment point on upper surface, 91021

separation boundary from computed pressure distribution, 92008

separation boundary from computed pressure distribution and boundary layer, 81020, 97030

shock/boundary layer interaction length, 90008

shock-induced bubble length, 90008, 91021

upstream Mach number for flow breakdown, 90008, 91021

Area or Mass Flow Ratio for Onset of Intake Spillage

on conical cowls, 84004

on elliptical, parabolic and other cowls, 84004

on NACA 1-Series cowls, 81024, 84004

Concept and Preliminary Design Examples of Applying Rapid Aerodynamic Analysis Tools to Three Classic Historical Configurations Designed to Similar Requirements, TM 207

Control of Shock-Induced

see: Vane Vortex Generators

Crossflow About Bluff Bodies

see also: Critical Conditions in Fluid Flow; Vortex Shedding

discussion of fluctuating forces, 77032

Cylindrical Body at Angle of Attack, 89014

effect of Reynolds number on flow regimes, 89014

vortex separation points in supersonic flow, 91042

Description of Process, 71012

Diffusers

critical geometries for annular, 75026

critical geometries for conical, 73024

critical geometries for plane-walled with single-plane expansion, 74015

discussion of methods of control and their effectiveness, 76027

Induced on Afterbody by Underexpanded Propulsive Jet

discussion of phenomenon, 99010

Over Topographical Features

effect on wind speed-up factors, 01008, 91043

Validation

against RAE Model W4, 13013

of pressures and integral boundary layer data against M2155, 13013

Viscous Full-potential (VFP) Method for Three Dimensional Wings and Wing-Body Combinations

VFP analysis programs for flow breakdown and forces and loads, 21002

Wings at Subcritical Speeds

prediction of leading- or trailing-edge on plane or cambered and twisted, 88030

Wings at Transonic Speeds

criteria for shock-induced flow breakdown, 91021

flow breakdown boundary from pressure distribution and boundary layer characteristics, 91021

Fluids

Physical Properties

see: Non-Newtonian Fluids

Fluid Transients

see: Pressure Transients in Gas (and Steam) Internal Flow; Pressure Transients in Liquid Internal Flow

Fluorescence

Laser Induced for Temperature Measurement of Gases

see: Temperature Measurement

Flushing Oils

Kinematic Viscosity: typical values, 71003

Flush Intakes

see: Intakes; Spillage Drag

Flutter

see also: Flutter Derivatives

Classical and Stall: discussion of sources and methods of alleviating, 77032
Classical Due to Wakes: characteristics of response of a cylinder, 79025; regions of interference between two cylinders, 79025
Introduction to Calculation of Unsteady Aerodynamic Data for, 82020

Flutter Derivatives

Aerofoil Oscillating in Heave or Pitch or With an Oscillating Control

see also: Pressure Distribution

forces and moments as functions of Mach number and frequency, 81034, 82005

lift, pitching moment and hinge moment in subsonic flow, 81034

lift, pitching moment and hinge moment in supersonic flow, 82005

use of aerofoil data in wing flutter calculations, 81034

Bodies of Revolution Oscillating in Bending, Heave or Pitch

lift distribution and pitching moment as functions of frequency, 83010

Relationship With Airforce Coefficients, 81034, 83010

Use to Predict Flutter, 81034, 82020

Flying Qualities

see: Handling Qualities

Flypast

Use of to Determine Pressure Error Correction Coefficient, 20006

Fohn Winds

Description, 87034

Force Balancing of Linkages

see also: Balancing of Linkages; Linkages

Advantages and Limitations of Various Methods Singly or in Combination: counterweights, 89043; duplicate linkage added antisymmetrically or with mirror-image symmetry, 89043; dyad added, 89043; Lanchester balancer, 89043
Design Procedure for Elimination of Shaking Force on Planar Multi-Bar Linkages: determination of masses and their locations, 89028; use of OSMEC program to determine masses and their locations, 97026
Use of Constant Speed Rotating Counterweights For Partial Balance of Planar Linkages: alignment and mass of generalised Lanchester Balancer, 90007; alignment and mass of Lanchester Balancer, 90007; alignment and mass of single counterweight, 90007

Forced Convection Heat Transfer

see also: Crossflow Heat Exchangers; Heat Exchangers; Roughness; Shell-And-Tube Heat Exchangers

Annular-Section Pipes With Uniform or Varying Axial Heat Flux, 81045: criteria for negligible effects of free convection, 81045; eccentricity effects, 81045; entrance effects, 81045; variable fluid property effects, 81045
Archimedian or Helical Coils, 78031: criteria for applicability of data for straight ducts, 78031; criteria for negligible effects of free convection, 78031; non-circular cross-section effects, 78031; pitch effects, 78031; thermal entrance effects, 78031; variable fluid property effects, 78031; variation of heat transfer around circumference, 78031
Between Parallel Plates With Uniform or Varying Axial Heat Flux, 81045
Circular-Section Cylinders or Tubes in Crossflow: approximate equation for atmospheric air, 78029; effect of number of rows in bank, 73031; effect of tube bank arrangement and geometry, 73031; gases and liquids about single tube, 69004; gases and liquids through tube bank, 73031; orientation effects for single tube, 69004; orientation effects for tube bank, 73031; row-to-row variation through tube bank, 73031; variable fluid property effects for single tube, 69004; variable fluid property effects for tube bank, 73031
Colburn j-Factor Used to Model Inside Tubes: approximate expressions for various types of tube inserts, 97007; definition, 97007
Discussion of Aerodynamic Heating and Equilibrium Surface Temperature, 69009, 89022
Enhancement by Use of Roughness Elements: calculation of effect of random or systematic roughness from known friction factor, 82021; random or systematic roughness in turbulent flow, 82021; twisted tape inserts, 00041, 95027, 97007; various types of tube inserts including twisted tapes, 00041, 97007
Flat Plates at Incidence in Supersonic Flow: laminar boundary layer, 69010; turbulent boundary layer, 69011
Flat Plates at Zero Incidence in Subsonic or Supersonic Flow: application to circular-section cylinders at zero incidence, 69010, 69011; application to cones and wedges at zero incidence in supersonic flow, 69010, 69011; laminar boundary layer, 69010; turbulent boundary layer, 69011
Flow in Circular-Section Pipes: charts for rapid evaluation for steam or water, 81044; gases, 92003, 93018, AERO 00.02.05; liquids, 92003, 93018
Flow in Non-Circular Section Ducts: gases, AERO 00.02.05
High-Fin Tubes in Crossflow: comparison of predictions with experimental results, 86022; effect of number of rows in bank, 86022; effect of tube bank arrangement and geometry, 86022; effect of variable fluid properties for flow through bank, 86022; single-phase gas or liquid flow through bank, 86022
Laminar Flow in Circular-Section Pipes With Combined Forced/Free Convection, Uniform Wall Temperature: horizontal pipes, 93018; vertical pipes, buoyancy-assisted or -opposed, 93018
Laminar Flow in Circular-Section Pipes With Uniform Wall Temperature or Uniform Heat Flux: effect of radial variation of liquid viscosity, 93018; fully-developed, thermally-developing or simultaneously-developing entrance flow, 93018
Low-Fin Tubes in Crossflow: comparison of predictions with experimental results, 84016; effect of number of rows in bank, 84016; effect of tube bank arrangement and geometry, 84016; effect of variable fluid properties for flow through bank, 84016; single-phase gas or liquid flow through bank, 84016
Recovery Temperature in Gas Flow: variation with Mach number and temperature, AERO W.S.00.03.18
Rotating Shafts in Crossflow: approximate equations for atmospheric air, 78029, 97019
To or From Shapes Approximating Rectangular Bodies: approximate equation for atmospheric air, 78029, 97019
Transitional Flow in Circular-Section Pipes: recommendations for interpolating between laminar and turbulent flow, 93018
Turbulent Flow in Circular-Section Ducts, 92003, AERO 00.02.05, AERO 00.03.26: accuracy of six estimation equations in various Reynolds-Prandtl number regimes, 92003; charts for rapid evaluation for steam or water, 81044; compressibility effects, AERO 00.02.05; distribution of Nusselt number in thermally- or simultaneously-developing flow, 93018; distribution of Stanton number in thermally-developing flow, AERO 00.02.05; free convection effects, 93018; graphical comparison of six estimation equations, 92003; Petukov equations for estimation, 92003; Reynolds-Prandtl number regime for existence, 92003; thermal entrance lengths for various Reynolds-Prandtl number regimes, 92003; variable fluid property effects, 92003, AERO 00.02.05; variable heat flux distribution, AERO 00.02.05, AERO 00.03.26
Turbulent Flow in Non-Circular Section Ducts, AERO 00.02.05: compressibility effects, AERO 00.02.05; thermal entrance effects, AERO 00.02.05; variable fluid property effects, AERO 00.02.05; variable heat flux distribution, AERO 00.02.05, AERO 00.03.26

Force Limited Random Vibration Testing

JAXA Force Limits, 19006
Notching, 19006
Two Degree of Freedom System, 19006

Forces

Aerodynamic

concept and preliminary design examples of applying rapid aerodynamic analysis tools to three classic historical configurations designed to similar requirements, TM 207

expressed as an expansion in terms of small perturbations, 67003, 86021

functional dependence, 86021

Viscous full-potential (VFP) method for three dimensional wings and wing-body combinations - VFP analysis programs for flow breakdown and forces and loads, 21002

Axes Transformation, 67004, 67036, 78038, 82031, 85030, 86041

Contact

see: Contact Phenomena

Due to Internal Flow

see: Pipes with Internal Flow

On Aircraft and Components

see: Aerodynamic Loading; Axial Force; Base Drag (without Blowing or Jet Efflux); Base Drag with Central Propulsive Jet; Drag; Flutter Derivatives; Ground Performance in Take-Off and Landing; Interference; Lift; Sideforce; Similarity Laws; Thrust of Turbo-Fan and Turbo-Jet Engines

On Bearings in Planar Multi-Bar Linkages

analysis using OSMEC program, 97026

worked example to illustrate use of OSMEC program to calculate, 98023

On Buildings and Structures Due to Wind or Other Fluid Flows

see: Axial Force; Boundary Walls and Fences; Derivatives; Hoardings (Elevated Above Ground Level); Normal Force; Profile Drag; Response of Buildings and Structures To Atmospheric Turbulence; Sideforce

Forebody

see also: Cones; Cowls

Blunted

description of flow development with increasing Mach number, 82018

Blunted Conical

axial pressure force at low incidence in transonic flow, 89033

foredrag (pressure drag and skin friction) at zero incidence in supersonic flow, 68021

geometrical relations for spherical blunting, 68021, 77028, 82018, 82028, 83017

normal-force-curve slope at zero incidence and Mach numbers to 5, 89008

normal pressure force at low incidence in transonic flow, 89033

optimum blunting for minimum pressure drag, 89033

pitching-moment-curve slope at zero incidence and Mach numbers to 5, 89008

planform area and its centroid, 77028

pressure distribution at zero incidence in hypersonic or supersonic flow, 82018

pressure distribution at zero incidence in subsonic or transonic flow, 83018

pressure (or wave) drag at zero incidence in high supersonic or hypersonic flow, 82028

pressure (or wave) drag at zero incidence in transonic flow, 83017, 89033

surface area and volume, nose angle or radius of curvature, 77028

Blunted Paraboloid

geometrical relations for spherical blunting, 79004

planform area and its centroid, 77028

pressure distribution at zero incidence in transonic flow, 80008

pressure (or wave) drag at zero incidence in transonic flow, 79004

surface area, nose angle or radius of curvature, 77028

volume, 77028, 79004

Blunted Tangent or Secant Ogive

geometrical relations for spherical blunting, 77028, 82018, 83017

planform area and its centroid, 77028

surface area and volume, nose angle or radius of curvature, 77028

Conical

see also: Boundary Layer; Equilibrium Surface Temperature; Forced Convection Heat Transfer; Skin Friction Drag

foredrag (pressure drag and skin friction) at zero incidence in supersonic flow, 68021

pressure distribution at zero incidence in subsonic or transonic flow, 83018

pressure (or wave) drag at zero incidence in high supersonic or hypersonic flow, 82028

pressure (or wave) drag at zero incidence in transonic flow, 83017

Cowl

Cowl afterbody forces, 16003

Cowl forebody forces, 16003

Ducted Conical or Parabolic

external wave drag at zero incidence, AERO B.S.02.03.02

Ducted Elliptical Cross Section

external wave drag at zero incidence, AERO B.S.02.03.02

Ellipsoidal

geometrical relations, 82018

normal-force-curve slope at zero incidence and Mach numbers to 5, 89008

pitching-moment-curve slope at zero incidence and Mach numbers to 5, 89008

planform area and its centroid, 77028

pressure distribution at zero incidence in hypersonic, subsonic or supersonic flow, 82018

pressure distribution at zero incidence in transonic flow, 80008, 82018

pressure (or wave) drag at zero incidence in hypersonic, subsonic or supersonic flow, 80021

pressure (or wave) drag at zero incidence in transonic flow, 79004

surface area, nose angle or radius of curvature, 77028

volume, 77028, 79004

Flat-Faced

pressure distribution at zero incidence in hypersonic or supersonic flow, 82018

pressure (or wave) drag at zero incidence in hypersonic or supersonic flow, 82028

pressure (or wave) drag at zero incidence in hypersonic, subsonic or supersonic flow, 80021

Flat-Faced With Shoulder Radius

pressure (or wave) drag at zero incidence in hypersonic, subsonic or supersonic flow, 80021

Hemispherical

foredrag (pressure drag and skin friction) at zero incidence in supersonic flow, 68021

pressure distribution at zero incidence in hypersonic or supersonic flow, 82018

pressure distribution at zero incidence in subsonic flow, 82018, 83018

pressure distribution at zero incidence in transonic flow, 80008, 82018, 83018

pressure (or wave) drag at zero incidence in hypersonic or supersonic flow, 82028

pressure (or wave) drag at zero incidence in hypersonic, subsonic or supersonic flow, 80021

pressure (or wave) drag at zero incidence in transonic flow, 79004, 83017

Introduction to Estimation of Wave Drag, AERO B.S.02.03.01

Ogive

pressure distribution in supersonic flow, AERO B.S.05.03.01

Ogive With Nose Blunting

axial pressure force at low incidence in transonic flow, 89033

normal pressure force at low incidence in transonic flow, 89033

optimum blunting for minimum pressure drag, 89033

pressure (or wave) drag at zero incidence in transonic flow, 89033

Ogive With or Without Nose Blunting

geometrical relations for spherical blunting, 77028, 79004, 82018, 83017

normal-force-curve slope at zero incidence and Mach numbers to 5, 89008

pitching-moment-curve slope at zero incidence and Mach numbers to 5, 89008

planform area and its centroid, 77028

pressure distribution at zero incidence in subsonic flow, 82018, 83018

pressure distribution at zero incidence in transonic flow, 83018

pressure (or wave) drag at zero incidence in subsonic or supersonic flow, 80021

pressure (or wave) drag at zero incidence in transonic flow, 79004, 83017

surface area, nose angle or radius of curvature, 77028

volume, 77028, 79004

Planform Areas and Their Centroids for Various Shapes, 77028

Spherically-Curved Face With Sharp Shoulder

pressure distribution at zero incidence in hypersonic or supersonic flow, 82018

pressure (or wave) drag at zero incidence in hypersonic or supersonic flow, 82028

Spherically-Curved Face With Shoulder Radius

pressure distribution at zero incidence in hypersonic or supersonic flow, 82018

Surface Area, Nose Angle or Radius of Curvature for Various Shapes and Cross-Sections, 77028

Volume for Various Shapes, 77028, 79004

Forebody-Afterbody

see also: Cone Cylinders; Forebody-Cylinders; Interference Wave Drag; Ogive Cylinders

Planform Areas and Their Centroids for Various Shapes, 77028
Surface Areas and Volumes, Nose and Tail Angles or Radii of Curvature for Various Shapes, 77028

Forebody-Cylinders

see also: Base Drag (without Blowing or Jet Efflux); Base Drag with Central Propulsive Jet

Centre of Pressure, Normal Force and Pitching Moment: incidences to 90? and Mach numbers to 5, 89014, 90034
Normal-Force-Curve and Pitching-Moment-Curve Slopes: zero incidence and Mach numbers to 5, 89008
Oscillating in Bending, Heave or Pitch: lift distribution and pitching moment, 83010
Pitching Moment Derivatives Due to Rate of Pitch and Acceleration in Heave: low incidence and supersonic speeds, with or without boat-tailing and fins, 91004
Planform Areas and Their Centroids for Various Shapes, 77028
Sideforce at Mach Numbers Below 1.2 and Incidences Above 20?: discussion of sources, 89014; effect of Mach number and Reynolds number, 89014; effect of nose blunting, 89014; envelope of overall maximum with crossflow Mach number, 89014; typical axial distributions, 89014
Surface Areas and Volumes, Nose Angles or Radii of Curvature for Various Shapes, 77028

Foreplanes

see: Wings

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