ESDU A-Z Index: V-VZ

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

| V-VZ |

Vacuum

Suitability of Various Dry Rubbing Materials for Use in: carbon, polymer, thermoset, solid lubricant impregnated metal, 87007

Vacuum Limit

Pressure Coefficient, 98026
To Wing Leading-Edge Suction: effect on lift dependent drag in subsonic flow, 95026; effect on lift dependent drag in supersonic flow, AERO W.S.02.03.02

Valves

see also: Pressure Drop in Gas- or Vapour-Liquid Internal Flow; Pressure Drop in Internal Flow

Prediction of Pressure Change in Pipeline After Closure

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

Van Dyke's Second Order Theory

Velocity Distribution: on aerofoils, 72025; on bodies, AERO B.S.02.03.01

Vanes

In Bends: design information, 83037; optimum location for one or two in circular-arc, 83037; pressure drop in circular-arc with optimum splitter location, 83037
Use to Improve Diffuser Performance: recommendations for geometry, 87015; static pressure recovery improvement achieved, 87015

Vane-Type Flowmeters

Pressure Drop Across, 66030

Vane Vortex Generators

For Control of Shock-Induced Separation: analysis of use on fuselage to control cabin noise, 87012, 93026; analysis of use on wind-tunnel wing model to decrease separation, 93026; analysis of use on wing to improve buffet manoeuvre boundary, 93026; aspect ratio, height and incidence setting for effective use, 93025; chordwise position, lateral spacing and extent of array required, 93024, 93025; consideration of contribution to drag with worked example, 93024; control of corner flow, 93024; decay and dissipation of vortices, 93024; flowchart for step-by-step guide to design of an array, 93025; limits of possible control on aerofoils and wings, 93024, 93025; possible multiple arrays, 93024; use in combination with fences, 97017; use of wind-tunnel tests to assess effectiveness, 93024; vortex path and effect of mixing for counter-rotating array, 93024; vortex path, spacing and decay for co-rotating array, 93024
Use to Improve Diffuser Performance: recommendations for geometry, 87015; static pressure recovery improvement achieved, 87015

Vaporisers

see: Boiling Flow in Pipes; Falling Film Evaporation

Variable Area Flowmeters

Pressure Drop Across, 66030

Vectored-Jet-Thrust Aircraft

see also: Interference; Ski-Jump Performance; Take-Off

Appropriate Non-Dimensional Quantities for Performance, 87037: derivation for partially-jet-borne flight and for short take-off, 87037
Jet-Induced Aerodynamic Effects: lift-loss in free-air hover and forward flight, 87037
Use of Free-Air Hover Weight as Performance Parameter, 87037
Use of Partially-Jet-Borne Flight Test Results in Performance Estimation, 87037

Velocities

Axes Transformation, 67004, 67036, 78038, 85030, 86041, 98024

Measurement in Flight

see: Anemometric Data Correction

Relationship Between Air-Path, Flight-Path and Wind, 79018

Velocity Distribution

see also: Pressure Distribution

Aerofoils: program to predict for low-drag GUNACA-series, 99003
Bodies of Revolution at Zero Incidence: variation with body geometry, 78037; variation with flow conditions, 78037
In Wake Behind Wing, AERO W.05.01.01
Two-Dimensional Circular-Section Cylinders Normal to Flow: mean values in flow away from surface, 80025

Velocity Profile

see also: Boundary Walls and Fences; Hoardings (Elevated Above Ground Level); Profile Factors

Calculation for Wind Near Ground, 01008, 82026, 84011

effect of topographical features, 01008, 82026

effect of upwind terrain roughness, 01008, 82026, 84011

over specific terrains, 70015, 71016, 79026, 80003, 81017

program, 01008

Effect of Upstream and Downstream on Static Pressure Loss in Incompressible Flow

through sudden contraction of duct area with or without edge rounding, 05024

Effect on Mean Forces, Moments and Pressures on Bluff Bodies

see: Shear Flow

Effect on Noise Measurements Near Ground, 89036

program

Effect on Sound Power Attenuation in Lined Annular or Rectangular Straight Ducts

with subsonic flow, 00024

Effect on Sound Power Attenuation in Lined Circular Straight Ducts

with subsonic flow, 00012

Naturally-Developed Flow

effect on performance of annular diffusers, 75026

effect on performance of conical diffusers in compressible flow, 90025

effect on performance of conical diffusers in incompressible flow, 73024

effect on performance of plane-walled diffusers, 74015

effect on performance of sudden enlargement of section, 72011

Naturally-Developed Flow in Circular-Section Ducts

kinetic energy coefficient at various stations, 73024

Naturally-Developed Flow in Rectangular- or Square-Section Ducts

blockage parameters at various stations, 74015

Non-Naturally-Developed Flow

effect on performance of diffusers, 76027

Ventilated Wind-Tunnels

see: Wind-Tunnel Corrections for Aerofoils; Wind-Tunnel Testing

Ventilating Systems

see: Cooling and Ventilation Systems; Noise in Air-Conditioning Duct Systems

Venturi Tubes

Pressure Drop Across, 66030

VGK

see: Garabedian and Korn Method

The estimation of turbulent boundary layer power-law velocity and q profiles from shape factor and momentum thickness, 18009

Vibration and Acoustic Fatigue Series

Location of Items in ESDU Series, 00011
Record of Amendments to Items in ESDU Series, 00011

Vibrations

see: Box Structures; Buildings; Crossflow Heat Exchangers; Curved Rectangular Plates; Curved Sandwich Panels (Cores of Negligible Flexural Stiffness); Curved Specially-Orthotropic Rectangular Plates; Cylinders of Circular Section (Strength and Vibration); Damping; Double Lock Nuts; Flat Panels in General; Flat Rectangular Plates; Flat Sandwich Panels (Cores of Negligible Flexural Stiffness); Flat Specially-Orthotropic Rectangular Plates; Flat Specially-Orthotropic Square Plates; Flat Square Plates; Force Limited Random Vibration Testing; Frequency; Modal Density; Modes; Noise; Noise in Air-Conditioning Duct Systems; Non-Destructive Examination; Pipes with Internal Flow; Random Vibrations; Response; Response of Buildings and Structures; Response of Buildings and Structures To Atmospheric Turbulence; Response of Buildings and Structures To Vortex Shedding; Response of Lightweight Structures; Shafts; Shell-And-Tube Heat Exchangers; Vibration and Acoustic Fatigue Series

View Factors

see: Radiation Heat Transfer

Viscometers

Types Available to Characterise Rheological Behaviour of Non-Newtonian Fluids: advantages and disadvantages of each, 95012; calculation of shear stress and shear rate, 95012; coaxial cylinder, cone and plate, parallel plate, rotating disc, tube, 95012; criteria for selection of appropriate type, 95012; errors and their correction, 95012

Viscoplastic Fluid

see: Non-Newtonian Fluids

Viscosity

see also: Dynamic Viscosity; Kinematic Viscosity; Non-Newtonian Fluids

Index: definition, 68036, 71003; table of values showing relationship with kinematic viscosity, 71003

Viscous Full Potential

Full-Potential (FP) Method for Three-Dimensional Wings and Wing-Body Combinations - Inviscid Flow: evaluation of trailing-vortex drag and wave components, 06016; full-potential with frozen boundary layer, 11007; method with improved estimates of body lift and drag contributions (FPIBE), 06015; pre-processor to represent effect of fore- and aft-body shape on wing flow, 10014; Principles and results, 02013; use of FP and related programs, 02014
Viscous Full-Potential (VFP) Method for Three-Dimensional Wings and Wing-Body Combinations: excrescence drag modelling, 23013, TM 214; use of VFP and related programs, 13012; validation of VFP results with experiment and comparisons with other methods, 13013; VFP error messages, failures and suggested remedies, 13014