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valve lift
valve lift Total linear motion of poppet valve, ie cam
stroke × mechanical advantage of valve gear.
valve line Cord operating aerostat gas valve.
valve petticoat See petticoat.
valve ports Inlet and exhaust passages forming part of
cylinder head.
valve rigging Linkage inside aerostat (airship) envelope
by means of which automatic valve is opened.
valve seat Angled ring, usually made of hard erosionresistant
material, forming poppet-valve mating face in
cylinder head.
valve-seat recession Accelerating erosion of pistonengine
poppet-valve seat caused by fragments of soft seat
fuzing to valve [avoided by leaded fuel or LRP].
valve timing Exact plot of crankshaft angular positions
at which piston-engine valves open and close.
VAM 1 Variable aerofoil mechanism; usually infinitely
reprofilable leading edge.
2 Visual anamorphic movie; external-scene (OTW)
add-on to simulator.
3 Visual approach monitor (wide-body HUDs).
Vamom Visite d’aptitude à la mise en oeuvre et à la
maintenance (Armée de l’Air, F).
Vamp 1 Variable anamorphic motion picture; see VAM
(2).
2 VHSIC avionics modular processor.
VAMS Vector airspeed measuring system.
Van, VAN 1 Value-added, or visual-area, network.
2 Variable-area nozzle.
3 See next (2).
van 1 Generalized US term for air-conditioned towed
vehicles for major support operations, eg strip, check and
reassemble major avionic systems in field. Not called
trailer.
2 Common term for [usually checkerboard painted]
runway control vehicle, called VAN in code.
vanadium Hard silver-white metal, symbol V, density
6.1, MPt 1,887°C, important alloying element, esp. in
steels.
Van Allen belt(s) Inner and outer zones of high-intensity
particulate radiation trapped in Earth’s magnetic field
around Equator (inner mainly protons, outer mainly
electrons) at radii from Earth’s centre from 8,700 to
26,000 km.
V&A Validation and accreditation.
Van de Graaff Registered name of high-voltage generator
using rotating belt to convey electrical charges.
Vandenberg Originally Camp Cooke, CA, today main
West Coast rocket test base, head of Pacific Missile
Range, address Lompoc (USAF).
Van der Waals equation Best known equation describing
behaviour of real (as distinct from perfect) gas:
(p + a/b 2 )(v – b) = RT, where p is pressure, v volume, R
universal gas constant, T °K and a, b constants.
Van der Waals forces Interatomic or intermolecular
attractive forces between interacting varying dipole
moments; varies as seventh power of radius.
V&F Vinyl and fabric.
V&V Verification and validation (software).
Van Dyke Generalized theory of aerodynamics at Mach
5+ (hypersonics), where air can no longer be assumed
perfect gas owing to molecular vibration, dissociation,
electronic excitation and ionization.
vane 1 Generalized term for thin (flat or, usually, curved
vaporising combustor
but not necessarily aerofoil section) aerodynamic surface
either fixed in order to turn air or gas flow, or freely
pivoted and thus aligning itself with fluid direction.
2 Stator blade of compressor or turbine (orignally US
usage).
3 Gas guide surface at nozzle to turbine (US and UK);
abb. IGV.
4 Strips, usually of circular-arc section, in cascade at
corners of wind tunnel, or used as valves to control flow.
5 Radial strips around fuel burner of gas turbine
imparting rotary vortex motion. Often called swirl *.
6 Curved surfaces in cascade at angle bends of airflow
in many gas turbines; again called swirl * though rotation
is not desired.
7 Curved forward extensions to radial arms of
centrifugal compressor or supercharger impeller, called
rotating guide *, RGV.
8 Alternative (unusual) term for fence.
9 Swinging retractable leading-edge flaps normally
housed in fixed glove of swing-wing aircraft and extended
in high-lift mode, called glove *.
10 Common term for slat fixed to leading edge of flap
and for various other auxiliary aerofoils carried on flaps,
ailerons, droops and leading-edge slats.
11 Normal meaning for weathercocking surface, eg to
indicate angle of attack, or wind direction or relative
wind.
12 Particular application of (1) is sensor in SWIS.
vane passage The airflow channel between two vanes.
vane pump Large family of fluid pumps in which flat
surfaces oscillate and rotate inside chamber eccentrically
arranged around drive shaft.
vane rate Angular velocity of vane in SWIS indicating
rate at which aircraft is approaching stall.
vane set Row of vanes (4) across wind tunnel, either
fixed and profiled to change flow direction or pivoted and
ganged to rotate in unison to control or divert flow.
vanilla aircraft Baseline aircraft on which individual
customer fits are incorporated.
vanity unit Small cabinet housing wash basin, mirror
and [probably] storage.
Vanvis Visual and near-visual intercept system; visual
refers to EM frequency used, not to pilot acquiring target
visually.
Van Zelm Catcher installation for catapult bridles
thrown from aircraft carriers.
VAO Vitrified aluminium oxide.
VAP 1 Vortex avoidance procedure.
2 Visual-Aids Panel (ICAO).
3 Spray dispensing system for HCN or persistent
Toxic-B (USSR).
4 Value-added processor.
V AP See V APP .
VAPI Visual approach-path indicator; also known as
vertical speed and approach-path indicator, suitable for
fixed-wing and helicopter operation.
V apo Velocity at apogee.
vaporiser 1 Heat exchanger which converts Lox into
breathable gas.
2 Alternative name for vaporising combustor.
vaporising combustor Gas-turbine combustion system in
which fuel is vaporised prior to passage through burner
and ignition (usually in walking stick); hence vaporiser, in
which fuel is vaporised, and vaporising burner.
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