Difference between revisions of "Weapons"

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(External ballistics)
(Simplifications)
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=== Simplifications ===
 
=== Simplifications ===
 
* Due to simplifications of ballistics calculations, minor forces (like Gyroscopic drift, Magnus effect, Poisson effect etc.) not taken into account
 
* Due to simplifications of ballistics calculations, minor forces (like Gyroscopic drift, Magnus effect, Poisson effect etc.) not taken into account
* Because of absent of air temperature, pressure and humidity real time calculations, normal values of ground level are used
+
* Because of absence of air temperature, pressure and humidity real time calculations, normal values of ground level are used
 
* Missiles and rockets lift does not affect drag force anyhow, but it can be compensate by changing Drag coefficient modifier of the weapon
 
* Missiles and rockets lift does not affect drag force anyhow, but it can be compensate by changing Drag coefficient modifier of the weapon
 
* Wind does not affect projectiles launched by AI for practical reasons
 
* Wind does not affect projectiles launched by AI for practical reasons

Revision as of 19:31, 2 May 2014

Weapon types

Rockets and missiles Projectiles
Rockets and missiles has solid fuel motor that creates thrust. There is three types of rocket motors: all-boost, all-sustain and boost-sustain Projectiles has no any power sources and use only kinetic energy to move to target position
All-boost All-sustain Boost-sustain Shell Shot
All-boost motor burns out in short period of time and gives to rocket high peak velocity. It suitable for short-range missiles and rockets, because higher velocity causes higher drag forces
Sidewinder.gif
All-sustain motors gives less acceleration, but works much longer. It's suitable for guided missiles with high rate of turn, because it makes possible to provide stable maneuvering on all given range
Archer.gif
Boost-sustain combine two types in one - at first stage motor give to rocket high acceleration, after peak velocity reached thrust power decreased and holding current velocity level
Karen.gif
Shell is a payload-carrying projectile which contains an explosive or other filling. Depending on the type of fuse used the shell can be set to burst on the ground (percussion) or in the air above the ground (time or proximity)
Cannon shell.jpg
Shot is solid projectile without explosive charge, may contain a pyrotechnic compound if a tracer or spotting charge is used
Cannon shot.jpg

Warhead types

Solid shot High explosive anti-tank High explosive dual purpose High explosive High explosive anti-aircraft Conventional munition
Solid projectile without explosive charge. It loses damage and penetration capabilities with range. HEAT warhead was designed to use it against heavy-armored vehicles. HEAT has explosive shaped charge that uses the Munroe effect to create a very high-velocity partial stream of metal in a state of superplasticity that can punch through solid armor. Also some warheads has tandem charge to be more effective against reactive or multilayered armor. Side effect of high armor penetration - low fragmentation and it's blast can cause only minor damage to close unarmored targets
HEAT.gif
HEDP is variation on HEAT warheads that surrounding them with a conventional fragmentation casing, to allow the warhead to be more effectively used for blast and fragmentation attacks on unarmored targets.
HEDP.gif
HE charge is used to disintegrate the target, and damage surrounding areas with a blast wave and large quantity of metal fragments accelerates to a high velocity.
HE.gif
HE anti-aircraft is HE warhead with time, proximity or remote fuse. It can be used against aircrafts and missiles to cause damage without direct hit.
HEAA.gif
Conventional weapons include small arms and light weapons, sea and land mines, as well as (non-nuclear) bombs, shells, rockets, missiles, and cluster munitions. Sub-munitions are ejected at an optimum altitude and distance from the desired target for dense area coverage.
M261.gif
  • Explosion damage radius is square root of damage capability value, meters.

External ballistics

When in flight, the main forces acting on the projectile are gravity, drag, and if present, wind. Gravity imparts a downward acceleration on the projectile, causing it to drop from the line of sight. Drag, or the air resistance, decelerates the projectile with a force proportional to the square of the velocity. Wind makes the projectile deviate from its trajectory. During flight, gravity, drag, and wind have a major impact on the path of the projectile, and must be accounted for when predicting how the projectile will travel.

Simplifications

  • Due to simplifications of ballistics calculations, minor forces (like Gyroscopic drift, Magnus effect, Poisson effect etc.) not taken into account
  • Because of absence of air temperature, pressure and humidity real time calculations, normal values of ground level are used
  • Missiles and rockets lift does not affect drag force anyhow, but it can be compensate by changing Drag coefficient modifier of the weapon
  • Wind does not affect projectiles launched by AI for practical reasons
  • For all weapons used same Drag coefficient (air resistance law of 1943)

Forces

Ballistics gravity.jpg
Ballistics drag force.jpg
Ballistics drag coefficient.jpg
Ballistics wind.jpg

Gravity

Gravity force affect all projectiles and rockets except guided missiles that has active target and enough velocity to provide enough lift. Gravity is constant force that create negative vertical acceleration 9.81m/s whatever position/attitude projectile or rocket has.

Drag force

Aerodynamic drag force on a bullet is a function of the air density through which the bullet flies, the axial cross-sectional area of the bullet upon which the drag acts, the velocity of the bullet, and the speed of sound.

Base function to determinate drag force is:

D = 0.5 * Cd * Cdw * r * v^2 * A

  • Cd drag coefficient, table value depends on current velocity
  • Cdw drag coefficient modifier of the weapon
  • r air density, kg/m^3
  • v current weapon velocity, m/s
  • A frontal area, m^2
r = p * M / (R * T) A = PI * D^2 / 4
  • p absolute air pressure, Pa
  • M molar mass (0.0289644)
  • R ideal gas constant (8.31447)
  • T absolute air temperature, K
  • D diameter (caliber), m
p = p0 * exp(- (G * M * H) / (R * T0))
  • H current weapon altitude, m
  • T0 standard sea level temperature (288.15K)
T = T0 - 0.0065 * H

Deceleration caused by drag force:

a = D / m

  • m current projectile or rocket weight, kg

Wind

Wind create force similar to drag force. Only difference - wind velocity and direction using to calculate acceleration, given to weapon by wind.

Official names

  • XM-301 "Chain Gun"
  • AIM-92 "Stinger"
  • AGM-114 "Hellfire"
    • Variant AGM-114K is laser guided.
    • Variant AGM-114L is radar guided.
  • Hydra 70 "Hydra Rockets"
    • Variant M255 has a high explosive (HE) warhead.
    • Variant M261 has a multiple purpose sub munition (MPSM) warhead.

Weapons

Chain Gun

Range: 1 km
Speed: 1030 meters per second
Guidance: none
Comments: Depending on target type, ground or air, firing rates are 750 respectivily 1,500 shots per minute.
More information:

Stinger

Stinger.jpg Range: 5 km
Speed: Mach 2.2
Guidance: Infra Red (IR)
Primary target: air threats: helicopters, fighters
Tactics:
  • There is a high rate for a Stinger to get spoofed [by flares]. Cargo aircraft carries lot's of flares, making this missile completely useless against these targets.
  • Stingers are the most wastable missiles to have. Do not preserve them too much. Launched by double/triples increases its success.
  • Stinger are most effective at close range (< 2km).
  • Enemy fighters fly at high speed. Hellfires can’t keep up, stingers can.
  • It’s limited range (5 km) is a serious draw back. Most fighters are out of range and stay out of range.
Comments:
More information:

Hellfire

Hellfire.jpg Range: 8 km
Speed: Mach 1,3
Guidance: Active radar (RF) or Laser (Lsr)
Tactics:
  • The hellfire is the ultimate anti-tank missile. It has a warhead for small and heavy armoured targets.
  • Anti-aircraft artillery can return fire immediately with faster missiles and are able to get the first hit!
  • The missile has a lock on after launch mode, which is very useful to engage behind cover.
  • The laser Hellfire is very useful against freight planes and helicopters, it can't be spoofed by countermeasures, a hit is almost certain.
Comments:
  • The laser Hellfire requires constant painting in order to get a it.
  • The radar Hellfire is fire and forget.
More information:

Rockets

Rockets.jpg Range: infinite
Speed: Mach 1.9
Guidance: unguided
Primary target:
  • long range: surface targets
  • close range: soft ground targets
Accuracy: 75 m radius at 2000m.
Tactics:
  • Rockets are designed as "areal artillery", to suppress ground surfaces from a distance.
  • Pick off soft targets at close range will also work when there's no SAM nearby.
Comments:
  • M255 high explosive (HE) contain flechettes and a big boom, intended as anti-personnel weapon.
  • M261 multiple purpose sub munition (MPSM) contains sub munition intended to hit (soft armoured) surface targets.
More information:

2A42

Range: 2 km
Speed: 1000 metres per second
Guidance: none
Comments: A singe barrelled 30 mm 2A42 cannon.

Vikhr-M

Range: 6 km
Speed: Mach 1,1
Guidance: Laser
Comments:

Igla-V

Range: 5,2 km
Speed: Mach 2,5
Guidance: Infra red homing
Comments: Fire and forget

S-8

Range: 4 km
Speed: fast
Guidance: none
Comments:

S-13

Range: 6 km
Speed: fast
Guidance: none
Comments:

UPK-23

Range: 2 km
Speed: 930 meters per second
Guidance: none
Comments: Twin barrelled GSh-23L.

Load out

helicopter weapon load out
inner outer wingtips total
Comanche Hellfire 8 6 0 14
Stingers 12 16 0 28
Hydra 0 38 0 38
Apache Hellfire 8 8 0 16
Stingers 16 16 4 36
Hydra 38 38 0 72
Hokum Vikhr 0 12 0 12
Igla 4 4 0 8
S-8 40 40 0 80
S-13 10 10 0 20
UPK-23  ?  ? 0  ?
Havoc Vikhr  ?  ?  ?  ?
Igla  ?  ?  ?  ?

See also

  • More info about weapons can be found in the game manual.
    Manual > Enemy Engaged - Comanche Havoc > Chapter 4.30 "Weapons".

External links