[FAR]PitchGreat K-31, a plane for Ferram Aerospace Research

[localSol]

This is the 'Pitchgreat K-31' based on the Rockwell X-31 experimental thrust vectoring jet from the 90's that I only heard of this week. I named mine because it pitches great, and you could say it rocks well, if to rock is to pitch! [Pun emoticon?] I only guessed at the vectoring and used a miniature B9 f119 with 30 degree thrust vectoring and extra small pseudo-canards from scaled av-r8 winglets, guessing at FAR aerodynamic values for its config. Is it true that the X-31 didn't use elevators? In any case I set the ones I put on it as flaps only to test flight with only the canards and engine, which worked fairly well especially at subsonic speed and low altitude. No idea how the rockwell's engine works other than its three paddles, but I wondered if using a group of 3 tiny(er) f119 engines arranged similarly might simulate it better for another version?

Of course this uses the very excellent Procedural Wing mod - the mod that lets you stretch and shape wings with the mouse, so you can do things that would be impossible otherwise, either for looks or for aerodynamics with FAR.

(Click gear to watch in 720p)

http://www.youtube.com/watch?v=WwRihkhhMx4

engine cfg for modulemanager as 'smallf119.cfg' in 'GameData\B9_Aerospace\Parts\Engine_Jet_Turbofan_F119' :

PART
{
    // --- general parameters ---
    name = B9_Engine_Jet_Turbofan_F119_S_Sub
    module = Part
    author = bac9

    // --- asset parameters ---
    mesh = model.mu
    scale = 1.0
    rescaleFactor = 0.5

    // --- node definitions ---
    node_stack_top = 0.0, 0.5, 0.0, 0.0, 1.0, 0.0, 0

    // --- FX definitions ---
    fx_exhaustLight_yellow = 0.0, 0.0, 0.0, 0.0, 0.0, 1.0, power
    fx_smokeTrail_light  = 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, power
    fx_exhaustSparks_flameout = 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, flameout

    // --- Sound FX definition ---
    sound_vent_medium = engage
    sound_jet_low = running
    sound_jet_deep = power
    sound_vent_soft = disengage
    sound_explosion_low = flameout

    // --- editor parameters ---
    TechRequired = aerospaceTech
    entryCost = 19450
    cost = 2200
    category = Propulsion
    subcategory = 0
    title = F119 Turbofan Engine Small Subsonic Fan
    manufacturer = Tetragon Projects
    description = State-of-art  afterburning low-bypass turbofan engine capable of sustained supercruise speeds. Fitted with latest in thrust vectoring technology, this engine provides extreme pitch authority, and, if multiple engines are present, outstanding roll authority. Obvious choice whenever superior maneuverability is desired.

    // attachment rules: stack, srfAttach, allowStack, allowSrfAttach, allowCollision
    attachRules = 1,0,1,0,0

    // --- standard part parameters ---
    mass = 0.255
    dragModelType = default
    maximum_drag = 0.2
    minimum_drag = 0.2
    angularDrag = 2
    crashTolerance = 7
    breakingForce = 75
    breakingTorque = 75
    maxTemp = 3600

    MODULE
    {
        name = ModuleEngines
        thrustVectorTransformName = thrust_transform
        exhaustDamage = False
        ignitionThreshold = 0.1
        minThrust = 0
        maxThrust = 45
        heatProduction = 600
        useEngineResponseTime = True
        engineAccelerationSpeed = 1.3
        engineDecelerationSpeed = 2.0
        useVelocityCurve = True
        fxOffset = 0, 0, 1.8
        PROPELLANT
        {
            name = LiquidFuel
            ratio = 1
            DrawGauge = True
        }
        PROPELLANT
        {
            name = IntakeAir
            ratio = 45
        }
        atmosphereCurve
        {
            // Based on Isp/TSFC data from NASA EngineSim, and Kerbin atmo.
            key = 0       1731 0   -8600000
            key = 7.5E-06 1675 0   0
            key = 0.0006  1781 0   0
            key = 0.11    1715 0   0
            key = 1       1800 120 0
        }
        velocityCurve
        {
            // Based on Fnet data from NASA EngineSim, curve fitted with MuMech CurveEd
            key = 0   1    0     -0.002
            key = 500 0.67 0     0
            key = 550 0.44 -0.01 -0.01
            key = 605 0    0     0
        }
    }

    MODULE
    {
        name = ModuleAnimateHeat
        ThermalAnim = jet_engine_f119_heat
    }

    MODULE
    {
        name = ModuleAlternator
        RESOURCE
        {
            name = ElectricCharge
            rate = 5.0
        }
    }

    MODULE
    {
        name = SmarterGimbal
        gimbalTransformName = thrust_transform
        pitchRange = 30
        useGimbalResponseSpeed = true
        gimbalResponseSpeed = 60
    }

    RESOURCE
    {
        name = ElectricCharge
        amount = 0
        maxAmount = 0
    }

    MODULE
    {
        name = FXModuleConstrainPosition
        matchRotation = true
        matchPosition = false
        CONSTRAINFX
        {
            targetName = lookatfx_target1
            moversName = plate1_holder
        }

        CONSTRAINFX
        {
            targetName = lookatfx_target2
            moversName = plate2_holder
        }
    }
}

relevant av-r8 mod for use with modulemanager (an-add on to TV-PP.cfg [or another cfg] in 'GameData\Squad\Parts\Aero\winglet2' :

PART
{
// --- general parameters ---
name = R8wingletES
module = ControlSurface
author = NovaSilisko

// --- asset parameters ---
mesh = model.mu
scale = 0.1
rescaleFactor = 0.625


// --- editor parameters ---
TechRequired = flightControl
entryCost = 500
cost = 200
category = Aero
subcategory = 0
title = AV-R8 Winglet Extra Small(ES)
manufacturer = Kerlington Model Rockets and Paper Products Inc.
description = The R8 Active Control Winglet series marked the debut of Kerlington Model Rockets in the Spacecraft engineering world. These winglets are equipped with movable pivots, which allow them to swivel and act as control surfaces. This feature was considered a huge advancement in control technology and most agree that it made Kerlington staff and R8 fans simply unbearable to be around.
// attachment rules: stack, srfAttach, allowStack, allowSrfAttach, allowCollision
attachRules = 0,1,0,1,1

// --- node definitions ---
// definition format is Position X, Position Y, Position Z, Up X, Up Y, Up Z
node_attach = 4.32401, 1.39785, 0.0, 1.0, 0.0, 0.0


// --- standard part parameters ---
mass = 0.008
dragModelType = override
maximum_drag = 0.01
minimum_drag = 0.01
angularDrag = 5
crashTolerance = 12
breakingTorque = 50
breakingForce = 50
maxTemp = 3400
explosionPotential = 0.1

// --- winglet parameters ---
// dragCoeff will override the maximum_drag value
dragCoeff = 0.77
deflectionLiftCoeff = 0.16
ctrlSurfaceRange = 15
ctrlSurfaceArea = 0.95

   MODULE
    {
        name = FARControllableSurface
        MAC = 0.85
        e = 0.75
        IsSmallCtrlSurf = 0
        MidChordSweep = 27.6
        maxdeflect = 15
        b_2 = 0.75
        TaperRatio = 0.611
    }
// --- tweakables (coming soon...) ---




// ----- DO NOT EDIT BELOW THIS POINT ------

}

More technical stuff : It's a subsonic plane using no pitch control surfaces in the video other than the tiny canards on the front, modded by scaling an r8 winglet down and guessing for aerodynamic values based on ferram and taverius's settings for larger r8 winglets. The engine is a scaled down B9 f119 turbofan with 30 degree vectoring added (normally 20 degree) and using mostly taverius's turbofan(not turbojet) engine settings for rapid subsonic thrust.

In the video I turned off gyro force in the pod, and I'm demonstrating the plane's ability for short takeoff, air-stunt ability and the plane's reliance on thrust for pitch control at (relatively) high subsonic speed. I think a real X-31 is around 5.5 to 7 thousand kilograms. The K-31 has similar but different fuselage proportions because I'm not an artist and wanted a functional plane quickly. I'm using Modular Fuels with realfuels and some N2O4 as ballast (increase weight/mass). It is about 3.5 to 3.8 thousand kilograms but has less thrust than an X-31, at about 30 to 45 kilonewtons with no afterburner installed, where the X-31 is supposed to have up to ~71kN with afterburner. Romfarer's lazor system mod would make an afterburner possible with a few parts. Todo : add afterburner to break mach to around 1.28 like the real X-31, experiment with weird-funner thrust vectoring..

A NASA page on the X-31 : http://www.nasa.gov/centers/dryden/news/FactSheets/FS-009-DFRC_prt.htm

Wiki's page on the X-31 : http://en.wikipedia.org/wiki/Rockwell-MBB_X-31

Edited December 15, 2013 by localSol