Aerodynamics model for Kerbal Space Program

Serious thanks: * a.g., for tons of bugfixes and code-refactorings
* stupid_chris, for the RealChuteLite implementation * Taverius, for correcting a ton of incorrect values
* Tetryds, for finding lots of bugs and issues and not letting me get away with them, and work on example crafts * sarbian, for refactoring code for working with MechJeb, and the Module Manager updates
* ialdabaoth (who is awesome), who originally created Module Manager
* Regex, for adding RPM support
* DaMichel, for some ferramGraph updates and some control surface-related features
* Duxwing, for copy editing the readme

CompatibilityChecker by Majiir, BSD 2-clause http://opensource.org/licenses/BSD-2-Clause

Part.cfg changes powered by sarbian & ialdabaoth's ModuleManager plugin; used with permission
http://forum.kerbalspaceprogram.com/threads/55219

ModularFLightIntegrator by Sarbian, Starwaster and Ferram4, MIT: http://opensource.org/licenses/MIT http://forum.kerbalspaceprogram.com/threads/118088

Toolbar integration powered by blizzy78's Toolbar plugin; used with permission
http://forum.kerbalspaceprogram.com/threads/60863

Source available at: https://github.com/ferram4/Ferram-Aerospace-Research

Install by merging the GameData folder in the zip with the GameData folder in your KSP install

ModuleManager and ModularFlightIntegrator are REQUIRED for FAR to work properly. Failing to copy this over will result in strange errors.

Sample Part.cfg:

MODULE  
{  
	name = FARControllableSurface / FARWingAerodynamicModel  
	b_2 = 0.5				//distance from wing root to tip; semi-span  
	MAC = 0.5				//Mean Aerodynamic Chord  
	nonSideAttach = 0			//0 for canard-like / normal wing pieces, 1 for ctrlsurfaces attached to the back of other wing parts  
	TaperRatio = 0.7			//Ratio of tip chord to root chord generally < 1, must be > 0  
	MidChordSweep = 25			//Sweep angle in degrees; measured down the center of the span / midchord position  
	maxdeflect = 15				//Default maximum deflection value; only used by FARControlableSurface  
	controlSurfacePivot = 1, 0, 0;		//Local vector that obj_ctrlSrf pivots about; defaults to 1, 0, 0 (right)  
	ctrlSurfFrac = 0.2			//Value from 0-1, percentage of the part that is a flap; only used by FARControlableSurface  
}

For control surfaces, use above but replace FARWingAerodynamicModel with FARControllableSurface and add maxdeflect value

Set all the other winglet/control surface values to zero

0.15.5.3V "von Helmholtz"------------------------------------

Upgrade to MM 2.6.13

RealChuteLite consistency with RealChute calcs and optimizations thanks to stupid_chris
Implement dynamic smoothing calculations based on relative "filledness" of voxel; should help reduce effect of voxel-resolution-induced smoothing on larger vehicles
Tweaks to critical Mach calculations

Fix "silent" KSP update breaking hydrodynamic drag
Fix some voxelization irregularities
Fix control surface flap settings not appearing if the settings are turned on in flight
Fix some other control surface in-flight changes oddities

Fix Firehound MS example craft action groups not acting in symmetry
Added E42 example craft by tetryds

0.15.5.2V "Helmbold"------------------------------------

Compatibility with KSP 1.0.5
Upgrade to MFI 1.1.2

Optimizations of runtime aerodynamic calculations
Cut background memory usage for voxels to ~60% of previous value
Increases in consistency of properties with similar voxel shapes

Full support for new stock hydrodynamic drag
Voxel model used in calculating radiative influx from celestial bodies
Reduction in first-load inconsistency in editor
More varied support for intake ducting setups, including support for stock Goliath engine
Tweaks to intake drag at low airbreather throttles

Editor GUI header cleanup
Dropdowns notated with down triangles for clarity
Added AoA Arrow to make AoAs for static analysis sweeps and stability deriv sims clearer

Fix for voxelization issues with degenerate triangles
Fix for voxelization issues with meshes with 0 triangles
Fix for B9 pWings not solidifying properly
Fix editor race condition in displaying sonic drag for vehicles
Fix for multiple vehicle aerodynamic NREs that could break aero
Fix for vehicle aerodynamics breaking under certain vessel-part configurations

Updated FAR Firehound MS, FAR SkyEye, FAR Montauk Shuttle to be more useful in KSP 1.0.5

0.15.5.1V "Hayes"------------------------------------

Upgrade to MM 2.6.8

Fix some legacy wing interaction issues
Fix drag properties drifting slowly over multiple voxelization events due to numerical errors
Fix parts being occluded when main axis is in a strange orientation
Fix in-flight control surface tweaks not applying to symmetry counterparts
Fix KerbalEVAs working with Vanguard Parachutes

Fix for a critical error where detached boosters, weapons, debris, etc. would not have drag properties

0.15.5V "Haack"------------------------------------

Upgrade to MM 2.6.7
Fix for some RealChute issues by DaMichel
Animation ignoring for voxelization by Blowfish
Addition of air brakes for yaw control (RudderBrakes) adopted from original code contributed by HoneyFox

Reduction in memory garbage created during voxelization; this should reduce the impact of voxelization somewhat, especially hitching. Note: some hitching may still occur with vehicles with many wing parts due to legacy wing code
Runtime performance optimizations for ram drag and general aero calculations
Highly optimized bounds checking for voxelization

Kerbals handled by voxel model now (using a simple primitive shape, presence or absence of helmet doesn't matter)
Control surface parameters available for tweaking in flight
Control surface tweakables given open/close buttons for sections to reduce clutter
Revert BDArmory bombs and missiles to stock model after launch to improve tracking, stability and predictions

Fixed main axis issue with BDArmory parts and similarly designed parts
Fixed a long-standing issue in wing aspect ratio calcs (they were double what they should have been)
Fixed ram drag variation with throttle not accepting AJE jets as valid jets for that purpose
Fixed drag not using the calculated critical Mach number for the beginning of the drag transonic rise
Fixed possible NRE issues during steady destruction of vessel with parts being destroyed
Fixed issue where increased number of wing parts would cause wing mass adjustment to increase mass without bound; mass is now bounded, but more concentrated in root parts than wingtip parts

Tweaked subsonic drag downwards to get more accurate results with fixed AJE props Tweaked wing mass downwards slightly
Tweaked wing strength power to result in greater strength from lower-mass wings

0.15.4.1V "Goldstein"------------------------------------

Re-implementation of aero viz coloration, thanks to mjn33

Reduction in garbage produced by voxelization, prep for further garbage reductions

Fixed NaN issue with KAX electric props
Fixed drag-breaking NRE during rapid disintegrations
Fixed some issues with Blizzy Toolbar icons
Fixed exacerbation of stock heating bug
Fixed control surfaces not updating direction during staging-related CoM shifts

0.15.4V "Glauert"------------------------------------

Update to MM 2.6.6
Update to MFI 1.1.1, fixes gimbaling bug below 750 m/s on short vehicles
Update win64 check code to MM method

Added internal ducted area feature:
* Area ducted through a vehicle from intakes to airbreathing engines will be removed from cross-section
* Adjusts area ruling to properly model air that flows through the vehicle as opposed to around it
* Does not count for airflow through switch-backing or reversing ducts; no benefits for intakes that feed upstream engines
* Supports stock intake part + airbreathing engine part setups, AJE intake part + airbreathing engine part setups, and combined intake + engine part setups

Slight improvement to Flight Data readouts from mjn33
Toggle gear button now states "Raise" or "Lower" gear for clarity

Fixed serious issue where exposed area was not updated for thermal calculations
Fixed some blunt shapes having NaN drag in the transonic regime
Fixed some blunt, thin-plate shapes having negative drag in the transonic regime
Fixed serious issue where long, skinny vehicles would have incorrect 2nd derivatives and incorrect transonic drag as a result
Fixed NRE with Launch Clamps
Fixed NRE with animations that are removed from a part (for whatever reason)

Cleaned up unused values from FARAeroData.cfg
Added support for planets to be identified by planet name, not just index; combining these in a FARAeroData MM patch is likely to cause overwrites, don't do it
Added ability to read and set flap and spoiler states from FARAPI
Fixed Firespitter gear not responding to Toggle Gear button
Added support for adjustable landing gear in Toggle Gear button
Stopgap fix to unintended voxelization of USI Warp Drive bubbles

0.15.3.1V "Garabedian"------------------------------------

Compatibility with KSP v1.0.3 and thermal changes
Fix one last error with voxelization breaking due to reverts

Add ability to make parts not count for main axis determination; fix structural panels interfering with proper main axis determination

0.15.3V "Froude"------------------------------------

Update to MM 2.6.5 for greater nyan nyan
Allow display of pressure coefficient (under assumption of axisymmetric flow) over the vehicle
Tweak subsonic drag to be lower for slender shapes

Fixed voxelization breaking due to combined memory leak + hard memory limit for voxelization after many editor -> flight cycles
Fixed some race conditions in voxelization that could break aero properties
Fixed deadlock in threadpool if many voxelization events triggered simultaneously
Fixed possibility of deadlock if voxelization settings were updated

Fixed voxelization errors for some cargo bays and other parts
Fixed voxelization errors for pWings; includes support for any parts making use of mirrorAxis

Fixed some longstanding wing interaction issues, including permanent stalled wings
Fixed a newer issue with wing shielding on symmetry counterparts

Some main axis determination improvements
Fixed an where certain user atmospheric settings would not take

0.15.2V "Ferri"------------------------------------

Improved voxelization accuracy
Changed CoL code again to try and make it more useful
Cleaned up some unnecessary calculations

Fixed voxelization breaking after many voxelization events; this fixes no-drag situations
Fixed deployed spoilers not producing drag if mounted flush with vehicle
Fixed some main axis issues
Fixed improper heating area for atmospheric heat

Fixed interaction with KIS breaking things
Fixed some data not saving
Fixed exceptions during EVA

0.15.1V "Fanno"------------------------------------

Fixed improper voxelization of debris and vehicles dropped from existing vessel, including effects on stock "occlusion" system
Fixed improper determination of vehicle main axis
Fixed Kerbal EVAs having no drag
Fixed exceptions where outirght disintegration could prevent some vehicles from having aerodynamics applied

Added upper cap on memory allocated for voxelization

Changed calculation of CoL to make more sense
Fixed error in determining AoA for nominal flight in Stability Derivative GUI
Hid yellow aero moment arrows by default in aero overlay to reduce user confusion
Fixed lift / drag arrows remaining on wings that become shielded when aero overlay is open

Switched to a cleaner method of setting internal speedometers
Disable control surfaces auto-response below 5 m/s to prevent wacky flailing during load / when stopped

Change compatibility settings to reject KSP 1.0.0, which is not compatible with RealChuteLite
Updated save-load method to save more reliably and not throw exceptions

0.15V "Euler"------------------------------------

Compatibility with KSP 1.0, 1.0.1, and 1.0.2
Upgraded to MM 2.6.3
Introduction of ModularFlightIntegrator for interfacing with KSP drag / heating systems without interference with other mods

Replaced previous part-based drag model with new vessel-centered, voxel-powered model:
* Generates voxel model of vehicle using part meshes, accounting for part clipping
* Drag is calculated for vehicle as a whole, rather than linear combination of parts
* Payload fairings and cargo bays are emergent from code and do not require special treatment with configs
* Area ruling of vehicles is accounted for; unsmooth area distributions will result in very high drag at and above Mach 1
* Body lift accounts for vehicle shape in determining potential and viscous flow contributions
* Areas exposed to outside used for stock heating calculations

Performance optimizations in legacy wing model
Jet engine windmilling drag accounted for at intakes

Editor GUI improvements including:
* Greater clarity in AoA / Mach sweep tab
* Stability deriv GUI math modified for improved accuracy
* Stability deriv simulation tweaked to fix some minor issues in displaying and calculating response
* Addition of a Transonic Design tab that displays cross-section distribution and drag at Mach 1 for area ruling purposes

Parachute methods have been replaced with RealChuteLite implementation by stupid_chris:
* Less severe parachute deployment
* Parachutes melt / break in high Mach number flows
* No interference with RealChute

Changes to FARAPI to get information faster

FARBasicDragModel, FARPayloadFairingModule, FARCargoBayModule are now obsolete and removed from the codebase
Extensive reorganizing of source to reduce spaghetti and improve maintainability

Modifications to Firehound and Colibri to function with new flight model
Addition of Blitzableiter and SkyEye example crafts

A 1.5x increase to all stock gimbal ranges

0.14.7V------------------------------------
Features:
Raised stalled-wing drag up to proper maximum levels
Adjusted intake drag to be lower
Improved method of dealing with very high vertex count parts for geometry purposes
Upgraded to MM 2.5.13
Included FAR Colibri, a VTOL by Tetryds as an example craft

Bugfixes:
Fixed an issue preventing loading custom-defined FARBasicDragModels

0.14.7V------------------------------------
Features:
Raised stalled-wing drag up to proper maximum levels
Adjusted intake drag to be lower
Improved method of dealing with very high vertex count parts for geometry purposes
Upgraded to MM 2.5.13
Included FAR Colibri, a VTOL by Tetryds as an example craft

Bugfixes:
Fixed an issue preventing loading custom-defined FARBasicDragModels

0.14.6V------------------------------------
Features:
Modified skin friction variation with M and Re to closer to that expected by using the Knudsen number
Changed saving and loading method to allow better behavior when settings need to be cleaned during updates, especially for automated installs
Modified aerodynamic failures for water landings for compatibility with upcoming BetterBuoyancy
Option for aerodynamic failures to result in explosions at the joint during failure.
Serious reworking to handle edge cases with lightly-clipped parts and their effects on blunt body drag (read: when people clip heatshields into the bottom of Mk1 pods and cause problems)
Upgrade to MM 2.5.6

Bugfixes:
Fixed an issue that prevented Trajectories from functioning
Fixed blunt body drag errors with AJE
Fixed issues involving editor GUI and control surface deflections
Fixed edge cases involving attach-node blunt body drag being applied when it shouldn't have
Fixed issues with command pods containing intakes

0.14.5.1V------------------------------------
Features:
Add Reynolds Number readout to main flight GUI

Tweaks:
Adjust skin friction drag for rarefied atmosphere

Bugfixes:
Fix Stab Deriv GUI from breaking for altitudes above atmosphere
Fix flaps and spoilers not functioning with negative deflections

0.14.5V------------------------------------
Features:
Skin friction drag now varies with Reynolds number; this means much higher skin friction drags at higher altitudes
Added simple attempt at handling hydrodynamic effects; not detailed, but objects in oceans move much less
Added color changing options for colorblind users
Tweak flap and spoiler deflection functions
Give spoilers faster deflection coefficients
Update to ModuleManager 2.5.4

Bugfixes:
Removed spontaneous aero-spline warp drive in some Linux64 versions

0.14.4.1v------------------------------------
Features:
Added changes to blunt body drag to make command pods more stable on reentry
Attempt to account for most inaccurate effects of part clipping

0.14.4v------------------------------------ Features:
Default ActionGroups now controlled throuhg dropdown menus rather than string entry
Stability Deriv tab now takes entry in terms of planet, altitude and Mach Number, not density, temperature and Mach number
Stability Deriv tab now accounts for reduced gravity due to high speeds

Contributed by HoneyFox:
Pitch damper now has an additional gain for greater tuning
Control surfaces can now be set to deflect in response to local AoA changes
Control surfaces are not On/Off for a given control direction; can be scaled from -100% to 100% for each

Contributed by Bitronic:
Full Tweakscale Support

BugFixes:
Fixed no shielding with some payload fairings (particularly resized procedural fairings)
Fixed aero tinting blocking tinting from other mods

0.14.3.2v------------------------------------
Features:
Contributed by Da Michel:
Airspeed settings change readouts in cockpits

Bugfixes:
Fixed serious issues with the wing interaction code
Fixed an issue where wind velocity was applied in the opposite direction that was expected

0.14.3.1v------------------------------------
Features:
Improved performance in editor and flight for vessel configuration changes
Fliht GUI appears in mapview

Bugfixes:
Fixed neverending stall resulting from wing interactions with sudden changes in velocity vector direction
Fixed flight GUI issues when passing another vehicle

0.14.3v------------------------------------ Features: Refactored wing interaction code:
Wing interactions should be smoother
Code should be less processor intensive

Upgrade to ModuleManager v2.5.1
Added stall visualization to aero force visualization
Added ability to scale wing mass up or down for additional strength / weight savings (addedby NathanKell)
Improved cargo bay and payload fairing detection algorithm

Tweaks:
Reduced intake drag
Decreased wing mass per area slightly

Bugfixes: Fixed aero visualization leaving parachutes glowing brightly
Fixed some critical errors for when config files do not have values listed
Fixed an issue with AppLauncher buttons multiplying when KSP fails at loading a particular vessel

0.14.2v------------------------------------ Features: 0.25 compatibility, with stock support for SP+ parts
Upgrade CompatibilityChecker
Disable functions on CompatibilityChecker warnings

Prototype aero force visualization in flight
Removed vector from CoL indicator to reduce confusion
More Get functions for the FARAPI
Estimated range and endurance readouts in the Flight Data UI
See and dump FAR module data in the VAB / SPH using the Editor GUI
Some runtime optimizations

Contributed by Da Michel:
Implement separate deflection speeds for flaps / spoilers
Allow preferred default action groups for spoilers / flaps
Contributed by regex:
Add some RPM integration
Contributed by Ippo:
FARWind class for 3rd-party wind implementation

Bugfixes: Fixed some vessel-switching FAR GUI issues
Fixed control surface reversal on undocking or backwards root part selection
Fixed some issues involving CoL position with wings when dealing with parts that have multiple colliders
Fixed some payload fairing and cargo bay part detection issues