investigating AIM-9P(5) Engine Stats

[OpticFlow]

Both the AIM-9P and the AIM-9P5 have incorrect values for engine thrust and time.

In DCS, AIM-9B, AIM-9J and AIM-9JULI all have 2.2 seconds boost stage time and 17 800 newtons thrust. The AIM-9P and AIM-9P5 models also use the same engine (Thiokol Mk.17) and one expects to see the same stats, but instead they have 3 seconds and 18 800 newtons thrust, which is 44% more total impulse.

Correction: The AIM-9P5 uses different engine: Hercules/Aerojet SR.116, but I couldn't find any stats for it.

For reference:

1. Description of the Sidewinder variants:

2. The in-game stats:

• https://github.com/Quaggles/dcs-lua-datamine/blob/master/_G/rockets/AIM-9P.lua

ModelData = { 58, 0.35, 0.04, 0.08, 0.02, 0.05, 1.2, 1.2, 0.5, 0.4, 1.2, 0.29, 0, -1, -1, 3, 0, 0, 0, 1000000000, 0, 0, 8, 0, 0, 0, 0, 0, 0, 18800, 0, 0, 0, 0, 1000000000, 30, 0, 0.5, 1000000000, 1000000000, 0, 30, 0, 1.19, 1, 2, 0, 0, 0, 0, 0, 9000, 4000, 4000, 0.2, 1, 1.4, -3, 0.5 },

• https://github.com/Quaggles/dcs-lua-datamine/blob/master/_G/rockets/AIM-9P5.lua

• https://github.com/Quaggles/dcs-lua-datamine/blob/master/_G/rockets/AIM-9J.lua

ModelData = { 58, 0.35, 0.049, 0.082, 0.01, 0.001, 0.55, 0.8, 2.5, 0.8, 1.2, 0.13, 0, -1, -1, 2.2, 0, 0, 0, 1000000000, 0, 0, 8.45, 0, 0, 0, 0, 0, 0, 17800, 0, 0, 0, 0, 1000000000, 40, 0, 0.8, 1000000000, 1000000000, 0, 30, 0, 1.2, 1, 2, 9, -11, -1.4, 10500, 2800, 17000, 5500, 6700, 2000, 2500, 0.55, -0.01, 0.5 },

The key to read the ModelData parameters:

ModelData = 
	{   58 ,  -- model params count
		0.35 ,   -- characteristic square (характеристическая площадь)
		
		-- параметры зависимости Сx
		0.04 , -- Cx_k0 планка Сx0 на дозвуке ( M << 1)
		0.08 , -- Cx_k1 высота пика волнового кризиса
		0.02 , -- Cx_k2 крутизна фронта на подходе к волновому кризису
		0.05, -- Cx_k3 планка Cx0 на сверхзвуке ( M >> 1)
		1.2 , -- Cx_k4 крутизна спада за волновым кризисом 
		1.2 , -- коэффициент отвала поляры (пропорционально sqrt (M^2-1))
		
		-- параметры зависимости Cy
		0.5 , -- Cy_k0 планка Сy0 на дозвуке ( M << 1)
		0.4	 , -- Cy_k1 планка Cy0 на сверхзвуке ( M >> 1)
		1.2  , -- Cy_k2 крутизна спада(фронта) за волновым кризисом  
		
		0.29 , -- 7 Alfa_max  максимальный балансировачный угол, радианы
		0.0, --угловая скорость создаваймая моментом газовых рулей
		
	-- Engine data. Time, fuel flow, thrust.	
	--	t_statr		t_b		t_accel		t_march		t_inertial		t_break		t_end			-- Stage
		-1.0,		-1.0,	2.2,  		0.0,		0.0,			0.0,		1.0e9,         -- time of stage, sec
		 0.0,		0.0,	8.45,		0.0,		0.0,			0.0,		0.0,           -- fuel flow rate in second, kg/sec(секундный расход массы топлива кг/сек)
		 0.0,		0.0,	17150.0,	0.0,	0.0,			0.0,		0.0,           -- thrust, newtons

 

Edited June 11, 2022 by OpticFlow
Correction for the -P5 engine model.

[NineLine]

Thanks for the report, will look into it. 

[Chizh]

On 6/11/2022 at 10:50 PM, OpticFlow said:

Both the AIM-9P and the AIM-9P5 have incorrect values for engine thrust and time.

In DCS, AIM-9B, AIM-9J and AIM-9JULI all have 2.2 seconds boost stage time and 17 800 newtons thrust. The AIM-9P and AIM-9P5 models also use the same engine (Thiokol Mk.17) and one expects to see the same stats, but instead they have 3 seconds and 18 800 newtons thrust, which is 44% more total impulse.

 

IIRC We use more power SR116 motor for all 9Ps.

Spoiler

https://www.orbitalatk.com/defense-systems/missile-products/sidewinder/

AIM-9P (SR116-HP-1) Sidewinder Propulsion System

The AIM-9 Sidewinder is a supersonic, heat-seeking, air-to-air missile. Used by the U.S. Navy and Air Force, it also has been exported to NATO countries and other U.S allies. It is used by various fixed-wing combat aircraft and helicopters and has been adapted for surface-to-air use as the Chaparral missile. The original IOC for the Sidewinder was introduced in 1956, and many upgrades have been introduced over more than 50 years of service.

The SR116-HP-1 rocket motor is used to power the AIM-9P version of the Sidewinder missile. The AIM-9P Sidewinder was originally introduced in 1978 with upgrades to the target detector and the new, reduced-smoke SR116-HP-1 rocket motor. Later versions of the 9P included additional improvements to the warhead and the guidance/control section. The AIM-9P remains in service in many countries around the world.

The SR116-HP-1 rocket motor was developed by Orbital ATK (formerly Hercules) at the Rocket Center, W.Va., facility. Production began in 1978 and continued until 1990, with more than 30,000 of the "HP" versions of the SR116-HP-1 delivered. SR116-HP-1 rocket motors currently in user inventories are already beyond their designed operational service life.

Orbital ATK received a contract to restart production of the SR116-HP-1 rocket motor in 2012 to extend the useful life of the AIM-9P missile for FMS users. Orbital ATK and RUAG are teamed to provide full-service and upgrade support of the AIM-9P-3/4/5 Sidewinder family of infrared air- to-air missiles.

 

[OpticFlow]

According to some sources, the new engine is used on P2 and later models:

Quote

The AIM-9P-1 has an active optical target detector instead of the infrared influence fuse; the AIM-9P-2 added a reduced-smoke motor. The most recently developed version, the AIM-9P-3, combined both the active optical target detector and the reduced-smoke motor. It also has added mechanical strengthening to the warhead as well as the guidance and control section. The improved warhead uses new explosive material that is less sensitive to high temperature and has a longer shelf life.

https://www.af.mil/About-Us/Fact-Sheets/Display/Article/104557/aim-9-sidewinder/

Quote

The AIM-9P-2 and P-3 were introduced in the mid seventies and use improved guidance electronics, a new rocket motor and an active optical fuse. While not receiving the publicity of the AIM-9L, the success of the weapon is testified to by the fact that no less than 21,000 have been built, with substantial numbers in the USAF inventory.

http://www.ausairpower.net/TE-Sidewinder-94.html

[NineLine]

23 hours ago, OpticFlow said:

According to some sources, the new engine is used on P2 and later models:

https://www.af.mil/About-Us/Fact-Sheets/Display/Article/104557/aim-9-sidewinder/

http://www.ausairpower.net/TE-Sidewinder-94.html

Sadly neither of those sources give enough to model a missile on.