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Config Variable Definitions
These are the variables that can be set to define the performance of an engine in AJE. Since AJE uses a solver to calculate engine performance based on the given inputs, what you put in the configs may not be what you get in game! Just adjust your inputs until the in game values match your desired values. This information was mostly gained by trial and error and reading the source code, so may not be completely accurate.
This is the area of the jet engine compressor. It is primarily used to determine how much intake area the engine requires, but is also used to determine how quickly the engine spools, and to help fit the engine performance solver. Default value = 0.1 (m^2)
This is the bypass ratio, or the ratio of inlet air that bypasses the engine core over the air that enters the engine core. It is only applicable to turbofans, and should be set to 0 for turbojets. default value = 0 (unitless)
This is the compressor pressure ratio, or how much air is compressed in the engine's compressor stage. This is one of the most important properties of an engine, and will have a large effect on how the engine performs. Due to the calculations performed by the engine solver, there may be a small difference between what you set, and what you see in game. Just adjust to compensate until the value you see in game matches your desired value. default value = 20 (unitless)
This is the fan pressure ratio, or how much air is compressed in the engine's fan. This is only applicable to turbofan engines, and should be left at 1 for turbojets default value = 1 (unitless)
This is the Mach design point. It is used to help fit the engine solver to give more accurate engine performance, but will not directly effect the engine. default value = 0.9 (Mach)
This is the temperature design point. It is used to help fit the engine solver to give more accurate engine performance, but will not directly effect the engine. default value = 250 (Kelvin)
Conditions at compressor exit/burner inlet, or compressor efficiency. This determines how much work and heat is generated by the engine compressor stage. default value = 0.95 (unitless)
Conditions at burner exit/turbine inlet, or turbine efficiency. This determines how much work and heat is extracted by the engine turbine stage. default value = 0.98 (unitless)
Conditions at afterburner exit/nozzle inlet, or nozzle efficiency. This determines the exhaust exit velocity, and consequently engine specific impulse/SFC. default value = 0.9 (unitless)
This is the fuel heat of burning, or the amount of energy released when a kilogram(?) of fuel is combusted. It is used to help determine the fuel efficiency of an engine. default value = 48.6*10^6 (joules)
This is the burner temperature. It is used along with the fuel heat of burning (FHV) to determine how much energy the combustion chamber adds to the engine. It helps determine the fuel efficiency of an engine. default value = 1200 (Kelvin)
This is the afterburner temperature. It is used along with the fuel heat of burning (FHV) to determine how much energy the afterburner adds to the engine. It helps determine the fuel efficiency of an engine. If no afterburner is present, this should be left at 0. default value = 0 (kelvin)
This determines if an exhaust mixer is present. An exhaust mixer combines the airflow from the engine fan with the air from the engine core, improving engine efficiency. This is only applicable to turbofans, and should be left as "false" for turbojets. default value = false (boolean)
This determines if an adjustable nozzle is present. An adjustable nozzle varies the engine nozzle area to maintain an optimal pressure ratio in all conditions, improving engine performance. This improves engine performance. default value = true (boolean)
This determines if the afterburner uses the same throttle as the engine core. Although normally the afterburner only activates above 66% throttle, this setting causes the afterburner to activate immediately when the engine is started. default value = false (boolean)
This determines if the engine uses a centrifugal flow compressor. Centrifugal flow compressors are less efficient at supersonic speeds, and will significantly reduce the engine compressor efficiency (eta_c) at transonic speeds. default value = false (boolean)
This is the total pressure recovery, or how well the engine inlet turns fast moving, low-pressure air from the airstream into slow, high-pressure air for the engine to use. This is typically around 0.95 for subsonic engines, but decreases for engines designed for operation at high mach. default value = 1 (unitless)
This is the maximum turbine inlet temperature. It determines the maximum internal temperature of the engine, and therefore it's maximum safe Mach. default value = 9999 (Kelvin)
This overrides the intake area of any intakes on the craft to match the Area of the jet engine? default value = false (boolean)
This is a multiplier for the engine Area to allow for slightly smaller intakes to be used. default value = 0.75 (unitless)
This is the idle power setting, or minimum throttle. It determines how much thrust an engine makes while on, but at 0 throttle. It is normally automatically calculated, but can be manually adjusted. Beware, if you set this value too low, the engine exit pressure may become negative and cause an error. Try decreasing CPR or increasing TIT to resolve this default value = 0.01 (unitless)
This is the ratio of turbine area to the engine inlet area (as defined with Area). This is automatically calculated, and probably shouldn't be adjusted. default value = 0.75 (unitless)
This is the specific fuel consumption. This helps determine the engine fuel efficiency and help fit the engine solver. default value = 0 (kg/kgf-h or lb/lbf-h)
This is the maximum static thrust of the engine without afterburner. default value = 0 (kN)
This is the maximum static thrust of the engine with afterburner active. If the engine does not have an afterburner, leave it at 0. This cannot be less than dryThrust. default value = 0 (kN)
This is the idle Nozzle Pressure Ratio, or the pressure inside the nozzle over the ambient pressure while the engine is at idle. This helps determine the minimum thrust of the engine, and fit the engine solver. default value = 1.05 (unitless)
This is the area of the ramjet. It is the primary factor determining the thrust and required intake area of a ramjet. Default value = 0.1 (m^2)
This is the Mach design point. It is used to help fit the engine solver to give more accurate engine performance, but will not directly effect the engine. default value = 0.9 (Mach)
This is the temperature design point. It is used to help fit the engine solver to give more accurate engine performance, but will not directly effect the engine.
Conditions at afterburner exit/nozzle inlet, or nozzle efficiency. This determines the exhaust exit velocity, and consequently engine specific impulse/SFC. default value = 0.9 (unitless)
This is the fuel heat of burning, or the amount of energy released when a kilogram(?) of fuel is combusted. It is the primary factor used to determine the fuel efficiency of an engine, and also indirectly effects thrust. default value = 48.6*10^6 (joules)
This is the maximum fuel to air ratio, or how much fuel can be injected for the amount of air being consumed by the ramjet. Increasing this will greatly increase thrust at lower speeds, but also increase the engine internal temperature. default value = 0.06676 (unitless)
This determines if an adjustable nozzle is present. An adjustable nozzle varies the engine nozzle area to maintain an optimal pressure ratio in all conditions, improving engine performance. Setting this to false on a ramjet appears to cause nonsensical performance results, and should probably be left as default. default value = true (boolean)