Difference between revisions of "J-33 "Wheesley" Turbofan Engine"

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m (Added Drag, Temp, Tolerance, Thrust Vectoring, Gimbal Range, Minimum Thrust -> Stall Thrust, Optimal Airflow, Intake Size , Intake Power)
m (Performance and usage)
 
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{{Partbox
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{{:J-33 "Wheesley" Turbofan Engine/Box}}
|Name=Basic Jet Engine
 
|Role=Liquid Fuel Engine
 
|Class=LiquidEngine
 
|File=Basicjetengine.png
 
|Costs=950
 
|Mass=1
 
|Drag=0.2
 
|Temp=3600
 
|Tolerance=7
 
|More=
 
{{PB-more|Fuel Consumption|0.3 L/s}}
 
{{PB-more|Thrust Vectoring|Yes}}
 
{{PB-more|Gimbal Range|2.5°}}
 
{{PB-more|Stall Thrust|20 kN}}
 
{{PB-more|Maximum Thrust|100 kN}}
 
{{PB-more|Optimal Airflow|200}}
 
{{PB-more|Intake Size|1.1}}
 
{{PB-more|Intake Power|125}}
 
|since=v0.15
 
|cfg=Parts/JetEngine/part.cfg
 
}}
 
  
The '''Basic Jet Engine''' is an air-breathing engine which can use liquid fuel from the C7 fuselages or FL-T fuel tanks.
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The '''J-33 "Wheesley" Turbofan Engine''' is an [[Jet engine|air-breathing engine]] which uses [[liquid fuel]] and [[intake air]]. This engine is the second air-breathing engine which can be unlocked in the [[Technology tree|tech tree]], after the [[J-20 "Juno" Basic Jet Engine|J-20 "Juno"]].
  
== Usage ==
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== Performance and usage ==
Unlike rocket engines, a jet draws oxidizer from the atmosphere rather than taking it from an on-board tank. This is represented in-game by a much lower rate of fuel consumption. This engine cannot function effectively at a height of much more than 5km, but it is much more efficient to use jet engines in the lower atmosphere. Jets control a little differently to the rocket engines. The fan in front takes time to change speed, and if the throttle is too low the engine will stall. By contrast, rocket engines give instant response to your control input.
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[[File:J-33 Wheesley Turbofan Engine velocity curve.png|thumb|left|High velocity sharply reduces its thrust.]]
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[[File:J-33 Wheesley Turbofan Engine atmosphere curve.png|thumb|left|Thrust increases with increased air pressure.]]
  
The basic jet engine works at full power on the ground, whereas the [[Turbojet Engine]] won't get up to full power until you're over a kilometer up. However, the turbojet is so much stronger that this advantage doesn't add up to much, and when you consider that the turbojet works at more than twice the altitude there really isn't any reason not to take it instead, as of KSP v0.15.
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Unlike many of the other jet engines (and all of the rockets), this engine is capable of reversing its thrust. This makes it very useful for backing aircraft into hangars and for rapid deceleration during landing. The only other engine capable of this feature is the enormous [[J-90 "Goliath" Turbofan Engine|J-90 "Goliath"]].
  
Currently, jets do not require you to fit air intakes to your spacecraft and function independently of whether you use a fan intake or not.
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[[File:Wheesley plane.png|thumb|left|The wheesley's thrust revert allows planes to have it at the front of its fuselage and still function normally]]
  
== Description ==
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As with all jet engines, its thrust decreases significantly with altitude. Its maximum '''stationary''' thrust is rated at 120 kN at sea level. At about 8,000 m it generates just 48 kN, and at about 15,000 m it generates no more than 13.7 kN, ceasing to work entirely at about 22,900 m, which is remarkeably more than in prior versions (~15,600 m). Note that the behavior between these points (as shown in the part stats) is slightly non-linear.
{{Quote
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|A highly advanced replacement model of the Ax-300 series of engines. This new model features the latest in thrust vectoring and compression technology. This engine is suitable for normal crusing speeds and altitudes.
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Thrust output also varies with '''speed''', although far less than on the more advanced engines. Similar to the other two low-speed engines, its thrust does not increase with speed, in contrast to the high-speed engines. Up to Mach 0.5 the thrust drops to about 80%, recovering to 95% at about Mach 1.5. Going faster, the thrust drops considerably quick, limiting usage to about Mach 2.1. 
|C7 Aerospace Division}}
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 +
The [[Specific impulse|I<sub>sp</sub>]] stays constant over the full range of application, which is a big change compared to KSP in pre-1.0 versions. It is rated at 10,500 s, making it the second most fuel-efficient engine, only the far more advanced 'Goliath' beating it. Being capable of sustained Mach 2 flight even with low tech plane parts, it is a good first choice for medium range flight, while real long range missions may be more convenient with a high speed engine, trading in some fuel efficiency for reduced flight time.
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Overall, it works best between 8,000 and 15,000 m altitude. Flying lower, the high air resistance requires more thrust which lowers the fuel efficiency, while in higher areas the engine's thrust output is simply too low for reasonable performance in flight. A related word of warning: attempting to exceed Mach 1.8 at altitudes below 3,000 m will cause the engine to run exceedingly hot, dumping heat into the rest of the plane faster than it can be dissipated by convective cooling. Even at higher altitudes and with only one engine, heat-sensitive parts like early non-retractable landing gear attached near the engine can be flat-out destroyed from overheating during full-throttle intercontinental flights.
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Note that currently, the only planets which this engine will work on are [[Kerbin]] and [[Jool]]'s moon [[Laythe]].
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== Product description ==
 +
{{Quote|A high bypass turbofan engine. This engine works best at low cruising speeds and altitudes.|manufacturer=C7}}
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== Trivia ==
 +
The designation “J-33 Wheesley” may be a reference to the real-life JT3D turbofan jet engine, also known as the TF33, made by U.S. aerospace company Pratt & Whitney which was involved with the Space Race.
  
  
 
== Changes ==
 
== Changes ==
;{{Version|0.15|}}
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[[File:Basicjetengine.png|thumb|left|100px|Appearance before [[1.0.5]]]]
 +
;[[1.0.5]]
 +
* Remodeled, renamed, new description, and retextured
 +
;[[1.0.3]]
 +
* I<sub>sp</sub> halved, thrust reduced
 +
;[[1.0]]
 +
* complete overhaul of most characteristics
 +
;[[0.15]]
 
* Initial Release  
 
* Initial Release  
  
 
{{Parts}}
 
{{Parts}}
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[[Category:Jet engines]]

Latest revision as of 21:00, 10 July 2024

J-33 "Wheesley" Turbofan Engine
Part image
Jet engine by
C7 Aerospace Division

Radial size Small
Cost (total) 1 400.00 Funds
Mass (total) 1.500 t
Drag 0.2
Max. Temp. 2000 K
Impact Tolerance 7 m/s
Research Tech tree aerodynamics.png Aerodynamics
Unlock cost 4 000 Funds
Since version 0.15
Part configuration jetEngineBasic.cfg
Maximum thrust 120.00 kN
Isp (max) 10500 s
Fuel consumption 0.23 Units of fuel/s
Intake air consumption 29.60 Air unit/s
Thrust vectoring No
Electricity generated 4 ⚡/s
Testing Environments
On the surface Yes
In the ocean Yes
On the launchpad Yes
In the atmosphere Yes
Sub-orbital No
In an orbit No
On an escape No
Docked No
Test by staging Yes
Manually testable Yes
Packed volume None

The J-33 "Wheesley" Turbofan Engine is an air-breathing engine which uses liquid fuel and intake air. This engine is the second air-breathing engine which can be unlocked in the tech tree, after the J-20 "Juno".

Performance and usage

High velocity sharply reduces its thrust.
Thrust increases with increased air pressure.

Unlike many of the other jet engines (and all of the rockets), this engine is capable of reversing its thrust. This makes it very useful for backing aircraft into hangars and for rapid deceleration during landing. The only other engine capable of this feature is the enormous J-90 "Goliath".

The wheesley's thrust revert allows planes to have it at the front of its fuselage and still function normally

As with all jet engines, its thrust decreases significantly with altitude. Its maximum stationary thrust is rated at 120 kN at sea level. At about 8,000 m it generates just 48 kN, and at about 15,000 m it generates no more than 13.7 kN, ceasing to work entirely at about 22,900 m, which is remarkeably more than in prior versions (~15,600 m). Note that the behavior between these points (as shown in the part stats) is slightly non-linear.

Thrust output also varies with speed, although far less than on the more advanced engines. Similar to the other two low-speed engines, its thrust does not increase with speed, in contrast to the high-speed engines. Up to Mach 0.5 the thrust drops to about 80%, recovering to 95% at about Mach 1.5. Going faster, the thrust drops considerably quick, limiting usage to about Mach 2.1.

The Isp stays constant over the full range of application, which is a big change compared to KSP in pre-1.0 versions. It is rated at 10,500 s, making it the second most fuel-efficient engine, only the far more advanced 'Goliath' beating it. Being capable of sustained Mach 2 flight even with low tech plane parts, it is a good first choice for medium range flight, while real long range missions may be more convenient with a high speed engine, trading in some fuel efficiency for reduced flight time.

Overall, it works best between 8,000 and 15,000 m altitude. Flying lower, the high air resistance requires more thrust which lowers the fuel efficiency, while in higher areas the engine's thrust output is simply too low for reasonable performance in flight. A related word of warning: attempting to exceed Mach 1.8 at altitudes below 3,000 m will cause the engine to run exceedingly hot, dumping heat into the rest of the plane faster than it can be dissipated by convective cooling. Even at higher altitudes and with only one engine, heat-sensitive parts like early non-retractable landing gear attached near the engine can be flat-out destroyed from overheating during full-throttle intercontinental flights.

Note that currently, the only planets which this engine will work on are Kerbin and Jool's moon Laythe.

Product description

A high bypass turbofan engine. This engine works best at low cruising speeds and altitudes.

C7 Aerospace Division

Trivia

The designation “J-33 Wheesley” may be a reference to the real-life JT3D turbofan jet engine, also known as the TF33, made by U.S. aerospace company Pratt & Whitney which was involved with the Space Race.


Changes

Appearance before 1.0.5
1.0.5
  • Remodeled, renamed, new description, and retextured
1.0.3
  • Isp halved, thrust reduced
1.0
  • complete overhaul of most characteristics
0.15
  • Initial Release