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

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(J-33 may be JT3D crossed with TF33.)
(nearly omplete rewrite due to KSP 1.0 changes)
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== Usage ==
 
== Usage ==
This engine cannot function effectively at a height of much more than 10&nbsp;km, but it is much more efficient to use jet engines in the lower atmosphere. The basic jet engine works at full power while stationary, whereas the [[TurboJet Engine]] won't get up to full power until it reaches 1000 meters/second surface velocity. This makes it ideal for low-flying [[plane|aircraft]], as the engine has a thrust of about 150 kilonewtons on the runway and an I<sub>sp</sub> of about 850. However, for high-flying aircraft, the TurboJet engine should still get you off the runway.
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This engine is the first air breathing engine to unlock in the tech tree. Technically it is also the most basic one, hence the name.
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As on all engines, thrust varies with height. Contrary to all rocket engines, air breathing engines' thrust diminishes with increasing height. Furthermore differing from most rocket engines, this has a real impact on usage, as the effect is far more distinct.
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Its maximum '''stationary''' thrust is rated with 115 kN at sea level. At about 4500 m it generates just 69 kN, at about 11000 m it generates not more than 22 kN, ceasing to work at about 15600 m. Note that  the behaviour between thes points (given in the part stats)is somewhat non-linear, especially above 4000 m.
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Thrust output also varies with '''speed''', although far less then on the more advanced engines. Up to mach 0.8 it stays somewhat constant, slightly rising to a maximum of about 170% at mach 1.6 .. 1.8, dropping to zero at mach 2.5.
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The fuel-to-thrust ratio (also called Isp in some circles) stays constant over the full range of application, which is a big change to KSP pre 1.0 versions. It is rated at 19200 s, making it by far the nominal most fuel efficient engine. However, as the thrust/height curve of this engine limits its usage to still quite thick air, this value is somewhat put into perspective.
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All in all it works best at 8000 .. 12000 m height. Flying lower, the high air resistance eats up the fuel efficiency (you need far more thrust to achieve the same speed), while in higher areas the engines thrust output is just too low for reasonable flight.  
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Note that currently, the only planets which these engines will work on is [[Kerbin]], and Jool's moon [[Laythe]].
 
Note that currently, the only planets which these engines will work on is [[Kerbin]], and Jool's moon [[Laythe]].

Revision as of 17:59, 4 June 2015

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 Basic Jet Engine is an air-breathing engine which uses liquid fuel and intake air.

Usage

This engine is the first air breathing engine to unlock in the tech tree. Technically it is also the most basic one, hence the name. As on all engines, thrust varies with height. Contrary to all rocket engines, air breathing engines' thrust diminishes with increasing height. Furthermore differing from most rocket engines, this has a real impact on usage, as the effect is far more distinct.

Its maximum stationary thrust is rated with 115 kN at sea level. At about 4500 m it generates just 69 kN, at about 11000 m it generates not more than 22 kN, ceasing to work at about 15600 m. Note that the behaviour between thes points (given in the part stats)is somewhat non-linear, especially above 4000 m.

Thrust output also varies with speed, although far less then on the more advanced engines. Up to mach 0.8 it stays somewhat constant, slightly rising to a maximum of about 170% at mach 1.6 .. 1.8, dropping to zero at mach 2.5.

The fuel-to-thrust ratio (also called Isp in some circles) stays constant over the full range of application, which is a big change to KSP pre 1.0 versions. It is rated at 19200 s, making it by far the nominal most fuel efficient engine. However, as the thrust/height curve of this engine limits its usage to still quite thick air, this value is somewhat put into perspective.

All in all it works best at 8000 .. 12000 m height. Flying lower, the high air resistance eats up the fuel efficiency (you need far more thrust to achieve the same speed), while in higher areas the engines thrust output is just too low for reasonable flight.


Note that currently, the only planets which these engines will work on is Kerbin, and Jool's moon Laythe.

Product description

A standard air breathing engine. This model utilizes limited range thrust vectoring. This engine works best at low cruising speeds and altitudes.

Created by: C. Jenkins

Triva

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

0.15
  • Initial Release