2 ms·

This type of engine is quite dramatic looking: http://pic60.picturetrail.com/VOL1689/10590113/19957526/325959229.jpg http://pic60.picturetrail.com/VOL1689/1059

by pg 18y ago

This type of engine is quite dramatic looking: http://pic60.picturetrail.com/VOL1689/10590113/19957526/325959229.jpg http://pic60.picturetrail.com/VOL1689/10590113/19957526/3259...

deleted 18y ago
[deleted]
nickb 18y ago
I wonder how they designed it. This looks like something that a GA combined with a CFD solver would create.
- designtofly 18y ago
  As a concept, there is nothing revolutionary about it. This was explored quite a bit back in the 1980s. It is a natural consequence of the physics of how engines operate most efficiently and is well known. So it wouldn't suggest that a GA was necessary to "find" this as a configuration. At this point in time, CFD and the types of tools used in engine design do not lend themselves very well to applications using GA. CFD and other computational tools are very slow (on the order of hours to days) to run and still require a lot of human oversight to produce decent results (so much for physics-based tools, eh?). In addition, it's not quite as simple as a CFD code. It will also have to include the thermodynamic cycle analysis, structural analysis, and noise analysis tools (and dozens of other tools in order to properly assess a possible design). In a very large design space, this would make a zero-order random search method very inefficient. GA are best when the evaluation of the fitness function is computationally inexpensive. That's not to say that there are no applications of GA in aerospace design, but right now they are much more limited in scope. Engine design is incredibly complex. The big engine manufacturers spend several BILLION dollars designing the "core" of the engine alone.
  - eru 18y ago
    I had an offer to develop an library to compute pareto-optimal sets of parameters for car-engines at Bosch. (Pareto-optimal means that you can not get more of a good A (e.g. power) without less of another good B (e.g. efficency) at a point in the set.) (Would have been quite interesting. But I chose to optimize schedules for a railway company instead.)
  - nickb 18y ago
    Thanks for the info. Also, check the amount of research on wings and GAs: http://www.google.com/search?q=wing%20design%20genetic%20algorithm http://www.google.com/search?q=wing%20design%20genetic%20alg... but I haven't looked personally into mixing CFD and GA.
gcv 18y ago
I thought the article said the engine doesn't have a casing, but in the picture, it does. Kind of makes sense though: if I understand jet engines, they must compress air, so the air must be compressed in some kind of container. This design just uses smaller containers.
- ram1024 18y ago
  they were saying there's no casing around the propeller part of the engine, in a turbofan, the casing encloses the blades.
designtofly 18y ago
What's also interesting is how it will affect what airliners look like. These engines pose a very significant problem for integration onto an aircraft. Projected diameters for an engine of this type range from 12-17 feet. Compare this with a diameter of about 56-60 inches on a current high bypass engine as found on a 737. Picture: http://seattletimes.nwsource.com/ABPub/2006/05/09/2002983476.gif http://seattletimes.nwsource.com/ABPub/2006/05/09/2002983476... Article: http://seattletimes.nwsource.com/html/businesstechnology/2002973147_boeingconcepts05.html http://seattletimes.nwsource.com/html/businesstechnology/200...

by pg 18y ago

This type of engine is quite dramatic looking: http://pic60.picturetrail.com/VOL1689/10590113/19957526/325959229.jpg http://pic60.picturetrail.com/VOL1689/10590113/19957526/3259...

deleted 18y ago

[deleted]

nickb 18y ago

I wonder how they designed it. This looks like something that a GA combined with a CFD solver would create.

designtofly 18y ago
As a concept, there is nothing revolutionary about it. This was explored quite a bit back in the 1980s. It is a natural consequence of the physics of how engines operate most efficiently and is well known. So it wouldn't suggest that a GA was necessary to "find" this as a configuration. At this point in time, CFD and the types of tools used in engine design do not lend themselves very well to applications using GA. CFD and other computational tools are very slow (on the order of hours to days) to run and still require a lot of human oversight to produce decent results (so much for physics-based tools, eh?). In addition, it's not quite as simple as a CFD code. It will also have to include the thermodynamic cycle analysis, structural analysis, and noise analysis tools (and dozens of other tools in order to properly assess a possible design). In a very large design space, this would make a zero-order random search method very inefficient. GA are best when the evaluation of the fitness function is computationally inexpensive. That's not to say that there are no applications of GA in aerospace design, but right now they are much more limited in scope. Engine design is incredibly complex. The big engine manufacturers spend several BILLION dollars designing the "core" of the engine alone.
- eru 18y ago
  I had an offer to develop an library to compute pareto-optimal sets of parameters for car-engines at Bosch. (Pareto-optimal means that you can not get more of a good A (e.g. power) without less of another good B (e.g. efficency) at a point in the set.) (Would have been quite interesting. But I chose to optimize schedules for a railway company instead.)
- nickb 18y ago
  Thanks for the info. Also, check the amount of research on wings and GAs: http://www.google.com/search?q=wing%20design%20genetic%20algorithm http://www.google.com/search?q=wing%20design%20genetic%20alg... but I haven't looked personally into mixing CFD and GA.

gcv 18y ago

I thought the article said the engine doesn't have a casing, but in the picture, it does. Kind of makes sense though: if I understand jet engines, they must compress air, so the air must be compressed in some kind of container. This design just uses smaller containers.

ram1024 18y ago
they were saying there's no casing around the propeller part of the engine, in a turbofan, the casing encloses the blades.

designtofly 18y ago

What's also interesting is how it will affect what airliners look like. These engines pose a very significant problem for integration onto an aircraft. Projected diameters for an engine of this type range from 12-17 feet. Compare this with a diameter of about 56-60 inches on a current high bypass engine as found on a 737. Picture: http://seattletimes.nwsource.com/ABPub/2006/05/09/2002983476.gif http://seattletimes.nwsource.com/ABPub/2006/05/09/2002983476... Article: http://seattletimes.nwsource.com/html/businesstechnology/2002973147_boeingconcepts05.html http://seattletimes.nwsource.com/html/businesstechnology/200...