Talk:Constructal theory

Could someone with a more in-depth understanding of the domains at work here include some more detailed examples? The current text gives the flavor of what I envision this to be, but I still don't really understand it. Skorgu 22:40, 9 February 2006 (UTC)

It's easiest to see with a car or an animal. Let's take a ford car. When ford design a car, they don't always know how heavy/strong the car needs to be to survive in the real world that their customers drive in. So they build it. And in some cases they make mistakes, and bits break more often than they should, so they redesign them. So they have a car that works. However it doesn't stop there (not always), often Ford want to make the car lighter since then it accelerates faster, and by using less materials in making the car, they can make it cheaper, which increases their profit. So they have been known to take a car apart after a hundred thousand miles and find out which bits haven't worn at all, and deliberately make them more cheaply.

So, the end result is an imperfect car, a car that more or less falls apart simultaneously. So, the car is equally imperfect; and this is an optimum design for a car.

In some cases you are able to describe this mathematically; and that allows you to know things about a situation without actually designing the car (or equivalent), or actually tells you stuff about what an optimum car design/shape is that lets you design it.

Hope this helps.WolfKeeper 02:37, 16 February 2006 (UTC)

I have read about constructal theory a few years ago and this is what I have understood to be its main principle: you first optimize the smallest components of a system, then you optimize their arrangement into the system. Thus, for a living organism, the cells must be optimized firstly, then their arrangement into tissues and then the tissues' arrangement in the whole body. The result would be a thoroughly optimized organism. Ferred 10:01, 28 July 2007 (UTC)

Actually, that would be the method of applying constructal theory in engineering. The principle appears in the text: allowing currents to flow easier from source to sink. The diffrerent patterns obtained depend on the geometry of the source and the sink (point, linear, surface, volume sources and sinks) and from the dual nature of the medium between them: there may be a "porous" medium with very little flow or there may be a "channel" with very high flow. In nature, "channels" appear in the "porous" medium due to the tendency of flow to occur with less resistance. Ferred 10:56, 17 August 2007 (UTC)

Is the table under "Principles" is plagiarized from http://www.constructal.org/en/theory/presentation.html (or the other way around?) 24.110.186.216 (talk) 14:48, 28 December 2009 (UTC)

related pages?

this sounds similiar to Stuart_Kauffman's and others in the field of Complex_systems ideas about the role of Self-organization in evolution and biology, and Ilya_Prigogine's ideas on Dissipative_structures in Non-equilibrium_thermodynamics. Kevin Baas^talk 17:16, 12 January 2011 (UTC)

Don't believe it

Wikipedia is an encyclopedia. As such it is purely descriptive. Thanks to wikipedia I now know what constructal theory claims to be. However my problem is that I just don't believe this principle is valid. It doesn't seem to work even in fluid dynamics which the language suggests should be the field it most directly applies to.

Consider a simple case of a fluid flowing through a pipe. Constructal theory would suggest that the fluid should organise its flow in a fashion to optimize throughput. OK - the water flows through the pipe. But now start increasing the pressure difference across the pipe. The flow rate will increase for a while, but at a certain pressure the flow rate will suddenly and drastically decline. This point is called the onset of turbulence. Once turbulence ensues the flow pattern becomes chaotic and the pipe is able to sustain only a much reduced rate of flow. This change happens spontaneously and seems to violate the constructal law.

Or consider meanders in river systems. If the objective is to maximise flow then a nice straight channel would seem to be the ticket. But straight channels are unstable and a river will instead carve out a pattern of meanders which are highly inefficient in terms of maximising throughput.

So is this a problem for Wikipedia? Not necessarily. An encyclopedia isn't an arbiter of correctness, for example the Flat Earth theory has a page. However perhaps my understanding of the law obtained by reading the main page is deficient, in which case a better explanation might be required. If my understanding is correct then in my opinion the constructal law is absolute twaddle. Hawthorn (talk)