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It's funny, because in my much younger days I dropped out of college and worked as a mechanic for 3 years. In the automotive world and internal combustion Worl
by joncrane 8y ago
It's funny, because in my much younger days I dropped out of college and worked as a mechanic for 3 years. In the automotive world and internal combustion World, manifold has a much different meaning, though related.
Basically, a manifold means something that takes the flow of gases from a one-to-many or a many-to-one.
An intake manifold takes one single entry point for air feeding the engine and splits up into a separate input for each cylinder.
An exhaust manifold takes the hot exhaust from each cylinder separately and combines them into one big pipe.
- tyingq 8y agoThat's what manifold means to me as well. Though, there are exceptions to the "one" part, like intake manifolds with two inlets (dual plane is common), exhaust manifolds with two outlets (common on inline 6 engines), and also some really odd setups: https://speedmaster79.com/media/catalog/product/cache/1/thumbnail/9df78eab33525d08d6e5fb8d27136e95/p/c/pce148.1086_2.jpg https://speedmaster79.com/media/catalog/product/cache/1/thum...
- joncrane 8y agoThat picture looks like an intake for a V8 and each trumpet is still for an individual cylinder; it's just that the intake ports on the heads are paired up for manufacturing and thermal efficiency.
- tyingq 8y agoMy point was that manifolds aren't all many to one. This one is clearly many to many.
- commandlinefan 8y agoI actually clicked the link expecting exactly that explanation.
- Topolomancer 8y agoSorry! It just goes to show that I am living in a filter bubble of mathematics. My intention was not to deceive you :-)
- Sharlin 8y agoNo need to apologize. Words have different meanings.
- commandlinefan 8y agoNot at all - I got more than I bargained for and learned something new!
- Topolomancer 8y agoSorry, I was not aware of that! It was not my intention to mislead you. Hope you enjoyed the article nonetheless :-)
- tyingq 8y agoPlenum is also used to describe automotive intakes, and has a physics meaning as well.
- steve76 8y agoI took apart a furnace once to replace an igniter. I was thinking I was going to find a series of pipes or tubes fitted together. Instead I found just two pieces of pretty thick sheet metal, close to plate thickness. They just went through a metal bender to form the pipes, and bolted together with a gasket in between. Maybe that's how it got started. A plane, wrapped around something.
- wck0 8y agoAnd I always think of the mathematical definition. It's nice to see the mechanical terminology explained. Thanks!
- TeMPOraL 8y agoIsn't this like a multiplexer/demultiplexer in electronics/signal processing?
- inamberclad 8y agoA multiplexer/demux takes one of many inputs and routes them to a single output, or vice versa. A manifold has no valving, so it's a mixer/adder instead.
- jazzyjackson 8y agoYou could at least say that the ground plane on a circuit board is an exhaust manifold
- dnautics 8y agoThis is also the general usage for chemists... As a chemistry and math major during my college days it was confusing to say the least.
- mindcrime 8y agoA similar notion exists in the fire service, where a manifold is an appliance for combining or splitting water supply lines. A typical example of a fire service manifold would be an appliance with 3 2.5" threaded ports and a single 5" Storz port, which can be used to either merge multiple 2.5" or 3" supply lines into one 5" supply line, or to divide the flow from a 5" line up into multiple smaller lines. Example: http://fireflowtechnology.com/wp-content/uploads/2015/04/100_0043-300x225.jpg http://fireflowtechnology.com/wp-content/uploads/2015/04/100...
- loeg 8y agoAnd on a smaller scale, ordinary water plumbing :-).
- adrianratnapala 8y ago> Basically, a manifold means something that takes the flow of gases from a one-to-many or a many-to-one. A perfectly sensible meaning given the construction of the word. There is something about mathematics and linguistics (and to some extent CS) that encourages the creation of confusing, meaningless names like "accusative (case)", "(algebraic) ideal" and "(geometric) manifold".
- tomxor 8y agoI don't think "encouragement" is quite right, ambiguities are somewhat the default - it's the opposite of encourage, an absence of something, there must be a competitive force present to reduce their likelihood. I think there are less ambiguities in common language because they share so much context and compete; where as there is enough separation between certain disciplines for the semantics of esoteric words to evolve and coexist independently without issue until viewed externally where it appears ambiguous - this is even true for mathematical notations.
- JadeNB 8y ago> A perfectly sensible meaning given the construction of the word. There is something about mathematics and linguistics (and to some extent CS) that encourages the creation of confusing, meaningless names like "accusative (case)", "(algebraic) ideal" and "(geometric) manifold". Confusing is hard to argue, but meaningless is, I think, hard to defend. These all have meanings; I could speak to the latter two, and I'm sure a linguist could speak to the former. They may not be obvious meanings, but that's not the same as saying they're meaningless. (I regard much business jargon, for example, as literally meaningless, defined only in terms of other words that also seem meaningless to me; but I'm sure an MBA would take issue with that characterisation.) I don't know who coined 'manifold', but 'ideal', for example, was literally Kummer's word coined to describe things that behaved like, but weren't quite, numbers in the ordinary sense (https://en.wikipedia.org/wiki/Ideal_number https://en.wikipedia.org/wiki/Ideal_number )—much like the "ideal points" of hyperbolic geometry (https://en.wikipedia.org/wiki/Ideal_point https://en.wikipedia.org/wiki/Ideal_point). (EDIT: Fortunately no_identd knows more about the history of 'manifold' than I do (https://news.ycombinator.com/item?id=19659571 https://news.ycombinator.com/item?id=19659571).)
- loeg 8y agoDitto plumbing (liquids), e.g., https://www.supplyhouse.com/Bluefin-CM4-75PXZ-PXV-3-4-PEX-Crimp-x-Closed-Copper-Manifold-w-1-2-PEX-Crimp-Ball-Valves-Lead-Free-4-Outlets https://www.supplyhouse.com/Bluefin-CM4-75PXZ-PXV-3-4-PEX-Cr...
- Razengan 8y ago> An exhaust manifold takes the hot exhaust from each cylinder separately and combines them into one big pipe. Does that have anything to do with “many-fold?”
- simonh 8y agoYes, the original Old English was Manigfeald which means exactly that.