Why smooth dome ? Why not multi sided stepped dome ?

[Tman1]

Re: Why smooth dome ? Why not multi sided stepped dome ?

I didn't tell her what I was doing, just to make some pizza dough. You already need the bricks, it's just a test version.


A good start to the addiction. A true pompeii is in my future.

[GianniFocaccia]

Re: Why smooth dome ? Why not multi sided stepped dome ?

I am merely paraphrasing directly from Wikipedia, but my brief inquiry into the properties of thermal radiation reveals that radiated heat acts in a linear, fluid manner, not unlike sound or light. Also, thermal radiation emitted by a body at any temperature consists of a wide range of frequencies, and the dominant frequency (or color) range of the emitted radiation shifts to higher frequencies as the temperature of the emitter increases.

Further, unlike conductive and convective forms of heat transfer, thermal radiation can be concentrated in a tiny spot by using reflecting mirrors. (This is how solar energy is concentrated).

I deduce from this that the discreet reflective surfaces of our hemispherical brick domes do indeed radiate heat directly at the center of our ovens, supporting dave s' theory as well as the gazillions of ovens built since the beginning of time!

[Tscarborough]

Re: Why smooth dome ? Why not multi sided stepped dome ?

Also points and corners will get hotter, faster than a smooth surface and may deteriorate quicker. There is still no significant reason why it won't work reasonably well, though.

[Neil2]

Re: Why smooth dome ? Why not multi sided stepped dome ?

Domes are compression structures. I won't go into the engineering involved but all domes are smooth not stepped for a reason.

Besides, trying to build it "stepped" seems to be more complicated that the "normal" way (which has been in use for two thousand years or more).

[stoveup]

Re: Why smooth dome ? Why not multi sided stepped dome ?

I tend to think of a dome as a series of arches that all meet at the keystone at the top of the dome. There are many examples of corbelled arches built hundreds of years ago - especially on the Indian subcontinent and in the Moorish architecture of Spain.

I see no reason a corbelled dome would not work, but I am not sure it would be possible to maintain the relatively thin cross section of the dome shell and be structurally sound. Corbels are simply a series of increasingly projected cantilevers. For a cantilever to work, the weight of the unsupported section must be less than the weight of the supported section. As the corbels progress further and further out, more weight has to be added to the lower courses to support those above creating a thicker cross section and more thermal mass.