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A convex mirror diagram showing the focus, focal length, centre of curvature, principal axis, etc. A convex mirror or diverging mirror is a curved mirror in which the reflective surface bulges towards the light source. [1] Convex mirrors reflect light outwards, therefore they are not used to focus light.
In many real-life applications (e.g. heat losses at solar central receivers or cooling of photovoltaic panels), natural and forced convection occur at the same time (mixed convection). [4] Internal and external flow can also classify convection. Internal flow occurs when a fluid is enclosed by a solid boundary such as when flowing through a pipe.
Basic diagram of a focusing schlieren system. The basic idea is that the illumination pattern is imaged onto a geometrically congruent cutoff pattern (essentially a multiplicity of knife edges) with focusing optics, while density gradients lying between the illumination pattern and the cutoff pattern are imaged, typically by a camera system.
Simplified geodynamo models have shown relationships between the dynamo number (determined by variance in rotational rates in the outer core and mirror-asymmetric convection (e.g. when convection favors one direction in the north and the other in the south)) and magnetic pole reversals as well as found similarities between the geodynamo and the ...
Another form of convection is forced convection. In this case, the fluid is forced to flow by using a pump, fan, or other mechanical means. Convective heat transfer , or simply, convection, is the transfer of heat from one place to another by the movement of fluids , a process that is essentially the transfer of heat via mass transfer .
Convection is often categorised or described by the main effect causing the convective flow; for example, thermal convection. Convection cannot take place in most solids because neither bulk current flows nor significant diffusion of matter can take place. Granular convection is a similar phenomenon in granular material instead of fluids.
A fixed parabolic mirror creates a variously shaped image of the sun as it moves across the sky. Only when the mirror is pointed directly at the sun does the light focus on one point. That is why parabolic dish systems track the sun. A fixed spherical mirror focuses the light in the same place independent of the sun's position. The light ...
These first Heisler–Gröber charts were based upon the first term of the exact Fourier series solution for an infinite plane wall: (,) = = [ + ], [1]where T i is the initial uniform temperature of the slab, T ∞ is the constant environmental temperature imposed at the boundary, x is the location in the plane wall, λ is the root of λ * tan λ = Bi, and α is thermal diffusivity.