Parabolic trough

The parabolic trough is a parabolic trough. In guided perpendicular to the channel axis cut the concave boundary line is a parabola.

Compared to limited with a parabolic paraboloid of revolution can be implemented as a simple curved concave mirror are reflected to the incident plane waves so that they run on a line ( line focus ).

When used as a light - mirror parabolic troughs has properties similar to a cylinder lens.

Focal property of parabolic surfaces

A parabola can be defined as follows:

" A parabola is the locus of all points P whose distance to a special fixed point - the focal point F - equal to a specific line - the directrix l -. 's " ( See chart)

The perpendicular bisector PG is the tangent to the parabola at P. It forms with the PF beam and the normal incident beam at the same angle, so the latter is reflected in the direction of F, the focal point.

By shifting a parabola along a straight line perpendicular to the plane containing them, the inner surface of a parabolic trough is formed.

Application

Incoming parallel rays are focused into a line, or emanating from this line rays are emitted parallel.

Solar panels

Beamforming in a line:

Parabolic trough are used in parabolic trough power plants and solar panels. Here, a tube is concentric with the focal line, in which a heat carrier medium, for example oil, is heated by the sun. In contrast to the mostly two-axis parabolic mirror mounted parabolic troughs in the use of solar energy is only tracked to the elevation angle of the sun in one axis, this is easier to implement and therefore less expensive to purchase and maintain.

Glow

Collimating of a line emanating rays:

Reflectors in lights are often parabolic trough when an elongated bulbs used.

Strobe lights, the (mostly in the vertical) obtain in this way a pooling, occur not only in photography, it is also found in the lightbar of vehicles of police, firefighters and emergency medical personnel.