Knowing Parabolic Concentrators

This image shows a large parabolic concentrator focussing sunlight at the smaller parabola in the middle which in turn does the opposite i.e. it turns the focussed light into a parallel, but narrow beam of light.
{Click on the image for larger view; (will open in a new window)}



A word about the parabolic shape;
A Parabola is the name given basically to the shape generated when a conic section {A birthday hat oppositely placed over another} is cut by a plane {say a plane sheet of metal} along its side. Mathematical analysis of the cut surface shows a distinct property, every point on a parabolic curve is equidistant from a point and a line. The point is called Focus and the Line is called Directrix. See below.

This property of a parabolic curve leads us to an equation which is used to describe a parabola.

Where 'x' and 'y' are cartesian coordinates { see the big '+' sign in above graph, horizontal line is X-axis and vertical line is Y-axis}. And, 'f' is the focal point of the curve.


The parabolic concentrator you saw in the topmost image is an exact one. Its mathematical equation is:
If you compare this equation with the above one, you'll see that 'f' here is 5 units. So, the focal point of our parabola is 5 units.





Take a look once again, this time with the graph imposed on it {click on the image for larger view};



A parabolic concentrator needs to track the Sun to maintain focus. Sunlight at the focal point of a moderate size parabola is intense enough to cook anything.

Do you want to eat some food cooked on Sunlight, get a cooker first. For more info visit solarcookers.org

These type of reflectors are used in solar power-plants. Visit: www.energylan.sandia.gov/sunlab/overview.htm

All images in this post are my own!
Coming up in a few days a new "easy read" feature which I've developed for this blog. Reading paragraphs with the use of such technique will become very easy. It's a 'Flash' based feature.
Regular updates will continue.
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