We have designed a Linear Fresnel-type Reflector (LFR) to reduce the area of light concentration based on the caustic surfaces produced by reflection. The LFR is designed by a set of planar mirrors, which appropriately have slopes in such a way that input energy can be focused at predefined absorber area. Also, losses due to riser steps were obtained from a geometrical point of view, to reduce and reconfigure the LFR shape in order to facilitate its manufacture. Finally, a LFR prototype will be fabricated on a single aluminum sheet where their grooves will be molded through CNC machine.
We design two different Hartmann type null screens based on an exact ray trace for testing a fast plano-convex aspherical condenser. The first null screen is designed for testing the external convex surface or periphery area for the condenser by reflection. We have implemented an exact ray trace assuming a point source placed along the optical axis, emitting a bundle of rays, which are reflected by the surface under test, to obtain a non-uniform array of spots, which are printed on paper sheet and wrapped on a plastic cylinder fabricated by using additive manufacture. Subsequently, by reversibility Principle’s after by reflection we obtain a uniform array pattern displayed at the detection plane. Alternatively, to evaluate the whole area for the condenser, the second null screen is designed for testing the central convex area for the condenser by refraction. Thus, we have implemented an exact ray trace assuming an incident plane wavefront, these rays are refracted through the lens under test, to obtain a non-uniform array of drop spots, which are printed on plastic sheet and placed in front of the lens under test. Finally, assuming the reversibility Principle’s after by refraction we obtain a uniform array pattern displayed at the detection plane. For this method, we have called Hartmann type hybrid null screens.
One of the most important components of a wind turbine are the blades, the evaluation of their manufacturing quality and aerodynamic capabilities can be very costly, for this reason a 3D reconstruction by stereo vision is proposed. This technique consists of projecting a laser line in each face of the blade. Using a linear stage, two cameras will scan simultaneously, considering bidirectional disparities and feature correspondences between the two pictures. Two symmetric airfoils of the NACA 0012 family are evaluated. The expected precision is 0.1mm.
We design Fresnel mirrors by using an exact ray tracing considering an incident plane wavefront propagating along the optical axis, impinging at arbitrary reflective surfaces, in order to efficiently redirect the light at a predefined area where will be placed the absorber. The solar concentrator consists of a set of planar mirrors, each one has its own slope in such a way that all the rays impinging on it will be focused at a predefined area as a CPC does. Finally, we provide a qualitative test for a commercial FM based on the null screen method.
A method to design Ronchi-Hartmann screens for testing a fast plano-convex aspherical Fresnel lens is presented. We design null screens that produce either aligned straight fringes or quasi-angular spots arrays for observed patterns. The designs of these null screens are based on knowledge of the caustic by refraction through arbitrary curves. A qualitative test for a Fresnel lens is presented.
In order to evaluate either qualitative or quantitatively the shape of fast plano-convex aspheric lenses, a method to design null screens type Hartmann is proposed. The null screens are formed with non-uniform spots, which allows to have uniform images at detection's plane. The screens are printed on a foil sheet and placed in front of the lens under test, they are illuminated with a collimated monochromatic beam propagating along the optical axis, in such a way that through the process of refraction will form a uniform spot patterns which are recorded at a predefined plane of detection. Finally, processing properly its image recorded we could be able to get a quantitative evaluation of the lens under test. The designs of these null screens are based on the equations of the caustic surface produced by refraction. A preliminary test for a fast plano-convex aspheric lens with F=# = 0:8 is presented in this work. This method could also be applied to alignment of optical systems.
A method to design Ronchi-Hartmann null screens for improved alignment in the testing of fast concave conic mirrors is presented. The designs of these null screens are based on knowledge of the caustic by reflection.
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