Design and test of a trumpet secondary concentrator for a faceted stretched membrane primary in a dish-Stirling application

A ``trumpet`` type nonimaging secondary concentrator has been designed and a prototype fabricated for test with the Cummins Power Generation (CPG) 7.5 kW{sub e} dish-Stirling system. Trumpets are families of hyperbolae of revolution which can be characterized by three parameters, the exit aperture radius, the asymptotic angle, and the truncation height. The test prototype unit was designed using a detailed ray trace code to simulate the radiation distribution from the primary and modeling the performance across a range of these trumpet design parameters. The unit is 26.7 cm (10.5 in.) deep by about 69 cm (27 in.) wide, and has a geometric concentration of 1.7X. The test units were fabricated from polished copper spinnings, overcoated with vapor deposited aluminum and aluminum oxide layers and are water cooled. The objectives and test procedures for the experiments are reviewed.