VERY HIGH TEMPERATURE FIBER PROCESSING AND TESTING THROUGH THE USE OF ULTRA-HIGH SOLAR ENERGY CONCENTRATION

HIGHER STRENGTH AND LIGHTER WEIGHT FIBER REINFORCED CERAMIC,POLYMER, AND METAL COMPOSITES REQUIRE STRONGER AND MORE THERMALLY STABLE FIBER MATERIALS. SUCH IMPROVEMENTS REQUIRE THE ABILITY TO GROW, PROCESS, AND TEST FIBERS AT HIGHER TEMPERATURES THAN PRESENTLY POSSIBLE IN A PRACTICAL MANNER. THIS PROJECT WILL EVALUATE THE TECHNICAL FEASIBILITY OF PRODUCING, ENHANCING, AND TESTING FIBERS USED IN PRODUCTION OF REINFORCED FIBER COMPOSITES BY APPLYING ULTRAHIGH SOLAR FLUX. GENERALLY, IT IS P PREFERABLE TO HEAT SUCH FIBERS RADIANTLY. TO DO SO PRACTICALLY AT TEMPERATURES HIGHER THAN 1,500 DEGREES CENTIGRADE, ULTRAHIGH SOLAR CONCENTRATION WILL BE USED. IN PHASE I, THE FEASIBILITY OF DEVELOPING A TWO-STAGE NON-IMAGING OPTICAL SOLAR CONCENTRATION SYSTEM TO REACH TEMPERATURES BETWEEN 1,500 DEGREES CENTIGRADE AND THOSE APPROACHING THE SUN'S SURFACE TEMPERATURE WITHIN A SMALL-DIAMETER CYLINDRICAL HOT-ZONE WILL BE ASSESSED. THE PROCEDURES USED PREVIOUSLY TO DEVELOP NON-IMAGING DESIGNS TOCOUPLE THE NEARLY COLLIMATED SOLAR RADIATION TO A POINT OF ULTRAHIGH SOLAR CONCENTRATION WILL BE EXTENDED TO THE PRESENT CASE. AN ANALOGOUS TWO-STAGE FIBER FURNACE THAT PROPERLY COUPLES THE SOLAR ENERGY TO A CYLINDRICAL LINE OF ULTRAHIGH CONCENTRATION WILL BE DESIGNED. COMPUTER PROGRAMS WILL BE DEVELOPED TO DESIGN AND RAY-TRACE THE NEEDED NON-IMAGING ELEMENT. IN THIS MANNER, A COMPLETE SYSTEM SIMULATION WILL BE MADE IN TERMS OF THE SECONDARY OR NON-IMAGING ELEMENT'S INPUT AND OUTPUT FLUX DISTRIBUTIONS AND DEPENDENCE ON OPTICAL DESIGN PARAMETERS. THE INDICATED PROTOTYPE OPTICAL CONCENTRATION SYSTEM WILL THEN BE CONSTRUCTED SO THAT BRASS-BOARD MEASUREMENTS OF THE RESULTING TEMPERATURE CAN BE MADE. BOTH OPTICAL PYROMETRY AND TUNGSTEN WIRE RESISTANCE METHODS WILL BE USED TO CONFIRMAND CALIBRATE TEMPERATURE. IF THE TECHNICAL MERIT OF HIGH TEMPERATURE FIBER PROCESSING AND TESTING THROUGH THE APPLICATION OF ULTRAHIGH SOLAR ENERGY CONCENTRATION IS DEMONSTRATED, A PHASE II PROGRAM TO BUILD AND TEST A WORKINGPROTOTYPE WILL BE CONDUCTED. EXPERIMENTAL RESULTS WILL THENBE USED AND SCALED TO DEVELOP THE DESIGN FOR A PRACTICAL SOLAR FURNACE STATION FOR FIBER PROCESSING AND TESTING.