THE USE OF SOLID PARTICLES AS A HEAT TRANSFER MEDIUM IS BEING PURSUED AS A LEADING PATHWAY FOR GEN3 CSP SYSTEMS OPERATING AT TEMPERATURES OVER 700 OC. THESE HOT PARTICLES FLOW ALONG WITH THE DIFFERENT COMPONENTS OF THE RECEIVER, COLLECTOR, HEAT EXCHANGER, AND STORAGE SYSTEM DURING OPERATION, RESULTING IN MATERIAL DETERIORATION DUE TO EROSION AND ABRASION WEAR. FURTHER, THE HEAT EXCHANGER WALLS ARE SUBJECT TO ABRASION WEAR DURING CONTINUOUS OPERATION. A FUNDAMENTAL UNDERSTANDING OF MATERIAL DEGRADATION DUE TO EROSION AND WEAR MECHANISMS AND DEVISING WAYS TO MITIGATE THE DEGRADATION IS NECESSARY TO ENSURE SYSTEM DURABILITY THROUGHOUT THE LIFE OF THE CSP PLANT. THE EXTENT OF EROSION DEPENDS ON MANY FACTORS, INCLUDING BUT NOT LIMITED TO PARTICLE SHAPE AND SIZE, PARTICLE HARDNESS, MATERIAL HARDNESS/BRITTLENESS, DUCTILITY, PARTICLE IMPACT VELOCITY, AND IMPACT ANGLE. IN THIS PROJECT, WE SEEK TO STUDY THE EFFECT OF THE SOLID PARTICLES ON MATERIAL EROSION (WHEN PARTICLES IMPINGE ON A SURFACE) AND WEAR (WHEN PARTICLES FLOW ALONG A SURFACE) THROUGH A COMPREHENSIVE DESCRIPTION OF THE UNDERLYING PHYSICS AND MECHANISMS. A COMPUTATIONAL MODEL OF THE SOLID PARTICLES FALLING FROM THE RECEIVER INTO THE COLLECTOR AND MOVING IN THE PARTICLE HEAT EXCHANGER AND FLOW COMPONENTS WILL BE DEVELOPED TO INVESTIGATE THE EROSION AND WEAR EFFECTS. WITH THE UNDERSTANDING OF EROSION AND WEAR OF SURFACES FROM COMPUTATIONAL MODELING, SUITABLE EROSION-RESISTANT COATINGS WILL BE DEVELOPED TO MINIMIZE EROSION AND WEAR IN TARGETED AREAS. THE VALIDATED MODEL WILL PREDICT THE OPERATIONAL LIFE OF THE CSP COMPONENT AND SOLID PARTICLES. THE OVERALL GOAL OF THE PROJECT IS TO DEVELOP A PHYSICS-BASED COMPUTATIONAL MODEL CONSIDERING VARIOUS PARAMETERS AFFECTING SURFACE WEAR AND VALIDATE IT FOR DIFFERENT MATERIALS FOR HIGH-TEMPERATURE APPLICATIONS. BASED ON THE COMPUTATIONAL MODEL, THE OPERATIONAL LIFE OF CSP COMPONENTS WILL BE PREDICTED. INFORMED BY THE COMPUTATIONAL MODELS AND COMPLEMENTARY EXPERIMENTAL STUDIES, EROSION-RESISTANT COATINGS WILL BE DEVELOPED TO IMPROVE THE LIFE SPAN OF CSP COMPONENTS WITHOUT AFFECTING THE DESIRABLE PROPERTIES OF THE BASE MATERIALS. THE OPERATIONAL LIFE OF COATINGS ON VARIOUS SUBSTRATES WILL BE PREDICTED USING A COMPUTATIONAL MODEL WHICH DEMONSTRATES A LOWER EROSION RATE WHEN EXPOSED TO HIGH-TEMPERATURE FALLING PARTICLES AS A HEAT TRANSFER FLUIDS MEDIUM. SPECIFICALLY, WE WILL: 1. IDENTIFY VARIOUS MATERIALS /COMPOSITES THAT CAN BE USED FOR CSP COMPONENTS. FURTHER, THE PARTICLE MATERIAL WILL ALSO BE IDENTIFIED WITH THEIR THERMOPHYSICAL PROPERTIES. 2. IDENTIFY CSP SYSTEM COMPONENTS WHERE EROSION OCCURS AND DEVELOP AN EROSION MODEL FOR PARTICLE IMPACT. DEVELOP EROSION AND ABRASION MODEL TO PREDICT THE WEAR DEPTH ON VARIOUS LOW-COST CONVENTIONAL METALLIC ALLOYS. CONDUCT DETAILED STUDIES TO CHARACTERIZE EROSION DEPTH AND RATE AND PREDICT THE COMPONENT'S LIFE SPAN. DEMONSTRATE PERFORMANCE IMPROVEMENTS BY APPLYING ADDITIONAL COATINGS ON AREAS WHERE EROSION OCCURS AND SYSTEMATICALLY ELUCIDATE THE INFLUENCE OF VARIOUS OPERATING PARAMETERS ON THE RESULTING COATING PERFORMANCE, AND FROM THESE STUDIES, DERIVE OPTIMAL MATERIAL AND DESIGN PARAMETER COMBINATIONS FOR VARIOUS COATINGS. 3. DEVELOP WEAR-RESISTANT COATINGS BASED ON IDENTIFIED AREAS TO MITIGATE THE WEAR. FURTHER, THE STUDIES WILL BE CONDUCTED BY EXPOSING THE WEAR-RESISTANT COATING TO TYPICAL HIGH-TEMPERATURE PARTICLES FALLING ON THE COATING TO DEMONSTRATE REDUCED WEAR VIS-À-VIS NON-COATED SURFACES. 4. DEVELOP A BEST ESTIMATE COST MODEL FOR WEAR RESISTANT COATINGS ON CSP COMPONENTS TO OPTIMIZE DESIGNS FOR THE LEAST COST. THE PROJECT'S FINAL DELIVERABLE WILL BE FUNDAMENTAL PHYSICS BASED MODELS AND COMPUTATIONAL SIMULATION TOOLS FOR WEAR AND A LABORATORY-SCALE DEMONSTRATION OF EROSION AND WEAR-RESISTANT COATING MATERIALS.