In our previous work, a traditional compound parabolic concentrator (CPC) was truncated from the positions where multiple reflections exist and a novel CPC with high efficiency and uniform flux was obtained and defined as EMR concentrator. We also figured out that there existed the highest and lowest truncation positions in EMR concentrators, which were defined as HEMR and LEMR concentrators respectively. In the present work, our objective is to design EMR concentrators with various truncation positions and obtain the optimal truncation position. Firstly, based on the geometry topology, EMR concentrators with various truncation positions were designed. Ray tracing simulation of EMR concentrators was conducted by TracePro to figure out their optical efficiencies and irradiance non-uniformities. Results showed optical efficiencies of EMR concentrators with various truncation positions were almost the same, but irradiance uniformities exhibited some difference. On one hand, for EMR concentrators with truncation positions between HEMR and LEMR, irradiance non-uniformity increases slightly with a drop in truncation position firstly and then decreases slightly. On the other hand, for EMR concentrators further truncated than LEMR, irradiance uniformity increases rapidly with a drop in truncation position. Thus, LEMR concentrator is likely to be the EMR concentrator with the optimal truncation position due to its best tradeoff between optical performance and material consumption.
Keywords Compound parabolic concentrator; Eliminating multiple reflections; Optical efficiency; Nonuniform irradiance; Optimal truncation position