Effect of zinc oxide-water nanofluids on the thermal efficiency of a flat plate solar collector – a comparative analysis of central composite design and box Behnken design
Abstract
Comparative analysis of response surface methodology (RSM) using central composite design (CCD) and box-Behnken design (BBD) in thermal efficiencies of a solar water heating system is undertaken. CCD and BBD were applied to data obtained from an experimental study that studied the effect of zinc oxide-water nanofluids on a pumped solar thermal system with a flat plate collector. The two methods were then compared in terms of the coefficient of determination and the P-values of the models. The results showed that Box Behnken Design yielded a model with a higher coefficient of determination (R2) of 85.88%, while Central Composite Design gave a coefficient of determination of 77.78%. It is concluded that the Box Behnken Design achieves a better-fitting model with fewer experimental runs. On the other hand, Central Composite Design gave a more accurate model that had a p-value of 0.007 in comparison to 0.097 for Box Behnken Design. Consequently, CCD is a better option when producing an accurate model while BBD is preferred for making models with a good fit.