Geliş, KadirAkyürek, Eda Feyza2023-06-122023-06-122021Gelis, K., & Akyurek, E. F. (2021). Factorial design for convective heat transfer enhancement of hybrid nanofluids based on al 2 o 3-tio 2 in a double pipe mini heat exchanger. Heat Transfer Research, 52(15).1064-22852162-6561https://www.webofscience.com/wos/woscc/full-record/WOS:000701764600003https://hdl.handle.net/20.500.12491/11104Mini heat exchangers are widely used in various thermal and energy applications due to having advantages such as compactness, lightness, and higher heat transfer performance. With the aim of further improving the performance of such heat exchangers, many recent studies have investigated the use of nanofluids as the working fluid due to their high thermal conductivity. In the present study, two passive heat transfer enhancement methods were used: double pipe mini heat exchanger and hybrid nanofluids. Water at 60 degrees C was used in the shell section of the heat exchanger while Al2O3-TiO2/deionized water hybrid nanofluids prepared at a volumetric ratio of 0.1% and different nanoparticle mixture ratios (100:0, 75:25, 50:50, 25:75, 0:100) were used in the pipe section. This way, the synergistic effects of the hybrid nanofluids were investigated with the double pipe mini heat exchanger. Total heat transfer enhancement (THTE) is a nondimensional number that considers Nu and the friction factor in conjunction. The highest THTE for the Al2O3-TiO2/deionized water hybrid nanofluids was obtained at the Re number equal to 5000 and a nanoparticle mixture ratio of 100:0%, while the minimum value was obtained at a Re 23,000 value and a nanoparticle mixture ratio of 0:100%. The factorial design approach was implemented to design and statistically analyze the experiments. Based on the results obtained, mathematical expressions were derived for Nu and f, and the ability of input parameters to predict results and effective parameters for the Nu and f values were presented statistically with the model obtained.eninfo:eu-repo/semantics/closedAccessMinichannelMini Heat ExchangerDouble PipeHybrid NanofluidFactorial DesignArticle52154162Q3WOS:000701764600003Q3