Review on the Stability of the Nanofluids

Abstract

Both mono and hybrid nanofluids, the engineered colloidal mixture made of the base fluid and nanoparticles, have shown many interesting properties and become a high potential next-generation heat transfer fluid in various engineering applications. The present review focuses on improving the stability of the nanofluids. For this, the present review briefly summarizes the impact of nanofluid preparation on the stability of various nanofluids and described in the following classification; (a) Nanofluid constituent, (b) Nanomaterial synthesis, and (c) Nanofluid synthesis techniques which are well-grouped and thoroughly discussed. Physical mechanisms for heat transfer enhancement using nanofluids are explored as well. Most of the studies reveal that there are significant improvements in the stability of the nanofluids. Hence, there is an excellent opportunity to use stabled nanofluids in various engineering applications. Finally, some useful recommendations are also provided.

Studies on Evaluation of the Thermal Conductivity of Alumina Titania Hybrid Suspension Nanofluids for Enhanced Heat Transfer Applications

“…It reduces the number of experiments to be conducted and provides the optimal solution. Taguchi’s L 9 OA is chosen for 3 process parameters ( n p = 3) such as ϕ 1 , ϕ 2 , and T with 3 levels ( n l = 3) using the formula N Taguchi = 1 + n normalp × ( n l − 1 ) …”

“…The stability of nanofluids can be improved by preparing the nanofluids through an expensive and complex single-step method. 33 In fact, the simple two-step method is being adopted in the preparation of nanofluids by the majority of researchers (95%), and it does not require any sophisticated apparatus. For better dispersion of nanoparticles, 3−10 h of sonication time is required.…”

“…The stability of nanofluids was examined by ζ potential measurements in addition to the visual observations. The stability of nanofluids can be improved by preparing the nanofluids through an expensive and complex single-step method …”

“…The stability of nanofluids can be improved by preparing the nanofluids through an expensive and complex single-step method. 33 …”