Numerical and Optimization-Based Study on Split Hemispherical Shaped Fins for Augmenting Heat Transfer Rate

Abstract

This paper deals with the numerical investigation of split hemispherical fins mounted staggered over a base plate. The thermal and flow analyses have been carried out to evaluate the Nusselt number (Nu), pressure drop $\left(\Delta P\right)$ , and hydrothermal performance factor (HTPF) with air as a medium and Reynolds number ( $\mathrm{Re}=/3000$ to 15000). The cylindrical fin (CF) and hemispherical fin (HF, of radius $R$ ) of the same volume and height have been formed and placed in the computational domain. Results reveal that the Nu for CF compared to HF is 1.3-1.4 times higher, with approximately 1.5 times higher $\Delta P$ for the given Re range. The value of HTPF for HF is greater than unity (/1.13-1.20) for all the considered Re values. Secondly, the HF gets split into longitudinal and transverse flow directions for better solid-fluid interaction. The geometrical parameters are transverse offset TO (/= $0-R/8$ ), longitudinal offset LO (/= $0-R/8$ ), and Re. Results show that the highest value of Nu (/=384.10) and HTPF (/=1.33) have been obtained at $\text{TO}=R/10$ (at LO =0) and $\text{TO}=R/10$ (at $\text{LO}=R/10$ ) for the highest Re (/=15000). At last, the cuckoo search algorithm (CSA) coupled with the response surface method (RSM) has been performed to fetch the optimum value of Nu based upon dimensionless TO ${}^{\ast }$ , dimensionless LO ${}^{\ast }$ , and Re. The optimum value (obtained at ${\text{TO}}^{\ast }=0.1$ , $\text{L}{\text{O}}^{\ast }=0$ , and $\mathrm{Re}=15000$ ) of Nu (=/392.16) from CSA is promising, with the numerically obtained Nu value (=/384.1059) with an error of 2.05%.