TY - JOUR
TI - Experimental and numerical investigation on turbulent flow of MWCNT-water nanofluid inside vertical coiled wire inserted tubes
AU - Shahidi Mohamad
AU - Aligoodarz Mohammad Reza
AU - Akhavan-Behabadi Mohammad Ali
AU - Foroutani Saeed
AU - Rahbari Alireza
JN - Thermal Science
PY - 2018
VL - 22
IS - 1
SP - 125
EP - 136
PT - Article
AB - In this paper, heat transfer and pressure drop behavior of MWCNT-water  nanofluid turbulent flow inside vertical coiled wire inserted tubes with  constant heat flux boundary condition were investigated experimentally and  numerically. In the experimental section, plain and five wire coil inserted  tubes were used as the test section's geometries. In the numerical section,  the governing equations associated with the required boundary conditions were  solved using finite volume method based on the SIMPLE technique. The standard  k-ε turbulence model was used in order to simulate the turbulence flow. The  great agreement was found between the obtained experimental and numerical  data with those predicted by the classical correlations for heat transfer and  pressure drop in the plain tube. After validating the achieved data, the  effects of various ranges of Reynolds number, particle weight concentration,  wire diameter and coil pitch ratio on heat transfer coefficient and  performance evaluation criterion (PEC) were declared. It was concluded that  the Nusselt number has been increased up to 102% at the highest Reynolds  number inside the coil wire WC3. Moreover, the maximum enhanced PEC was seen  for the wire coil with lowest coil pitch-to-tube inner diameter ratio (p/d)  and highest wire-to-tube diameter ratio (e/d).