2.2. Validation
As shown in Fig. 2a, grid independence test was performed for the
studied cavity filled with
Al2O3-MWCNT/water hybrid nanofluid to
analyze the effects of grid sizes on the results for generated grid
mesh. In this section, the Al2O3nanoparticles volume fraction is 0.05 and the MWCNT nanoparticles volume
fraction is 0.01. Furthermore, three different Reynolds numbers are
considered to analyze the effects of various flow velocities on the grid
mesh independency test. As it is seen numerous sets of mesh are
generated and tested versus different Reynolds numbers. By comparing the
results, it is concluded that mesh configuration contains 468986 nodes
is assumed to get a satisfactory agreement between the computational
time and the accuracy of results with the maximum error of 1 percent. It
is realized that for all studied models the appropriate node numbers are
achieved for the case at Re=8000. Therefor for all studied
configurations and cases in present work. The model with 468986 nodes
has been employed. Also, Fig. 2b illustrates images of produced grid
mesh in present study.
Also, the validation was performed by comparison of present numerical
findings and experimental results of Dudley et al. [62] at similar
geometrical dimension and boundary conditions. These results, in case of
energy efficiency variations versus s =
(Tout -Tin )/Ib ,
compressions are displayed in Fig. 3. It can be understood from this
figure that a good agreement (with maximum 10.12% error) exists among
the empirical data of Dudley et al. [62] and numerical findings
gained from present study.