Two phase using Eulerian to Eulerian
 

Dear all, My PhD topic is numerical study about the cooling of the CPV system using nanofluid as a working fluid. The working fluid passing through microcahnnel heat sink of length 127.2 mm and the No. of channel is 70.
My study is two phase using Eulerian to Eulerian. my problem, when i enter the volume fraction of 0.01 or 0.05 for example. the reduction of the solar cell comparing to the base fluid which is water is very small. maximum reduction is 0.8 c at Re=1500 while many papers state the reduction more than 3 or 4 C. Any one can suggest what is the problem.