Two nanofluids of -Al2O3 and Diamond with water base fluid used in rectangular micro channel heat exchanger with heat flux exposed from the bottom side. CFD Fluent is used for the flow calculations. For both nanofluids with grain size of less than 50 nm and concentrations of particles materials 1-5% is used. The Thermal conductivity, heat transfer coefficients, friction factor, pumping power, and pressure drop calculated for the
flow ranging from 500 to 2000 Reynold number . The maximum Temperature attains in the channel at 60 oC for the heat flux of 100 w/cm2 for diamond nanofluid and 80 oC for - Al2O3 nanofluid. The temperature reached above 100 OC for a heat flux of 200 w/cm2 for both nanofluids.
