A flow boiling experimental investigation was performed to examine the heat transfer coefficient of water and water-TiO2 nanofluid. During investigation, the Reynolds number varied from 8000 to 24,000, pressure from 1 to 2.5 bar, and volumetric concentration of nanofluid from 0.05 to 0.20%. Supplied heat flux was 143 kWm(-2). Experimental results of water were in good agreement with CFD investigation and Chen correlation. It was noticed that the HTC of water and water-TiO2 nanofluid enhanced with the enhancement in Reynolds number and pressure. HTC of water-TiO2 nanofluid was greater than the water and enhanced with the enhancement in volumetric concentration. The highest increment in the HTC of water-TiO2 nanofluid in comparison to water was noticed for Reynolds number 24,000, concentration 0.20%, and pressure 2.5 bar which was 76.7%. Correlations of the HTC of titania nanofluid were developed. To optimize the HTC of water-TiO2 nanofluid desirability function approach was utilized. (C) 2020 Elsevier B.V. All rights reserved.