The subject of this research was laminar flow of ionic-nanofluid through a horizontal tube with circular cross-section. The aim of this research was investigating of forced convection and hydraulic characteristics in a straight pipe section using computational fluid dynamics (CFD). Verification of numerical simulation data is executed in two ways: with water flow through a pipe, and comparation between a pressure drop results from simulation and the pressure drop obtained from the Darcy - Weisbach equation. Shash's equation was used for calculation of Nusselt's number and it was compared with Nusselt number calculated from CFD simulations results for the purpose of numerical simulation result verification. To check weather using of examined ionic nanofluid is meaningful in heat transfer systems, a few criteria was used. Results of numerical simulations was successfully verified, and it was found that examined fluid meets the criteria for mass concentrations of 0.5 % and 1 % nanoparticles and inlet temperature of fluid T=335 K.