Designing a cooling system is crucial for the thermal management of many different types of energy applications, such as fuel cells, solar panels, electronic cooling, and many more. A higher local heat transfer coefficient is attained by impinging jets, making them a viable cooling option. This study investigates a two-dimensional numerical study into the turbulent convective heat transfer in a confined slot and submerged impinging jet by using water and a nanofluid for Reynolds numbers between 6000 and 24000. The nanofluid of lamina-shaped CoFe3O2/water has been studied, with the volume concentration of nanoparticles ranging from 2.0% to 4.0%. Using a finite volume technique based on the SIMPLE algorithm, the governing momentum, continuity, and energy equations are solved. A presentation and discussion of the influence of the nanoparticle's volume fraction and the Reynolds number on the flow and thermal properties are provided. Increasing the volume fraction of nanoparticles is shown to enhance the Nusselt number and the Darcy friction factor. Entropy generation increases with the increase of the Reynolds number for all working fluids.