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Heat transfer represented by jet impingement was considered due to the grown demand for such applications in the industry such as heat exchangers, metal cutting, and electronic's component cooling. Hence, ZnO/water nanofluid is embraced to enhance the heat exchanged by impinge nanofluid through a square jet. Five nanofluid were prepared thoroughly with different ZnO concentrations range of (0.1–0.5%) besides a plain de-ionized water for comparison. Validation was performed by comparing the outcome with comparable analogous studies and exhibited a content deviation. The parameter (H/Dh) which denotes the (exit of nozzle-to-hot plat spacing over the hydraulic jet diameter) was varied to be 2–8. The acquired results showed that the adoption of nanofluid in such an arrangement gives further magnification in heat transfer (Nu = 113.9%) at high Reynold's number and nanoparticle concentration (φ = 0.5%, Re = 17500, and H/Dh = 2). Whereas the minimum gained heat (Nu = 43.8%) was detected at nanoparticle concentration of (ɸ = 0.1%), Reynold's number of (Re = 5000), and H/Dh spacing of 8 respectively. It was found that applying excessive heat flux on the target plate causes rapid evaporation once the flow hits the surface plate, which leads to poor thermal performance. Eventually, the gained data were correlated and the empirical correlation is proposed.

A solo passive heat transfer enhancement technique represented by nanoparticle additives was embraced in this study due to the nanofluid technology potentials. A single circular jet (3 mm diameter) was used at Reynold number range of (1000–8000) with nozzle-to-jet Distance (Z) varied from 40 to 70 mm. Validation was conducted prior to commence the experimental tests and an accepted deviations were detected. The obtained outcomes showed the potential of CuO-water nanofluid to improve the heat transfer remarkably. Such enhancement increase as both Reynold number and volume fraction increase. Moreover, the Nozzle-to-target plate distance has the dominant effect over the volume fraction effect. Where the heat transfer decreases as the nozzle-to-target plate (Z) increase even if the volume fraction increase. Eventually, the maximum enhancement in Nusselt number was 2.9% and minimum enhancement was about 0.87%. Keywords: Nanofluid, Heat transfer, Impingement jet, Volume fraction, Single jet, Nusselt number

Various techniques have been tested on heat transfer enhancement to upgrade the involving equipment, mainly in thermal transport devices. These techniques unveiled significant effects when utilized in heat exchangers. One of the most essential techniques used is the passive heat transfer technique. Corrugations represent a passive technique. In addition, it provides effective heat transfer enhancement because it combined the features of extended surfaces, turbulators and artificial roughness. Therefore, A Computational Fluid Dynamics was employed for water flowing at low Reynolds number in spiral corrugated tubes. This article aimed for the determination of the thermal performance of unique smooth corrugation profile. The Performance Evaluation Criteria were calculated for corrugated tubes, and the simulation results of both Nusselt number and friction factor were compared with those of standard plain and corrugated tubes for validation purposes. Results showed the best thermal performance range of 1.8–2.3 for the tube which has the severity of 45.455 × 10−3 for Reynolds number range of 100–700. The heat transfer enhancement range was 21.684%–60.5402% with friction factor increase of 19.2–36.4%. This indicated that this creative corrugation can improve the heat transfer significantly with appreciably increasing friction factor.