Numerical Analysis of Dual Slot Pulsating Nanofluid Impinging Jets

Jet impingement is a widely utilized technique in engineering, particularly for cooling high-temperature systems like aircraft engines and electronic devices. This study employs numerical analysis to examine the flow dynamics of dual impinging pulsating nanofluid jets, utilizing the ANSYS software platform. This research examines the combined impact of key parameters, including jet geometry, pulsation frequency and amplitude, nanoparticle volume concentration, and Reynolds numbers, on the efficiency of heat transfer. The impact of aluminum oxide (Al₂O₃) nanofluids with varying concentrations (1%, 2%, 4%, and 5%) on thermal performance is assessed. The findings of the study demonstrate that the pulsating jets generate bidirectional swirling flows and reverse vortices upon impact with the surface, resulting in notable enhancements in local heat transfer rates. These vortices expand and form wall jets, which contribute to an increase in the heat transfer coefficients and Nusselt numbers. The simulations demonstrate that higher pulsation frequencies (30 Hz) result in a 10% increase in heat transfer efficiency compared to lower frequencies (10 Hz). This is attributed to enhanced flow dynamics and improved heat distribution. Moreover, the incorporation of nanoparticles markedly enhances heat transfer efficiency. The Nusselt numbers were observed to increase by 18% when the concentration of nanoparticles reached 5%, in comparison to plain water. Additionally, the study underscores the significance of jet spacing, wherein an optimal separation distance of 100 mm between the dual jets was identified as a means of maximizing heat transfer by fostering effective vortex interactions. Higher Reynolds numbers contribute to the formation of thinner thermal boundary layers, thereby facilitating increased heat transfer rates, particularly at the stagnation points where the flow impinges directly on the surface. Overall, the study demonstrates that substantial enhancements in heat transfer can be achieved by optimizing key parameters such as pulsating frequency, amplitude, nanoparticle volume concentration, and jet distances.