In this study, thermal-hydraulic performance of a confined slot jet impingement with Al2O3-water nanofluid has been numerically investigated over Reynolds number ranges of 100-1000. Two triangular ribs are mounted at a heated target wall; one rib located on the right side of the stagnation point and another one located on left side of the stagnation point. The governing momentum, continuity and energy equations in the body-fitted coordinates terms are solved using the finite volume method and determined iteratively based on SIMPLE algorithm. In this study, effects of Reynolds number, rib height and rib location on the thermal and flow characteristics have been displayed and discussed. Numerical results show an increase in the average Nusselt number and pressure drop when Reynolds number and rib height increases. In addition, the pressure drop and average Nusselt number increases with decrease the space between the stagnation point and rib. The maximum enhancement of the average Nusselt number is up to 39 % at Reynolds number of 1000, the rib height of 0.3, rib location of 2 and nanoparticles volume fraction of 4%. The best thermal-hydraulic performance of the impinging jet can be obtained when the rib height of 0.2 and rib location of 2 from the stagnation point with 4% nanoparticles volume fraction.
This article presents a numerical study on forced convection of nanofluid flow in a two-dimensional channel with trapezoidal baffles. One baffle mounted on the top wall of channel and another mounted on the bottom wall of channel. The governing continuity, momentum and energy equations in body-fitted coordinates are iteratively solved using finite volume method and SIMPLE technique. In the current study, SiO2-water nanofluid with nanoparticles volume fraction range of 0- 0.04 and nanoparticles diameters of 30 nm is considered for Reynolds number ranging from 100 to 1000. The effect of baffles height and location, nanopar-ticles volume fraction and Reynolds number on the flow and thermal fields are investigated. It is found that the average Nusselt number as well as thermal hydraulic performance increases with increasing nanopartiles volume fraction and baffle height but accompanied by increases the pressure drop. The results also show that the best thermal- hydraulic performance is obtained at baffle height of 0.3 mm, locations of baffles at upper and lower walls of 10 and 15 mm, respectively, and nanoparticles volume fraction of 0.04 over the ranges of Reynolds number.
The present paper addresses the numerical study of non-Darcy laminar forced convectionflows in a pipe partially filled with grooved metallic foam attached in the inner pipe wall,which is subjected to a constant heat flux. Computations are carried out for nine differentdimensions of grooves with different Reynolds numbers namely; (250 ≤ Re ≤ 2000) andtheir influences on the fluid flow and heat transfer are discussed. The governing and energyequations are solved using the finite volume method (FVM) with temperature-dependentwater properties. The novelty of this work is developing of a new design for the metallicfoam, which has not studied previously yet. It is observed that the two helical grooves withtwo pitches increase the Nu around 5.23% and decrease the pumping power nearly 12%. Itis also showed a reduction in the amount of material required for manufacturing the heatexchanger, which leads to a decline in the weight of the system 8.29%.
In this paper, turbulent convective heat transfer in a triangular-ribbed chan-nel has been numerically investigated. SiO2-water with nanoparticles volume fraction of 4% and nanoparticles diameters of 30 nm is employed with Reyn-olds number ranging from 2000 to 8000. The governing continuity, momen-tum and energy equations in addition to low Reynolds number k-ε model have been transformed into body-fitted coordinates system and then solved using finite volume method. The effects of Reynolds number and rib heights on Nusselt number, pressure drop, thermal-hydraulic performance factor and entropy generation are presented and discussed. It is observed that the Nusselt number, pressure drop and thermal performance increase with in-creasing of Reynolds number and rib height. In addition, the highest perfor-mance factor can be obtained at Reynolds number of 6500 and rib height of 1.5 mm.