Showing 3 results for Pressure Drop
A. R. Azimian,
Volume 23, Issue 2 (1-2005)
Abstract
In this paper the laminar flow in the rectangular channel bends is simulated using numerical techniques. The turning angle of the channel bend and the area ratio of the channel cross-section are two important parameters to be examined. For flow simulation, the body fitted 3-D continuity and momentum equations are used and a body fitted general purpose code is developed. The existing results of a tied-diriven cavity and the experimental results from a 90 degree square bend were
used for code validation. After the code validation, the effect of the area change in the 90 degree bend is examined.
The numerical results indicated that increasing the area causes changes in the flow pattern, in turn, which has a direct impact on pressure drop. Similar results were obtained for other bend angles including 30, 60, 120, 150 and 180 degree bends. The results showed that increased bend turning angle increases the pressure drop which is in good agreement with existing experimental data.
E. Ebrahimnia-Bajestan, H. Niazmand,
Volume 36, Issue 1 (9-2017)
Abstract
In this paper, numerical simulation of flow and heat transfer of Al2O3/water nanofluid has been carried out through three different geometries involving a straight pipe, a 90o curved pipe and a 180o curved pipe under constant heat flux condition. Employing singe-phase model for the nanofluid, the Navier-Stokes and energy equations for an incompressible and laminar flow have been solved in a body fitted coordinate system using a homemade code based on control-volume approach, while all thermophysical properties of the nanofluid are dependent on considered temperature. The effects of different nanoparticle concentration and centrifugal forces on the temperature and pressure field have been examined in detail. The accordance of numerical results with experimental data expresses the accuracy of the employed numerical method for simulating flow and heat transfer in the curved pipes, as well as the accuracy of the single-phase model of the nanofluid. The Presented results indicated that both the nanoparticle and curvature effects improve the heat transfer characteristics dramatically, but at the expense of considerable increase in pressure drop. Furthermore, the results showed that in order to obtain the optimum operating conditions of nanofluids, different parameters such as heat transfer enhancement and pressure drop must be considered simultaneously. Finally, a method has been proposed to indicate the proper nanofluid and flow geometry for special practical applications.
H. Bazai, A. Azari, M. Moshtagh,
Volume 38, Issue 1 (8-2019)
Abstract
The purpose of this article is the numerical study of flow and heat transfer characteristics of Nanofluids inside a cylindrical microchannel with rectangular, triangular, and circular cross-sections. The size and shape of these sections have a significant impact on the thermal and hydraulic performance of the microchannel heat exchanger. The Nanofluids used in this work include water and De-Ethylene Glycol (DEG) as the base fluids and Al2O3, Cu, SiO2 and CuO as the nanoparticles. To solve the problem and extract the required data, a 3-D simulation was performed for the microchannel using ANSYS FLUENT 15.0 software and the effect of the cross-sectional shape of the fluid flow and the type of nanoparticles on the thermal transfer and fluid flow parameters was studied. From the obtained results, it can be observed that the addition of nanoparticles to the base fluid increases the heat transfer and pressure drop. The results also show that rectangular channels have the best performance among the three geometries examined as its heat transfer coefficient was 19.26% higher than the triangular cross section which had the worst performance.
