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- MakaleYalnız künye2023Scopus SJRQ3ENTROPY ANALYSIS OF HYBRID NANOFLUID FLOW OVER A ROTATING POROUS DISK: A MULTIVARIATE ANALYSIS
Prakash, J.; Tripathi, Dharmendra; Akkurt, Nevzat; Shedd, Tim
This article discusses the flow of a time-dependent biviscosity hybrid nanofluid boundary layer across a rotational permeable disk with effects of magnetic field and thermal radiation, and the subjective and quantitative transfer of heat flow. In the classic Von Karman issue, nanofluids comprising volume fractions ofAg-MgO/60% water and 40% ethylene glycol are considered instead of Newtonian regular fluids. The governing equations are transformed nonlinear ordinary differential equations using Von Karman transformations. The equation for the generation of entropy is calculated as a function of velocity and temperature gradient. This equation is made nondimensional by adding geometric and physical flow field-dependent parameters. The velocity profiles in the radial, tangential, and axial directions, as well as the axial pressure gradient, nanoparticle temperature distribution, local skin friction, Nusselt number, and Bejan number, are calculated by using MATLAB bvp4c. The multivariate analysis is implemented in the numerical results of the Nusselt number. A rotation parameter is generated by the spinning phenomena, which regulates the disk’s movement. Increasing the rotation of the disk causes fluid velocity to accelerate in both the radial and cross-radial directions, while contrasting phenomena can be noticed in the axial velocity of the flow. The temperature and wall shear stress of a nanofluid both rise with the disc’s Brinkman number and the volume fraction of nanoparticles. Increasing the thickness of the thermal boundary layer raises the axial pressure gradient. Entropy measured by the Bejan number Influences the magnetic field and the Biot number. Physical parameters presented in this article may be used to optimize the system’s performance. A magnetic rotating porous disk drives could be used in nuclear space propulsion engines and in heat transfer augmentation in thermal management and renewable energy sources.
AtıfScopus6WoS6OpenAlex6
İncele - MakaleYalnız künye2021Scopus SJRQ3Investigation of the effect of baffle cut on heat transfer and pressure drop in shell-and-tube heat exchangers using CFD
Işık, Erdem; Tuğan, Volkan
The shell-and-tube heat exchanger (STHE) is one of the most widely used types of heat exchangers in industry. For this reason, studies conducted to improve the performance of STHEs are of great importance. In this study, a single-shell- and double-tube-pass STHE was designed, and a three-dimensional and steady-state flow analysis of this heat exchanger was conducted using the CFD method. The purpose of the analysis was to investigate the effect of baffle cut and mass flow rate of the fluid on the shell side on heat transfer and pressure drop by using the ANSYS Fluent, which is a type of computational fluid dynamics (CFD) software. For this aim, oil and water are used as working fluids in the shell and tubes of the STHE, respectively. Four different mass flow rates (0.6 kg/s, 0.8 kg/s, 1.0 kg/s, and 1.2 kg/s) are used for the fluid in the shell. In the analysis, three different STHEs with baffle cuts of 20%, 30%, and 40% are compared. According to the results of the CFD analysis, baffle cut plays an important role in heat transfer and pressure drop. The highest heat transfer per pressure drop was achieved for the STHE with 40% baffle cut and the lowest was achieved for the STHE with 20% baffle cut.
AtıfScopus13WoS8OpenAlex11İncele - MakaleYalnız künye2021Scopus SJRQ3Comparison of heat transfer and condensation on the walls of buildings constructed with iron profiles versus other classic models
Kahraman, Gökhan
This study aims to present the evaluation of the thermal performance and the amount of condensation on the walls of a building with iron profiles under steady-state conditions. Elazig, situated in the east part of Turkey, was chosen for fieldwork. In this region, minimum average temperature is around 1°C during winter. Calculations are made in a real wall model and three different wall model scenarios. Estimated advantages and disadvantages of these have been investigated. Heat transfer and condensation amount are taken as variables. In four different building component models, the required amount of energy during the heating period is calculated month by month. Calculations reveal the resistance of the wall without application of insulation material with iron profile is higher than of the other three wall types. The wall built with betopen and iron profile saves 37.5% more energy than the wall with bricks. When the iron-profiled wall model is compared with the insulated brick wall, it is observed that energy savings are similar, but calculations show condensation begins on the iron profile wall. Iron profile buildings become popular increasingly in rural areas. As a result of this study, it is observed that iron profile buildings are advantageous in terms of energy saving compared to other building component models. However, condensation is inevitable in wall components of iron profile buildings and so the damage in the buildings is more than just a disadvantage, it is an irreversible result.
AtıfScopus2WoS3OpenAlex3İncele - DergiSpecial Topics and Reviews in Porous Media
- DergiHeat Transfer Research