The optimisation of MHD free convection inside porous trapezoidal cavity with the wavy bottom wall using response surface method

Multi-objective optimum design of porous triangular chamber using RSM

The present research focuses on experimental and numerical studies to evaluate how geometrical and operating parameters influence heat transfer of shell and coil heat exchangers The experiment was initially performed to verify the results of numerical analysis on a shell and single-coil (baseline coil) heat exchanger Numerical analysis was then conducted to determine the effect of changing the baseline coil to a new double coil configuration on heat transfer enhancement The results of the presented numerical study showed a good agreement with experimental results with an error rate of 46% In addition, the numerical simulation results were then conducted on a double coil and found that the Nusselt number in a double coil tube was 182% greater than that of a single-coil tube at 1800 Reynolds number shell side Based on the results, the two correlations were developed to predict the Nusselt numbers of shell and coil sides for wide ranges of Reynolds number (400

Experimental validation and numerical investigation for optimization and evaluation of heat transfer enhancement in double coil heat exchanger

\n The use of porous media (PM) to improve conductive heat transfer has been at the focus of interest in recent years. Limited studies, however, have focused on heat transfer in radial heat sinks (RHSs) fully and partially saturated porous media with a different arrangement. As a development of the above-mentioned investigations, this research, therefore, addresses the ability of radial porous heat sink solutions to improve the thermohydraulic characteristics and reduce the effect of the second thermodynamics law. The response surface methodology (RSM) technique with ansysfluent-cfd is utilized to optimize the thermohydraulic features and the total entropy generation by the multi-objective optimum design for different design parameters such as porosity (Ø), inlet temperature (Tin), and applied heat flux (Q) simultaneously after achieving the optimum porous media arrangement related to the flow direction. The results show that, in terms of the flow direction, the optimum radial porous heat sink of the 100%PM model is recognized as providing the best results and the best option (fully saturated porous media). Moreover, a significant agreement between the predicted and numerical simulation data for the optimum values is also seen. The optimum and undesirable designs of the thermohydraulic features, the total entropy generation, and the optimum thermal management are detected in this investigation.

The Thermohydraulic Characteristics and Optimization Study of Radial Porous Heat Sinks Using Multi-Objective Computational Method

Dispersion in coiled tubular reactors: A CFD and experimental analysis on the effect of pitch

Computational Fluid Dynamics Investigation of Pitch Variations on Helically Coiled Pipe in Laminar Flow Region

A computational fluid dynamics (CFD) study was conducted to analyse the flow structure and the effect of varying the coil pitch on the coil friction factor and wall shear stress, through utilising different models’ configurations. Three coils were tested, all of them having the same diameter and coil diameter: 0.005m and 0.04m respectively. Pitch variations began with 0.01, 0.05, 0.25 m for the first, second and third model respectively. Two turbulence models, STD(k-ϵ) and STD(k-w), were utilised in this simulation in order to determine the turbulence model which could capture most of the flow characteristics. A comparison was made between the STD(k-ϵ) and STD(k-w) models in order to analyse the pros and cons of each model. The results were validated with Ito’s equation for turbulent flow and compared with Filonenko’s equation for a straight pipe. The governing equations were discretized using finite volumes method and the SIMPLE algorithm was used to solve the equations iteratively. All the models were simulated using the ANSYS Fluent solver CFD commercial code. The results showed that in turbulent flows, Dean number had a stronger effect on reducing coil friction factor than the increment in pitch dimension.

/pdf/pitch-variations-study-on-helically-coiled-pipe-in-turbulent-4ha5sjo2ip.pdf

Pitch Variations Study on Helically Coiled Pipe in Turbulent Flow Region Using CFD

Received: 1 March 2020 Accepted: 28 May 2020 Experimental investigations of the flows inside helically coiled pipe are difficult and may also be expensive, particularly for small diameters. Computational fluid dynamics (CFD) packages, which can easily construct the geometry and change the dimensions with 100% of accuracy, provide an alternative solution for the experimental difficulties and uncertainties. Therefore, a computational fluid dynamics (CFD) study was conducted to analyse the flow structure and the effect of varying the coil pitch on the coil friction factor and wall shear stress, through utilising different models’ configurations. Three coils were tested, all of them sharing the same pipe and coil diameter: 0.005m and 0.04m respectively. Pitch variations began with 0.01, 0.05, 0.25 m for the first, second and third model respectively. In this study, the pressure drop was analysed, and the effects of this reduction on wall shear stress and coil friction factor were also examined using incompressible viscous laminar flow to elucidate the effect of varying coil pitch on the friction factor and wall shear stress. The results were validated by Ito’s equation for the laminar flow and compared with the Hagen-Poiseuille resistance formula for a straight pipe.

/pdf/investigate-the-effect-of-pitch-variations-on-helically-45jp90bznb.pdf

Anwer F. Faraj

Papers

Computational Fluid Dynamics Investigation of Pitch Variations on Helically Coiled Pipe in Laminar Flow Region

Pitch Variations Study on Helically Coiled Pipe in Turbulent Flow Region Using CFD

Investigate the Effect of Pitch Variations on Helically Coiled Pipe for Laminar Flow Region Using CFD