جستجوی مقالات مرتبط با کلیدواژه « pressure-based algorithm » در نشریات گروه « مکانیک »

The vapour absorption into the liquid falling film has occurred in various natural phenomena and its application has spread in various industries, such as the dehumidification and desalination industry. The complexity of flow dynamics, mass transfer, heat, and small dimensions of a liquid film has made its modeling and numerical simulation a key role in the investigation and studying of the effectiveness and improvement of the absorption process in a liquid film absorbent. In the present work, the effects of Reynolds number, wall temperature, and wall shape on the interfacial heat and mass transfer have been investigated. Numerical modeling has been performed using an unsteady Arbitrary Lagrangian-Eulerian interface tracking method by Fortran. The simulation results show that the deformation of the wall surface and the cooling of the wall temperature has a significant effect on the rate of gas vapor absorption into the laminar liquid film in comparison with the flat wall

When a shock wave propagates through a flow field that has nonlinear thermodynamic properties, different processes occur simultaneously. Wave compression, wave refraction, and vortex generation are examples of these processes that cause the waveform and thermodynamic properties of the fluid to change. The interaction of a shock wave with a cylindrical bubble is an example of a wave-bubble collision problem in which all of the above processes are observed. Due to the high computational cost of density-based algorithms in solving compressible interfacial flow problems such as shock wave interaction with the two-phase flow, using a fully coupled pressure-based algorithm is a good solution that will solve the problem with proper accuracy while reducing computation time. In this paper, using this algorithm, the interaction of the shock wave with the bubble is investigated; while validating the results, the effect of the computational grid size and the method of discretization of the governing equations are determined. It was observed that by increasing the number of computational grids according to the first-order upwind method, the simulation results become more accurate, and the numerical diffusion amount decreases. Also, by changing the discretization method to second-order upwind, the instabilities on the interface of the two phases increase due to spurious fluctuations, and the shape of the interface obtained from the numerical solution moves away from the experimental results.

In this study, a high-resolution scheme based on the WENO family has been developed in a pressure-based algorithm to prevent non-physical fluctuations based on Riemannian solver for steady and unsteady one dimensional and two dimensional compressible flows. The solution method is based on finite volume which uses an implicit solver with a structured collocated grid. Boundedness is applied by a high resolution essentially non-oscillatory scheme. To evaluate the numerical method, a shock tube containing shock wave, contact discontinuity and expansion waves has been considered, and the results obtained have been compared with the analytical results and the results based on the density based algorithm. The developed method is evaluated for lax configuration in two-dimensional inviscid flow. In addition, this method has been used to simulate two dimensional steady flow in a channel containing bump. The results show that the developed method is able to capture the physical and numerical discontinuities well.