Papers by Keyword: Rectangular Cavity

Abstract: Throughout this study, the Lewis number influence on double-diffusive natural convection inside a rectangular cavity horizontally disposed, filled with Copper nanoparticles dispersed in water, heated and salted by constant thermal and solutal fluxes on the side walls while the horizontal ones are assumed thermally adiabatic and solutally impermeable, is studied analytically (parallel flow approximation) and numerically (finite difference method) for a large range of the aspect ratio, 1 ≤ A ≤ 16, the Lewis number, 10-3 ≤ Le ≤ 103, and the nanoparticles volume fractions, φ = 0 and 0.05. The results revealed that the numerical and analytical outcomes showed a good agreement. Both the aspect ratio and the Lewis number have a range responsible for variations in heat and mass transfer rates, A ≤ 12 and 10-2 ≤ Le ≤ 10 for Nusselt number and Le ≥ 10-2 for Sherwood number. The results obtained by examining the interest of using nanofluids in the considered configuration were against all expectations, that they led to a degradation of the rates of heat and mass transfers with the increase in the nanoparticle volume fraction.

Abstract: Numerical simulation of the motion of a viscous incompressible nonisothermal liquid in an open rectangular cavity with a glance of heterogeneity phase characteristics is performed. The hydrodynamic pattern of moving liquid has been obtained. Temperature profiles for solid and liquid phases have been received. The model parameters influence on the motion of the heat carrier and the distribution of temperatures in two phases have been studied.

Abstract: The paper presents the numerical research of conjugate heat exchange and hydrodynamics in the motion of viscous fluid in the technological elements of energy systems (cavities) in the consideration of its damage. The hydrodynamic figure of the motion viscous fluid and its temperature fields for solid and fluid phases obtained. The model parameters influence on the motion of the heat carrier and the distribution of temperatures in two phases have been studied. The impact of dynamic parameters and geometrical characteristics for the formation of contours generating craters studied.

Abstract: The end effects of symplectic direct solution to Stokes flow in a rectangular cavity are considered. Based on establishing the dual equations for Stokes flow in Hamilton system, the non-zero eigenvalues and their eigensolutions for an anti-symmetric problem were obtained. Expanding the solutions of dual equations by non-zero eigensolutions and determining the expansion coefficients by the end boundary conditions, the decay tendency and interaction mechanism of end effects were discussed and the end boundary errors were investigated. The resultant velocity caused by tangentially driving lid is gradually decayed along the longitudinal direction of cavity. The more number of the expansion items are superposed, the more accurate the solutions are. The smaller the depth-to-width ratios are, the stronger the interference between the end velocities is. The error of ends moving in the same directions is bigger than that in opposite directions.

Abstract: This paper for the first time explores the application of the meshless approach, structured on the Local Radial Basis Function Collocation Method (LRBFCM), for solving the freezing process with convection in the liquid phase for a metals-like material in a closed rectangular cavity. The enthalpy one-domain formulation is used to avoid inclusion of additional boundary conditions at the fluid-solid interface. To avoid numerical instabilities, the freezing of a pure substance is modeled by a narrow phase change interval. The fluid flow is solved by a local pressure-velocity coupling, based on the mass continuity violation [1-3], and the explicit time stepping is used to drive the system to the free boundary solution. The results are presented through temperature and streamfunction contours and the liquid-solid interface position at the steady state, as well as the time development of the average Nusselt number and the time development of the cavity average liquid fraction. Results are validated with already benchmarked melting example [3]. The paper represents first steps in solution of the Hebdich and Hunt experiment by an alternative numerical technique, different from the classical finite volume or finite element methods [4].