tailieunhanh - Computational Fluid Dynamics Harasek Part 6

Tham khảo tài liệu 'computational fluid dynamics harasek part 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 144 Computational Fluid Dynamics where h dh dr h d2h dr2. Then the gas core length with the consideration of the surface tension is calculated as 2 L 1SS2. fzd - . 18 g g 12nr pgr0 where W is the function of the Froude and Weber numbers. The improved CFD-based prediction methodology has been applied to the GE phenomena in the Monji s simple experiment conducted under the several fluid temperatures or surfactant coefficient concentrations. As a result the effect of the fluid property the dynamic viscosity and or surface tension coefficient was evaluated accurately by the improved CFD-based prediction methodology. 4. High-precision numerical simulation of interfacial flow General description of high-precision numerical simulation algorithm In order to reproduce the GE phenomena the authors have developed high-precision numerical simulation algorithms for gas-liquid two-phase flows. In the development two key issues are addressed for the simulation of the GE phenomena in FRs. One is the accurate geometrical modeling of the structural components in the gas-liquid two-phase flow which is important to simulate accurately vortical flows generated near the structural components. This issue is addressed by employing an unstructured mesh. The other issues is the accurate simulation of interfacial dynamics interfacial deformation which is addressed by developing an interface-tracking algorithm based on the high-precision volume-of-fluid algorithm on unstructured meshes Ito et al. 2007 . The physically appropriate formulations of momentum and pressure calculations near a gas-liquid interface are also derived to consider the physical mechanisms correctly in numerical simulations Ito Kunugi 2009 . Development of high-precision volume-of-fluid algorithm on unstructured meshes In this study a high-precision volume-of-fluid algorithm . the PLIC Piecewise Linear Interface Calculation algorithm Youngs 1982 is chosen as the interface-tracking algorithm owing to its high .