Numerical simulation of the flow in pipes with numerical models

The objective of this study is to simulate the flow in pipes with various boundary conditions. Free-pressure fluid model, is used in the pipe based on Navier-Stokes equation. The models are solved by using the numerical method. A problem called stability of pipes is used in order to compare frequency and critical fluid velocity. When the initial conditions of problem satisfied the instability conditions, the free-pressure model could accurately predict discontinuities in the solution field. Employing nonlinear strains-displacements, stress-strain energy method the governing equations were derived using Hamilton's principal. Differential quadrature method (DQM) is used for obtaining the frequency and critical fluid velocity. The results of this paper are analyzed by hyperbolic numerical method. Results show that the level of numerical diffusion in the solution field and the range of well-posedness are two important criteria for selecting the two-fluid models. The solutions for predicting the flow variables is approximately equal to the two-pressure model 2. Therefore, the predicted pressure changes profile in the two-pressure model is more consistent with actual physics. Therefore, in numerical modeling of gas-liquid two-phase flows in the vertical pipe, the present model can be applied.

Automated summary

The objective of this study is to simulate flow in pipes with different boundary conditions. The flow is modeled using the free-pressure fluid model based on the Navier-Stokes equation, and numerical methods are used to solve the models. A problem called stability of pipes is used to compare frequency and critical fluid velocity. The results show that the level of numerical diffusion and the range of well-posedness are important criteria for selecting two-fluid models.