Diffusivity equation commonly used for pressure distribution prediction in porous media results from substituting equation of state and continuity equation in Navier-Stokes momentum equation. From mathematical point of view this equation format shows infinite propagation speed for pressure pulse through porous media, which is physically impossible. This issue may caused by numerous assumption...

Background 4D Phase-Contrast MRI ("4D Flow”) has become a choice modality for assessment of flow patterns in complex vasculatures, such as congenital heart diseases. For thoracic imaging, the technique relies on ECG-triggering and an imaging navigator to compensate for breathing motion [Markl-JMRI2007]. The acquisition of the navigator requires switching off the 4D flow acquisition, thus breaki...

The recognition and the calculation of all branches of solutions of the nonlinear boundary value problems is difficult obviously. The complexity of this issue goes back to the being nonlinearity of the problem. Regarding this matter, this paper considers steady state reactive transport model which does not have exact closed-form solution and discovers existence of dual or triple solutions in so...

Although two-phase flow is frequently encountered in various location of the process plants, there is no a general accepted and verified two-phase flow model that may be used to size lines for such conditions. An obvious example is condensate water return lines. The API method that used in this study is based on the homogeneous equilibrium flow assumption, that is, equal velocity and equal temp...