Asphaltene precipitation and deposition is a serious problem in many Iranian fields. The deposited asphaltene results in partial or total blockage of the wellbore and wellstring reducing or completely seizing oil production. This paper studies the asphaltene problem and mitigation methods in wellstring systematically. It presents new approach based on the combination of thermodynam...

Depending on the capillary number at play and the parameters of the flow geometry, a drop may or may not break when colliding with an obstacle in a microdevice. Modeling the flow of one-dimensional trains of monodisperse drops impacting a micro-obstacle, we show numerically that complex dynamics may arise through drop-to-drop hydrodynamic interactions: we observe sequences of breakup events in ...

We consider a holographic dual of hydrodynamics of N = 4 SYM plasma that undergoes non-isotropic three-dimensional expansion relevant to RHIC fireball. Our model is a natural extension of the Bjorken’s one-dimensional expansion, and it describes an elliptic flow whose v2 and eccentricity are given in terms of anisotropy parameters. Holographic renormalization shows that absence of conformal ano...

The decline of water quality in Tolo Harbour in recent years is an example of eutrophication. This paper delineates a robust unsteady two-layered, 2D finite difference numerical model for eutrophication in coastal waters. The modelling is based upon the numerically generated boundary-fitted orthogonal curvilinear grid system and integrated with a hydrodynamic model. It simulates the transport a...

The unsaturated soil hydraulic properties (the soil water characteristic and relative permeability curves) are key hydrodynamic parameters in the fields of soil science and civil engineering. Because of the strong dependency of these properties on water content, their determination is subject to considerable experimental and numerical problems. Difficulties increase when the soil approaches ove...

In this study combined heat and mass transfer by mixed convective flow along a moving vertical flat plate with hydrodynamic slip and thermal convective boundary condition is investigated. Using similarity variables, the governing nonlinear partial differential equations are converted into a system of coupled nonlinear ordinary differential equations. The transformed equations are then solved us...

Starting from a microscopic definition of an alignment vector proportional to the polarization, we discuss the hydrodynamics of polar liquid crystals with local C infinity v symmetry. The free energy for polar liquid crystals differs from that of nematic liquid crystals (D infinity h) in that it contains terms violating the n --> -n symmetry. First we show that these Z2-odd terms induce a gener...

the objective of this research is geometrical optimization of half toroidal continuously variable transmission (cvt) in order to achieve high power transmission efficiency and low weight. after dynamic analysis of the system, the contact between the disk and the roller is modeled according to elasto-hydrodynamic lubrication principles. accordingly, a computer model is created with geometric, th...

There is an increasing demand for knowledge about hydrodynamic, morphological and water quality processes within the estuarine waterways of the Gold Coast. This study describes the development of a suite of hydrodynamic, sediment transport and water quality models for the Gold Coast tidal waterways. The modeling framework described was developed to provide a strategic understanding of waterway ...

The first step in the dynamic modelling of pesticides is a reliable hydrodynamic model. SWAT (Soil and Water Assessment Tool) calculates both the dynamic hydrological response and the associated diffuse pesticide supply towards surface waters. In this study, we focus on the hydrodynamic part. First, an intensive data collection for the Nil-catchment was performed. During model set-up, a reducti...