Nima Samkhaniani

Nima Samkhaniani
Karlsruhe Institute of Technology | KIT · Institute of Fluid Mechanics

PhD

About

32
Publications
15,659
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170
Citations
Introduction
At the moment I do a post-doc at KIT, and working on two sub-projects: 1- the contribution of house code OpenFOAM solver (phaseFieldFoam) for simulation of heat transfer during drop impact on a solid surface 2- numerical simulation of boiling in a microchannel using VOF method

Publications

Publications (32)
Article
In the present study, a new solver named phaseChangeHeatFoam is implemented on the OpenFOAM cfd package to simulate boiling and condensation. The solver is capturing the interface between two immiscible phases with a color function volume of fluid (CF-VOF) method. The two fluids (vapor and liquid) are assumed Newtonian and incompressible. The surfa...
Article
We extend a diffuse interface phase-field method for two-phase flow simulations so as to include interfacial heat transfer and the thermal Marangoni effect. The set of governing equations hold non-standard terms, which originally stem from the underlying variational consideration of the total free energy of the two-phase system. It consists of the...
Article
The interaction of droplets consisting of urea-water solution (UWS) with a wall is of interest for automotive exhaust gas after-treatment of Diesel engines by selective catalytic reduction (SCR). Since the impingement of tiny UWS droplets on the solid substrate is difficult to examine experimentally, little is known about the detailed dynamics of t...
Article
Full-text available
In this study, numerical approach for simulation of mold filling is presented. Polyurethane foam formation includes several complex phenomena such as chemical reactions, heat generation and blowing agent evaporation. Foam properties are variable during formation, foam viscosity increases and conductivity reduces. Foam phase is considered compressib...
Article
The bubble interactions with a wall affect many industrial application's performance. The single bubble rising in a stagnant fluid is studied next to an inclined wall. The two phases are incompressible, and the interface between phases is captured with the volume of fluid (VoF) method. The influence of various parameters such as wall slope (θ), con...
Article
Full-text available
The heat transfer of a single water droplet impacting on a heated hydrophobic surface is investigated numerically using a phase field method. The numerical results of the axisymmetric computations show good agreement with the dynamic spreading and subsequent bouncing of the drop observed in an experiment from literature. The influence of Weber numb...
Article
Phase-field methods based on the Cahn–Hilliard (CH) equation coupled to the incompressible Navier–Stokes equation are becoming increasingly popular for interface resolving numerical simulations of two-phase flows of immiscible fluids. One major limitation of this approach, however, is that the volume of each phase is not inherently preserved. This...
Article
Full-text available
The injection of urea-water solution (UWS) sprays into engine-close selective catalytic reduction (SCR) systems faces developers with complex challenges regarding two-phase flow and deposit formation. Potential spray impact on the static mixing elements inside the exhaust duct can lead to accumulation of liquid film and solid deposits, which may re...
Article
An accurate CFD modelling of wind flow around a city is important for a large variety of application. CFD simulations are heavily influenced by the large number of computational parameters defined in the model. This article presents a thorough and broad sensitivity study of the impact of computational parameters on the numerical outcome for wind fl...
Article
Full-text available
In present study, the rising of superheated vapor bubble in saturated liquid is simulated using volume of fluid method in OpenFOAM cfd package. The surface tension between vapor–liquid phases is considered using continuous surface force method. In order to reduce spurious current near interface, Lafaurie smoothing filter is applied to improve curva...
Conference Paper
Full-text available
Ancient wind catchers of Yazd city as net zero energy building components request the detailed numerical and experimental studies to renovate and reuse in old part of the city and for developing the new design strategies in future. In this ingenious natural ventilation strategy no other energy sources are required except wind and sun. In this resea...
Thesis
Full-text available
In the present simulation, a solver called phaseChangeHeatFoam is implemented under open source CFD code OpenFOAM to consider boiling and condensation. The solver is capturing interface among two immiscible phases using a color function volume of fluid. The two fluids (vapor and liquid) are assumed Newtonian and incompressible. The surface tension...
Article
In this paper, a direct numerical simulation of a two-phase incompressible gas–liquid flow for simulation of bubble motion and convective heat transfer in a microtube is presented. The microtube radius is 10 μm. The interface between the two phases is tracked by the volume of fluid method with the continuous surface force model. Newtonian flows are...
Article
Full-text available
In the present work, models that predict contact angle of droplet with solid surface are considered and compared. Two phases were assumed to be Newtonian, incompressible and immiscible fluids. OpenFOAM software is applied to simulate the two phases interface by using Color function VOF (CF-VOF) method. Different models for contact angle of droplet...
Conference Paper
Full-text available
Wind catchers (wind towers) are one component of the traditional sustainable buildings with a central courtyard in the hot regions of Iran. In this research a most common type of the wind tower – the four sided wind catcher-was evaluated both experimentally and numerically. The tower of the Mortaz house in the city center of Yazd was equipped with...
Article
Full-text available
n present study, the impact of single bubble on an inclined wall and its movement is investigated by applying volume of fluid method (VOF) in OpenFOAM open source cfd package using solver called interFoam. Both phases are incompressible and surface tension between the two phases is estimated by CSF method. The effect of some parameters such as cont...
Article
Full-text available
In this research two-phase slug flow regime in T-junction branching divider is examined in two regular and irregular groups. Simulation is accomplished by OpenFOAM open source software. Simulation uses single fluid with volume of fluid (VOF) method to follow gas-liquid two-phase flow interface. Constant velocity boundary condition for inlet, consta...
Book
It includes 10 chapters to cover different CFD applications from simple incompressible flow in duct to complex combustion reactions in chamber. It makes newbies familiar with numerical simulation of fluid flow and heat transfer using OpenFOAM. Extra information about book materials can be found in the following post at my website: http://openfoam.b...
Article
Full-text available
In the present study, volume of fluid method in Open FOAM open source CFD package will be extended to consider phase change phenomena due to condensation process. Both phases (liquid– vapor) are incompressible and immiscible. Vapor phase is assumed in saturated temperature. Interface between two phases is tracked with color function volume of fluid...
Article
Full-text available
One of the obstacles in simulation of two phase flow is parasite currents. These currents cause unphysical distortion at interface which impairs interface capturing and numerical results. In the present study, two methods (using Filter and s-CLSVOF) are implemented in OpenFOAM two phase flow solver called interFoam to reduce parasite current. Three...
Conference Paper
Full-text available
In the present study, volume of fluid method in OpenFOAM CFD package is extended to consider phase change phenomena due to heat transfer from solid region. Both fluid phases are considered immiscible and incompressible and mass transfer is accounted for Lee model. Newtonian flows are solved using a finite volume scheme based on PISO algorithm. This...
Article
Full-text available
In this paper, direct numerical simulation of two-phase incompressible gas-liquid flow for simulation of bubble motion in a microtube is presented. Microtube radius is 10 µm. The interface is tracked using volume of fluid (VOF) method with continuous surface force (CSF) model. The flow is solved using a finite volume scheme, based on PISO algorithm...
Conference Paper
Full-text available
In this paper, direct numerical simulation of incompressible two-phase (air-water) flow for simulation of bubble motion and convective heat transfer in micro tube is presented. Micro tube radius is 10 µm. The interface between two-phase is tracked with Volume of Fluid (VOF) method with Continuous Surface Force (CSF) model which is implemented in Op...
Conference Paper
Full-text available
In this study, Hardt evaporation model is implemented in OpenFOAM CFD package. Hardt evaporation model is suitable for phase change in micro size which the temperature of interface deviated from saturation temperature. Both phases are immiscible and incompressible and interface is resolving with VOF method. Newtonian flows are solved using a finite...
Conference Paper
Full-text available
In this paper, direct numerical simulation of two-phase incompressible gas-liquid flow is presented. The interface between two-phase is tracked with Volume of Fluid (VOF) method with Continuous Surface Force (CSF) model. Newtonian flows are solved using a finite volume scheme based on the Pressure Implicit with Splitting of Operators (PISO) algorit...

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