**Eldorado**

Resources for and from Research, Teaching and Studying

### Recent Submissions

The paper considers the inuence of thermal Maragoni convection on boundary layer flow of two-phase dusty fluid along a vertical wavy surface. The dimensionless boundary layer equations for two-phase problem are reduced to a convenient form by primitive variable transformation (PVF) and then integrated numerically by employing the implicit finite difference method along with the Thomas Algorithm. The effect of thermal Maragoni convection, dusty water and sinusoidal waveform are discussed in d...

This article is concerned with the class of solutions of gas boundary layer containing uniform, spherical solid particles over the surface of rotating axi-symmetric roundnosed body. By using the method of transformed coordinates, the boundary-layer equations for two-phase flow are mapped into a regular and stationary computational domain and then solved numerically by using implicit finite difference method. In this study, a rotating hemisphere is used as a particular example to elucidat...

The intent of this paper is to establish the detailed parametric study for laminar natural convection ow along a vertical wavy plate. Typical sinusoidal surface is used to elu- cidate the heat transport phenomena for the gas having variable thermophysical properties. From the present analysis, we will interrogate whether the presence of roughness element disturbs the gas ow and alter the physical characteristics associates with the wavy surface or not? The numerical solutions are obt...

The purpose of the present study is to establish the detailed parametric solutions for laminar natural convection flow of two-phase dusty fluid moving along a vertical wavy plate. Typical sinusoidal surface is used to elucidate the heat transport phenomena for the carrier gas having variable thermophysical properties. The governing equations are cast into a system of parabolic partial differential equations by using set of continuous transformations and then the resulting system is integ...

Process intensification of engineering applications in the framework of reacting flows in micromixer devices attracts the attention of engineers and scientists from various fields. With the steadily increasing available computational resources the traditional experimentally supported investigations may be extended by computational ones. For this purpose, a simulation framework based on state of the art numerical techniques extended with special grid deformation techniques has been develo...

An analysis is performed to study two-phase natural convection flow with heat transfer of nanofluid along a vertical way surface. The model includes equations expressing conservation of total mass, momentum and thermal energy for two-phase nano fluid. Primitive variable formulations (PVF) are used to transform the dimensionless boundary layer equations into convenient coordinate system and resulting equations are integrated numerically via implicit finite difference iterative scheme. The effe...

A comprehensive comparison of the Lagrangian and Eulerian frameworks for one-way coupled simulations of fiber suspension flows is performed for 2D and 3D models of orientation dynamics. An alternative approach to modeling the interactions of fibers is proposed for the Lagrangian framework. The presented methodology is based on the idea of the random walk, which is commonly used for modeling diffusion-like processes due to the Brownian motion of molecules. It is shown that a restriction of the...

The prime purpose of this analysis is to investigate the effect of variable thermophysical properties of nano fluid on bioconvection boundary layer flow past a uniformly heated vertical cone. The governing equations with associated boundary conditions for this phenomenon are cast into a non-dimensional form via continuous transformation, which are then solved by using the implicit finite difference method. How does the phenomena of heat transfer is effected due to the temperature-dependent th...

In this work, we present our numerical results of the application of Galerkin-based Isogeometric Analysis (IGA) to incompressible Navier-Stokes-Cahn-Hilliard (NSCH) equations in velocity-pressure-phase field-chemical potential formulation. For the approximation of the velocity and pressure fields, LBB compatible non-uniform rational B-spline spaces are used which can be regarded as smooth generalizations of Taylor-Hood pairs of finite element spaces. The one-step \theta-scheme is used for th...

This work extends the flux-corrected transport (FCT) methodology to arbitrary-order continuous finite element discretizations of scalar conservation laws on simplex meshes. Using Bernstein polynomials as local basis functions, we constrain the total variation of the numerical solution by imposing local discrete maximum principles on the Bézier net. The design of accuracy-preserving FCT schemes for high order Bernstein-Bézier finite elements requires the development of new algorithms and/o...

Es wurden verschiedene Themenkomplexe, wie Bildentrauschung und Visualisierung von Strömungen unter einem gemeinsamen Aspekt zusammengeführt: der Anwendung von partiellen Differentialgleichungen, finiten Elementen und modifizierten CFD-Programmen auf diese Probleme. Dabei wurden die Themen jeweils in eine ähnliche Richtung entwickelt, so dass der nichtlineare anisotrope Diffusions-Operator (NAD) in verschiedener Form zur Anwendung kam. Im Falle der Visualisierung von Strömungen allerdings in...

In this thesis we introduce a robust optimization approach which is based on a binary min-max-min problem. The so called Min-max-min Robust Optimization extends the classical min-max approach by calculating k different solutions instead of one. Usually in robust optimization we consider problems whose problem parameters can be uncertain. The basic idea is to define an uncertainty set U which contains all relevant problem parameters, called scenarios. The objective is then to calculate a solu...

In this work a set of efficient numerical methods for the simulation of particulate flows and virtual prototyping applications are proposed. These methods are implemented as modular components in the FEATFLOW software package which is used as the fluid flow solver. In direct particulate flow simulations the calculation of the hydrodynamic forces acting on the particles is of central importance. For this task acceleration techniques are proposed based on hierarchical spatial partitioning. For ...

Multiphase flow simulations benefit a variety of applications in science and engineering as for example in the dynamics of bubble swarms in heat exchangers and chemical reactors or in the prediction of the effects of droplet or bubble impacts in the design of turbomachinery systems. Despite all the progress in the modern computational fluid dynamics (CFD), such simulations still present formidable challenges both from numerical and computational cost point of view. Emerging as a powerful...

Die vorliegende Arbeit behandelt die Anwendung von Schoenbergs total positiven Funktionen, sowie exponentieller B-Splines in der Zeit-Frequenz-Analyse. Wir werden aufzeigen, dass sich diese Funktionen sehr gut als Fenster der Gabor-Transformation eignen und darüber hinaus anwendungsorientierte Algorithmen zur Implementierung angeben. Nach einer kurzen Einführung in die Thematik betrachten wir zunächst die Zak-Transformierten der genannten Funktionen und charakterisieren für eine Teilklasse ...

In various scientific fields problems appear, which can be solved by the optimal control theory. Optimal control problems can be found for example in fields like robotics, fluid mechanics and aeronautics. For modeling these phenomenas we of- ten use ordinary partial differential equations, so that the optimal control of the upcoming systems plays an important role in the optimization community. For describing the whole range of arising natural phenomenas also partial differential equations ar...