Advanced Flow Modelling using Computational Fluid Dynamics (CFD)

Advanced Flow Modelling
Contents
Introduction:................................................................................................................................................................ 1
Analysis:....................................................................................................................................................................... 3
1. Preprocessing:..................................................................................................................................................... 4
2. Solving................................................................................................................................................................. 5
3. Post-processing....................................................................................................................................................6
Results:........................................................................................................................................................................ 6
Conclusion:................................................................................................................................................................ 18
References:................................................................................................................................................................ 19

Introduction:
Introduction to CFD:
CFD-Computational Fluid Dynamics is the study of the systems which includes Flow of fluid,
transfer of heat, chemical reactions, etc. with the help of computer-aided simulation. In general,
the problems which involve the fluid flow, heat transfer, chemical reactions, etc. are being solved
with the help of the Computers which are pre-installed with a proper CFD software Package.
(Olsen, J.E. and Johansen, S.T., 2015)
The software package consists of powerful tools in order to simulate, Analyze, Compute, and
Animate and execute the various input data’s. Some of the most utilized CFD package as of now
are Ansys Fluent, Solidworks simulate, Star CCM+, COMSOL Multiphysics, Ansys CFX,
Autodesk Simulation, Altair Acusolve, Xflow CFD, Simscale. These are the most used CFD
software packages as of now. The CFD packages greatly improve productivity, produces
efficient algorithms to solve a problem, accuracy in results, quick and accurate computation, etc.
Figure1. Illustrates the Flow Analysis done on a Centrifugal Pump with the help of a CFD software Package.
The computational fluid Dynamics works on the three basic fundamental principles they are:
Mass conservation principle, the second law of Newton or Naiver-Strokes equation, Energy
conservation principle or Bernoulli’s Equation. The CFD consists of many applications in
various fields such as Aeronautics in which the CFD is utilized to conduct a flow analysis on the
aerodynamics of aircrafts the various forces such as lift, drag, the coefficient of drag, etc. will be
calculated using the package. (D’Alessandro, V., et.al 2016)
The Automotive industries utilize the CFD package in order to conduct flow analysis on both the
internal and external parts such as flow analysis over the surface of an automobile, flow analysis
inside the automotive components such as a compressor, turbocharger, engine manifolds, etc. In
thermal power plants, it is utilized to conduct analysis on the turbines and other machines, heat

flow analysis etc. In HVAC the CFD plays a major role as the field is purely on the basis of the
flow of heat. Including this field, the CFD also has many wide varieties of applications.
In this study, the CFD package will be used to conduct a flow analysis over a couple of cylinders
which are confined in a particular space. The various steps involved in the computation will be
explained in further topics. ( Benitz, M.A., et.al 2016)
Figure2. Illustrates the velocity profile of air which is a result of flow analysis using CFD over a Motorcycle.
Analysis:
The task that is given in this module is to conduct a Flow Analysis over a couple of cylinders.
The Analysis will be carried out with the help of Ansys Fluent CFD package. The analysis is
separated into three parts such as:
1. Pre-processing
2. Solving
3. Post processing
The preprocessing phase involves the process of creation of a CAD model on which the Analysis
will be carried out and Meshing the created mode. The solving part includes the process of
setting up the boundary conditions, inlet and outlet conditions, fluid properties, analysis type,
computational requirements, etc. In this phase, the problem will be solved completely after
providing proper data. The final part is the post-processing in which the computed results will be
interpreted with the help of Ansys CFD post window. (Eswaran, M., et.al 2016)

Problem Definition:
The main objective of this task is to model and investigate the flow over a circular cylinder with
the help of Computational Fluid Dynamics. The model on which the study is to be conducted is
given in the Figure3. The final goal of this study is to get the velocity profile, pressure profile,
drag and lift forces which are acting on the circular cylinder when the fluid is allowed to pass
through the cylinders. The investigation is to be carried out for three different velocities.
Figure3. Illustrates the schematic of the computational domain
The study was carried out with the help of Ansys Fluent 16.0 CFD package. The various process
which was involved in this study is discussed below.
1. Preprocessing:
The Ansys Workbench is started and then the Ansys Fluent is selected. Which enables four tabs
as shown in the Figure. The given model on which the flow analysis to be conducted is Modeled
with the help of Design modeller this is the first step in
carrying out the study.
The Geometry tab is clicked which will further open the
Design modeller window. The design modeller window
consists of various CAD modelling tools which are used to
create, edit and manipulate models in 2D and 3D. The
required model in this particular is 2Dimensional. The
rectangle is created using the rectangle tools then the
dimensions are adjusted as per the given data. Then the
cylinders are created using circle tools as per the drawing.