Computational fluid dynamics improve efficiencies in fluid flow, heat and mass transfer processes. Computational Fluid Dynamics is a branch of fluid mechanics that uses numerical methods and algorithms to solve and analyze problems that involve fluid flows. Computational fluid dynamics Found Its self in various industrial applications, Biomedical, Electronics, Defense, Industrial,Environmental, Civil and drug delivery systems

1. dynamics- for chemical
reactor design
Article written and published
By
www.worldofchemicals.com

2. Abstract
 Computational fluid dynamics (CFD) is helping to generate
millions of dollars of savings in chemical process applications.
It gives process engineers a more complete understanding of
the internal operation of individual unit operations.
 As a result, some chemical and process companies are
equipping their engineers with CFD software and investing in
training to improve efficiencies in fluid flow, heat and mass
transfer processes.
 CFD uses computers to solve the fundamental nonlinear
differential equations that describe fluid flow (the Navier-
Stokes and allied equations) for predefined geometries with a
set of initial boundary conditions, process flow physics and
chemistry.
 Recent advances in CFD have made it possible to analyze
flow problems of ever-increasing complexity, including those
involving multiphase flows, mixing-related phenomena,
intricate equipment geometries and detailed chemically
reacting flows within process-relevant time scales.
 This article meant for explaining the future needs and
expectations of the chemical processing industry with respect

3. Introduction
 Computational Fluid Dynamics is a branch of
fluid mechanics that uses numerical methods
and algorithms to solve and analyze problems
that involve fluid flows. It is becoming a critical
part of the design process for more and more
companies. Computational
 Fluid Dynamics makes it possible to evaluate
velocity, pressure, temperature, and species
concentration of fluid flow throughout a solution
domain, allowing the design to be optimized prior
to the prototype phase.
 CFD modeling provides a good description of
flow field variables, velocities, temperatures, or a
mass concentration anywhere in the region with
details not usually available through physical
modeling. Once the basic model is
established, parametric runs can usually be

4. Introduction Cont ..
 CFD denotes collectively techniques solving equations
describing the physics of flows. It is the art of replacing such
Partial Differential Equation Systems by a set of algebraic
equations which can be solved using digital computers. CFD
became a research field in the late 1960s. First commercial
CFD software appeared in the 1980s including codes like
PHOENICS, FLUENT, STAR-CD, CFX, TASCFLOW, and
FLOW3D.
 It solves Euler, RANSE (Reynolds Averaged Navier-Stokes
Equations) or Navier-Stokes equations.
 Computational Fluid Dynamics provides a qualitative (and
sometimes even quantitative) prediction of fluid flows by
means of
 Mathematical modeling (partial differential equations)
 Numerical methods (discretization and solution techniques)
 Software tools (solvers, pre- and post processing utilities)
 Computational Fluid Dynamics enables scientists and
engineers to perform ‘numerical experiments’ (i.e. computer
simulations) in a ‘virtual flow laboratory’.

5. Reactor design
 Chemically reacting flows are those in which
the chemical composition, properties and
temperatures change as the result of a
simple or complex chain of reactions in the
fluid. The reactor is typically simulated using
a chemical-reaction model coupled with one
of the following four fluid-modeling
approaches
 1. A perfectly mixed stirred tank (either batch,
semibatch or continuous)
 2. A plug-flow reactor
 3. A network of a relatively small number of
perfectly mixed and plug-flow reactors
 4. A full CFD model.

6. Reactor design Cont ..
 The calculation time is relatively short for the first
three methods and such models may not assess
the effects of the reactor hydrodynamics on its
performance. Thermal nonuniformities may also
accelerate reaction processes, and, in some
cases, local hot spots may result in product
decomposition, or even in thermal runaways or
explosions.
 These nonuniformities cannot be captured when
modeling the reactor using simplified
hydrodynamics assumptions (such as perfect
mixing), but can be depicted with reasonable
accuracy using full CFD models.
 The chemical reactors which are architecture
through CFD fluid-flow pattern and temperature
fields can be calculated from conservation
equations for mass, momentum and enthalpy.

7. Blue Ridge Numerics, Inc Case
study
 Blue Ridge Numerics, Inc. has recently launched their
new CFdesign UVCalc Module, a CFD solution for
simulating and validating ultraviolet (UV) reactor
performance to ensure accurate fluence rates
(irradiances) for UV light disinfection.
 The use of germicidal UV light is a rapidly expanding
technology that is used to ensure public safety by
deactivating the DNA of bacteria, viruses, and other
pathogens, removing their ability to multiply and cause
disease.
 With the new partnership of Blue Ridge Numerics, Inc.
and Bolton Photosciences Inc., design engineers
developing UV applications for drinking water
disinfection, wastewater treatment, and manufacturing
processes for the food and beverage, medical device,
pharmaceutical, and semiconductors industries (among
others), can now easily leverage fluid flow and UV
calculation capabilities to speed up and optimize their
product development process.

8. Case study Cont …
 The Cfdesign UVCalc Module empowers engineers with
CAD-driven simulation tools that optimize product
performance during the digital design phase. The ability
to validate UV reactor performance for biodosimetry
testing, while still on the digital drawing board, is the
focus of Cfdesign and the UVCalc Module. Exploration
of multiple design scenarios before building prototypes
for physical testing equates to significant cost and time
savings.
 The use of UV light disinfection is rapidly expanding
around the world, especially in emerging countries like
China and India where infrastructure is aggressively
being developed to support population demands. As a
result, companies will be looking for cost effective
solutions to help more accurately design their products,
and UVCalc with Cfdesign is intended to meet that need
and more easily simulate and predict accurate reactor
performance

9. CFdesign UVCalc Module
Features
 Determine the distribution of UV dose along various
flow paths in the reactors and determine the impact of
other factors, such as the flow rate, flow
distribution, and axial mixing, all which can affect the
fluence or UV dose and the performance of the reactor.
 Run scenarios which include simulating the effect of
inlet flow distribution changes (piping), different
transmittance of the fluids, changes in flow rate or flow
obstructions.
 See side-by-side design comparison and data results of
multiple reactor concepts through contour plots, cut
planes, iso-surface, particle traces and vectors.
 Providing the ability to explore a broad spectrum of
possibilities to achieve an optimal design before
proceeding with the very expensive and time
consuming certification process.

10. Application areas
 Biomedical
 Electronics
 Defense
 Industrial
 Environmental
 Civil

11. Biomedical CFD Applications
 Flow modeling with computational fluid
dynamics (CFD) software lets you
visualize and predict physical
phenomena related to the flow of any
substance. It is widely used in
medical, pharmaceutical, and biomedical
applications to analyze
 Manufacturing Processes,
 Device Performance,
 Physiological Flows,
 Fluid-Structure Interactions,
 The Effectiveness of drug delivery
systems

12. Electronic CFD
Applications
 The Ansys' flagship CFD
software, ANSYS-FLUENT, as well as
the electronics industry custom-
designed ANSYS-ICEPAK suite, offer
high-performance electronics cooling
solutions covering a wide range of real
life problems on any level
 Component,
 Board,
 Package,
 System

13. Defense CFD Applications
 Ansys Computational Fluid Dynamics predict
how the toxins spread through space and
time, dam breaks, the collapse of storage
tanks and blast waves associated with
explosions or sudden gas leaks.
 It also plays a vital part in the design of
prevention systems, such as sensors,
detectors, portals, and screening devices, to
design personal protection equipment,
especially masks, suits, to assess the human
exposure levels near the attack site, such as
estimating the spread of particulates that
resulted from the collapse of the Twin Towers,
to plan fumigation procedures for buildings.

14. Industrial CFD Applications
 Ansys Computational Fluid Dynamics
software predicts fluid flow, heat
transfer, and chemical reactions, to
optimize, improve
equipment, processes and
plants, providing financial savings, for
processing of industrial minerals, the
recovery of precious stones, ore
treatment, polymer extrusion, film
casting, coating, fiber
spinning, thermoforming and blow
molding.

15. Environmental CFD
Applications
 Ansys Computational Fluid Dynamics
is used to design proposals, avoiding
the added costs of over sizing and
over specification, while reducing risk.
 Civil & Other CFD Applications
 Ansys Computational Fluid Dynamics
flow modeling solutions, you can
visualize the complex airflow and
thermal performance of data centers.

16. Conclusion
 CFD is already gaining importance in the industry. Some of the
companies reaping benefits of the technology are 3M; Air Products;
Argonne National Lab; Bechtel; BP Amoco; Chemineer ; Chevron;
Cray; Dow Chemical; Dow Corning; DuPont; Eastman Chemical; Eli
Lilly; Huntsman; LIGHTNIN; Mitsubishi Chemical-US; NETL ;Nalco
Chemical; Fuel Tech; National Institute of Standards & Technology;
Phillips Petroleum; Procter & Gamble; Rohm & Haas; Shell Oil-US;
UOP; Fuji Xerox Co., Ltd.
 The above companies have integrated CFD technology into their
design process, which leads to a shortened product-process
development cycle, optimization of existing processes, reduced
energy requirement, product cost and efficient design of new
products and processes. For instance, Fuji Xerox Co Ltd utilizes
computational fluid dynamics for designing branched exhaust ducts,
optimizing the volume of air suctioned in from each inlet of the
exhaust duct, to cool down, and collect dust inside the machine.
 Reviewing the chemical reactor design by CFD technology, it is
obvious that CFD can offer a great potential for the chemical
engineering processes.CFD is the combination of physics, flow
technology, computer applications, mathematics and mechanics. It
has already made a deep impact on chemical reaction engineering
due to its feasibility. Further, it is expected that the role of CFD in the
future design of chemical reactors will increase substantially and it w

17. Reference
 1] Franz Zdravistch and Ahmad Haidari, Virtual Fluid Dynamics, Available from-
http://www.chemicalprocessing.com/articles/2003/69.html?page=2
 [2] L. Oshinowo, L. Gunnewiek, K. Fraser, CFD in Autoclave Circuit Design, Hydrometallurgy
2003 - Proceedings of the 5th International Symposium; August 2003, Available from -
 http://www.hatch.ca/engineering/sead/cfd/articles/cfd_autoclave_circuit_design.htm
 [3] M. R. de Leval, MD, FRCSa, G. Dubini, PhDc, F. Migliavaccac, H. Jalali, MDa, G.
Camporinia, A. Redingtonb, R. Pietrabissa, PhD, Use of computational fluid dynamics in the
design of surgical procedures application to the study of competitive flows in cavopulmonary
connections, J Thorac Cardiovasc Surg 1996;111502-513, Available from -
http://jtcs.ctsnetjournals.org/cgi/content/abstract/111/3/502
 [4] C K Harris, D Roekaerts F J J Rosendal, F G J Buitendijk, Ph Daskopoulos, A J N
Vreenegoor, H Wang, Koninklijke Sheli-laboratorium, Computational Fluid Dynamics for
Chemical Reactor Engineering, Volume 51, Issue 10, Publisher Elsevier, Pages 1569-1594,
Available from- http://www.mendeley.com/research/computional-fluid-dynamics-chemical-
reactor-engineering/#
 [5] Ahmad H. HAIDARI and Brent MATTHEWS, Future trends for computational fluid dynamics
in the process industry, Third international conference on CFD in the mineral and process
industries,10-12 December 2003, Available from -
http://www.cfd.com.au/cfd_conf03/papers/114Hai.pdf
 [6] J.A.M Kuipers and W.P.M. van Swaaij, COMPUTATIONAL FLUID DYNAMICS to
CEHMICAL REACTION ENGINEERING, Available from -
http://doc.utwente.nl/12954/1/K301____.PDF
 http://www.worldofchemicals.com/11/chemistry-articles/computational-fluid-dynamics-
for-chemical-reactor-design.html
 Image Reference
 Fig. © From http://www.rdmag.com/Module-assists-CFD-for-UV-reactors/