Computational fluid dynamics (CFD) simulations were used to analyze natural ventilation and ventilative cooling in buildings. Reduced-scale experiments with particle image velocimetry (PIV) were conducted to validate the CFD models. The CFD simulations analyzed transitional indoor airflow and the effects of ventilation louver slat angle on air exchange efficiency and heat removal effectiveness.
CFD Analysis of Natural Convection Flow through Inclined EnclosureIJMERJOURNAL
ABSTRACT : The Natural convective laminar flow of two dimensional inclined rectangular enclosures is investigated by computational fluid dynamic analysis (fluent) in ansys.The upper and right wall keep adiabatic and other two walls are held in at different temperatures. The Rayleigh No varies from 103 to 106 to study the natural convection. The effect of inclination angle of the square and rectangle cavity on natural convection flow is studied for each combination of Rayleigh No. The effect of stream function and temperature contour show similar properties at low Rayleigh No. and it goes increases and show different pattern at high Rayleigh No
DSD-INT 2017 Delft3D FM - validation of hydrodynamics (1D,2D,3D) - van DamDeltares
Presentation by Arthur van Dam, Deltares, Netherlands, at the Delft3D - User Days (Day 1: Hydrodynamics), during Delft Software Days - Edition 2017. Monday, 30 October 2017, Delft.
Coarse CFD-DEM simulation of Rare Earth Element leaching reactor, FCC re-gen...Liqiang Lu
In past decades, the continuum approach was the only practical technique to simulate large-scale fluidized bed reactors because discrete approaches suffer from the cost of tracking huge numbers of particles and their collisions[1,. This study significantly improved the computation speed of discrete particle methods in two steps: First, the time-driven hard-sphere (TDHS) algorithm with a larger time-step is proposed allowing a speedup of 20-60 times; second, the number of tracked particles is reduced by adopting the coarse-graining technique gaining an additional 2-3 orders of magnitude speedup of the simulations. A new velocity correction term was introduced and validated in TDHS to solve the over-packing issue in dense granular flow. The TDHS was then coupled with the coarse-graining technique to simulate the heat transfer and chemical reaction mechanisms in an industrial FCC regenerator in a reasonable time with little computational resources. The simulation results compared well with available industrial data and proved that this new approach can be used for efficient and reliable simulations of industrial-scale fluidized bed systems.
References:
1. Lu, L., Liu, X., Li, T., Wang, L., Ge, W., Benyahia, S., 2017. Assessing the capability of continuum and discrete particle methods to simulate gas-solids flow using DNS predictions as a benchmark. Powder Technology 321, 301-309.
2. Lu, L.; Gopalan, B.; Benyahia, S., 2017. Assessment of different discrete particle methods ability to predict gas-particle flow in a small-scale fluidized bed. Industrial & Engineering Chemistry Research, 56, 7865–7876
3. Lu, L., Benyahia, S., Li, T., 2017. An efficient and reliable predictive method for fluidized bed simulation. AIChE Journal 63, 5320-5334.
4. Lu, L.; Konan, A.; Benyahia, S., 2017. Influence of grid resolution, parcel size and drag models on bubbling fluidized bed simulation. Chemical Engineering Journal, 326, 627-639.
5. Lu, L.; Morris, A.; Li, T.; Benyahia, S., 2017. Extension of a coarse grained particle method to simulate heat transfer in fluidized beds. Int. J. Heat Mass Transfer, 111, 723-735.
6. Lu, L., Yoo, K., Benyahia, S., 2016. Coarse-Grained-Particle Method for Simulation of Liquid–Solids Reacting Flows. Industrial & Engineering Chemistry Research 55, 10477-10491.
7. Lu, L., Xu, J., Ge, W., Gao, G., Jiang, Y., Zhao, M., Liu, X., Li, J., 2016. Computer virtual experiment on fluidized beds using a coarse-grained discrete particle method—EMMS-DPM. Chemical Engineering Science 155, 314-337.
8. Lu, L., Xu, J., Ge, W., Yue, Y., Liu, X., Li, J., 2014. EMMS-based discrete particle method (EMMS–DPM) for simulation of gas–solid flows. Chemical Engineering Science 120, 67-87.
CFD Analysis of Natural Convection Flow through Inclined EnclosureIJMERJOURNAL
ABSTRACT : The Natural convective laminar flow of two dimensional inclined rectangular enclosures is investigated by computational fluid dynamic analysis (fluent) in ansys.The upper and right wall keep adiabatic and other two walls are held in at different temperatures. The Rayleigh No varies from 103 to 106 to study the natural convection. The effect of inclination angle of the square and rectangle cavity on natural convection flow is studied for each combination of Rayleigh No. The effect of stream function and temperature contour show similar properties at low Rayleigh No. and it goes increases and show different pattern at high Rayleigh No
DSD-INT 2017 Delft3D FM - validation of hydrodynamics (1D,2D,3D) - van DamDeltares
Presentation by Arthur van Dam, Deltares, Netherlands, at the Delft3D - User Days (Day 1: Hydrodynamics), during Delft Software Days - Edition 2017. Monday, 30 October 2017, Delft.
Coarse CFD-DEM simulation of Rare Earth Element leaching reactor, FCC re-gen...Liqiang Lu
In past decades, the continuum approach was the only practical technique to simulate large-scale fluidized bed reactors because discrete approaches suffer from the cost of tracking huge numbers of particles and their collisions[1,. This study significantly improved the computation speed of discrete particle methods in two steps: First, the time-driven hard-sphere (TDHS) algorithm with a larger time-step is proposed allowing a speedup of 20-60 times; second, the number of tracked particles is reduced by adopting the coarse-graining technique gaining an additional 2-3 orders of magnitude speedup of the simulations. A new velocity correction term was introduced and validated in TDHS to solve the over-packing issue in dense granular flow. The TDHS was then coupled with the coarse-graining technique to simulate the heat transfer and chemical reaction mechanisms in an industrial FCC regenerator in a reasonable time with little computational resources. The simulation results compared well with available industrial data and proved that this new approach can be used for efficient and reliable simulations of industrial-scale fluidized bed systems.
References:
1. Lu, L., Liu, X., Li, T., Wang, L., Ge, W., Benyahia, S., 2017. Assessing the capability of continuum and discrete particle methods to simulate gas-solids flow using DNS predictions as a benchmark. Powder Technology 321, 301-309.
2. Lu, L.; Gopalan, B.; Benyahia, S., 2017. Assessment of different discrete particle methods ability to predict gas-particle flow in a small-scale fluidized bed. Industrial & Engineering Chemistry Research, 56, 7865–7876
3. Lu, L., Benyahia, S., Li, T., 2017. An efficient and reliable predictive method for fluidized bed simulation. AIChE Journal 63, 5320-5334.
4. Lu, L.; Konan, A.; Benyahia, S., 2017. Influence of grid resolution, parcel size and drag models on bubbling fluidized bed simulation. Chemical Engineering Journal, 326, 627-639.
5. Lu, L.; Morris, A.; Li, T.; Benyahia, S., 2017. Extension of a coarse grained particle method to simulate heat transfer in fluidized beds. Int. J. Heat Mass Transfer, 111, 723-735.
6. Lu, L., Yoo, K., Benyahia, S., 2016. Coarse-Grained-Particle Method for Simulation of Liquid–Solids Reacting Flows. Industrial & Engineering Chemistry Research 55, 10477-10491.
7. Lu, L., Xu, J., Ge, W., Gao, G., Jiang, Y., Zhao, M., Liu, X., Li, J., 2016. Computer virtual experiment on fluidized beds using a coarse-grained discrete particle method—EMMS-DPM. Chemical Engineering Science 155, 314-337.
8. Lu, L., Xu, J., Ge, W., Yue, Y., Liu, X., Li, J., 2014. EMMS-based discrete particle method (EMMS–DPM) for simulation of gas–solid flows. Chemical Engineering Science 120, 67-87.
Numerical Investigation of Mixed Convective Flow inside a Straight Pipe and B...iosrjce
The present study deals with a numerical investigation of steady laminar and turbulent mixed
convection heat transfer in a horizontal pipe and bend pipe using air as the working fluid.The thermal boundary
condition chosen is that of uniform temperature at the outer wall. Computations were performed to investigate
the effect of inlet Rayleigh number and Reynolds number in the velocity and temperature profile at inside of the
pipe. The secondary flow is more intense in the upper part of the cross-section. It increases throughout the
cross-section until its intensity reaches a maximum, and then it becomes weak at far downstream. For the
horizontal pipe the value of the L/D ratio becomes more than 10 the secondary flow effects are neutralized and
the velocity profile almost become constant throughout.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Experimental Investigation on Heat Transfer Analysis in a Cross flow Heat Ex...IJMER
Heat exchanger is devices used to exchange the heat between two liquids that are at different
temperature .These are used as a reheated in many industries and auto mobile sector and power
plants. The main aim of our project is thermal analysis of heat exchanger with waved baffles for
different types of materials at different mass flow rates and different tube diameters using FLOEFD
software and comparing the results that are obtained. The work is a simplified model for the study of
thermal analysis of shell-and-tubes heat exchangers having water as cold and hot fluid. Shell and
Tube heat exchangers are having special importance in boilers, oil coolers, condensers, pre-heaters.
They are also widely used in process applications as well as the refrigeration and air conditioning
industry. The robustness and medium weighted shape of Shell and Tube heat exchangers make them
well suited for high pressure operations. The project shows the best material, best boundary conditions
and parameters of materials we have to use for better heat conduction. For this we are chosen a
practical problem of counter flow shell and tube heat exchanger having water, by using the data that
come from cfd analysis. A design of sample model of shell and tube heat exchanger with waved baffles
is using Pro-e and done the thermal analysis by using FLOEFD software by assigning different
materials to tubes with different diameters having different mass flow rates and comparing the result
that obtained from FLOEFD software.
Lab 2 Fluid Flow Rate.pdf
MEE 491 Lab #2: Fluid Flow Rate
The goal of the fluid flow lab is to become familiar with measuring fluid pressure and flow rate
with orifice obstruction meters.
Reading: Beckwith pgs 489-576
Moran, Shapiro, Munson, and Dewitt (i.e. your thermofluids book): Ch 11, 12 & 14
Introduction
This experiment introduces you to orifice obstruction meters, which are a common tool used
to measure fluid flow rate. The experimental system includes two types of orifice obstruction
meters: flow nozzles and orifice plates. The differential pressure across the orifice obstruction
meter is needed to calculate flow rate, and so pressure measuring devices are included to
measure a) the differential pressure across the flow nozzle and b) the differential pressure across
the orifice plate. Figure 1 illustrates the experimental system and its relevant components.
Air from the room enters the plenum chamber through the nozzle. The air then flows through
flexible black tubing and into a transparent circular duct that is instrumented with the orifice
plate. Lastly the air flow enters the vacuum pump via more flexible black tubing and is returned
to the room via the vacuum pumps outlet. Variable air flow through the system can be achieved
by a rheostat knob that controls the vacuum pump. We will assume that any leaks in the system
are negligible. Since the obstruction meters are connected in series, both obstruction meters
measure the same mass flow rate (i.e. conservation of mass).
In the case of the flow nozzles, two different sizes are provided. Both nozzles are
standardized ASME long-radius flow nozzles with diameters of 1.265 cm and 2.530 cm for the
small and medium nozzles, respectively. The orifice plate has a diameter of 0.795 in and is
located in a pipe with a diameter of 2 in.
Figure 1. Photograph of the experimental system and relevant components for
part A of this lab
The discharge coefficient, CD, is a very important performance parameter for an orifice
obstruction meter. The discharge coefficient tells you the ratio of the actual orifice flow rate,
Qactual, to the ideal orifice flow rate, Qideal:
𝐶! =
!!"#$!%
!!"#$%
[1]
The ideal flow rate corresponds to the flow rate as derived from Bernoulli’s equation. Two of
the assumptions that Bernoulli’s equation makes are isentropic and incompressible flow. While
these are good approximations in many engineering situations, no real system is every truly
isentropic and incompressible. Hence the discharge coefficient is always less than 1. In this lab
you will determine the discharge coefficient for the nozzles as well as the orifice plate.
Procedure
• With the small nozzle measure at five different steady-state (i.e. make sure pressures are
not changing with time) flow rates measure:
o The differential pressure across the flow nozzle.
o The differential pressure across the orifice plate wi ..
Amplitude Effects on Natural Convection in a Porous Enclosure having a Vertic...IOSR Journals
Numerical investigation of unsteady natural convection flow through a fluid-saturated porous
medium in a cubic enclosure which is induced by time-periodic variations in the surface temperature of a
vertical wall was considered. The governing equations were written under the assumption of Darcy-law and
then solved numerically using finite difference method. The problem is analyzed for different values of
amplitude a in the range 0.2 ≤ a ≤ 0.8, the Rayleigh number, Ra=200, Period, τ = 0.01, time, 0 ≤ t ≤ 0.024. It
was found that heat transfer increases with increasing the amplitude. The location of the maximum fluid
temperature moves with time according to the periodically changing heated wall temperature. Two main cells
rotating in opposite direction to each other were observed in the cavity for all values of the parameters
considered. The amplitude of Nusselt number increases with the increase in the oscillating amplitude. All the
results of the problem were presented in graphical form and discussed.
Paul J. Boudreaux Consider a Mixed Analog/Digital/MEMsssusercf6d0e
Heat spreaders with high K values attached to the chip can help alleviate lateral DT problems. Placing the system or components into a forced isothermal environment also reduces DT, dT/dt and CTE related problems. Severing the thermomechanical heat path reduces or eliminates shock and vibration from entering the system while reducing weight.
Numerical Investigation of Mixed Convective Flow inside a Straight Pipe and B...iosrjce
The present study deals with a numerical investigation of steady laminar and turbulent mixed
convection heat transfer in a horizontal pipe and bend pipe using air as the working fluid.The thermal boundary
condition chosen is that of uniform temperature at the outer wall. Computations were performed to investigate
the effect of inlet Rayleigh number and Reynolds number in the velocity and temperature profile at inside of the
pipe. The secondary flow is more intense in the upper part of the cross-section. It increases throughout the
cross-section until its intensity reaches a maximum, and then it becomes weak at far downstream. For the
horizontal pipe the value of the L/D ratio becomes more than 10 the secondary flow effects are neutralized and
the velocity profile almost become constant throughout.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Experimental Investigation on Heat Transfer Analysis in a Cross flow Heat Ex...IJMER
Heat exchanger is devices used to exchange the heat between two liquids that are at different
temperature .These are used as a reheated in many industries and auto mobile sector and power
plants. The main aim of our project is thermal analysis of heat exchanger with waved baffles for
different types of materials at different mass flow rates and different tube diameters using FLOEFD
software and comparing the results that are obtained. The work is a simplified model for the study of
thermal analysis of shell-and-tubes heat exchangers having water as cold and hot fluid. Shell and
Tube heat exchangers are having special importance in boilers, oil coolers, condensers, pre-heaters.
They are also widely used in process applications as well as the refrigeration and air conditioning
industry. The robustness and medium weighted shape of Shell and Tube heat exchangers make them
well suited for high pressure operations. The project shows the best material, best boundary conditions
and parameters of materials we have to use for better heat conduction. For this we are chosen a
practical problem of counter flow shell and tube heat exchanger having water, by using the data that
come from cfd analysis. A design of sample model of shell and tube heat exchanger with waved baffles
is using Pro-e and done the thermal analysis by using FLOEFD software by assigning different
materials to tubes with different diameters having different mass flow rates and comparing the result
that obtained from FLOEFD software.
Lab 2 Fluid Flow Rate.pdf
MEE 491 Lab #2: Fluid Flow Rate
The goal of the fluid flow lab is to become familiar with measuring fluid pressure and flow rate
with orifice obstruction meters.
Reading: Beckwith pgs 489-576
Moran, Shapiro, Munson, and Dewitt (i.e. your thermofluids book): Ch 11, 12 & 14
Introduction
This experiment introduces you to orifice obstruction meters, which are a common tool used
to measure fluid flow rate. The experimental system includes two types of orifice obstruction
meters: flow nozzles and orifice plates. The differential pressure across the orifice obstruction
meter is needed to calculate flow rate, and so pressure measuring devices are included to
measure a) the differential pressure across the flow nozzle and b) the differential pressure across
the orifice plate. Figure 1 illustrates the experimental system and its relevant components.
Air from the room enters the plenum chamber through the nozzle. The air then flows through
flexible black tubing and into a transparent circular duct that is instrumented with the orifice
plate. Lastly the air flow enters the vacuum pump via more flexible black tubing and is returned
to the room via the vacuum pumps outlet. Variable air flow through the system can be achieved
by a rheostat knob that controls the vacuum pump. We will assume that any leaks in the system
are negligible. Since the obstruction meters are connected in series, both obstruction meters
measure the same mass flow rate (i.e. conservation of mass).
In the case of the flow nozzles, two different sizes are provided. Both nozzles are
standardized ASME long-radius flow nozzles with diameters of 1.265 cm and 2.530 cm for the
small and medium nozzles, respectively. The orifice plate has a diameter of 0.795 in and is
located in a pipe with a diameter of 2 in.
Figure 1. Photograph of the experimental system and relevant components for
part A of this lab
The discharge coefficient, CD, is a very important performance parameter for an orifice
obstruction meter. The discharge coefficient tells you the ratio of the actual orifice flow rate,
Qactual, to the ideal orifice flow rate, Qideal:
𝐶! =
!!"#$!%
!!"#$%
[1]
The ideal flow rate corresponds to the flow rate as derived from Bernoulli’s equation. Two of
the assumptions that Bernoulli’s equation makes are isentropic and incompressible flow. While
these are good approximations in many engineering situations, no real system is every truly
isentropic and incompressible. Hence the discharge coefficient is always less than 1. In this lab
you will determine the discharge coefficient for the nozzles as well as the orifice plate.
Procedure
• With the small nozzle measure at five different steady-state (i.e. make sure pressures are
not changing with time) flow rates measure:
o The differential pressure across the flow nozzle.
o The differential pressure across the orifice plate wi ..
Amplitude Effects on Natural Convection in a Porous Enclosure having a Vertic...IOSR Journals
Numerical investigation of unsteady natural convection flow through a fluid-saturated porous
medium in a cubic enclosure which is induced by time-periodic variations in the surface temperature of a
vertical wall was considered. The governing equations were written under the assumption of Darcy-law and
then solved numerically using finite difference method. The problem is analyzed for different values of
amplitude a in the range 0.2 ≤ a ≤ 0.8, the Rayleigh number, Ra=200, Period, τ = 0.01, time, 0 ≤ t ≤ 0.024. It
was found that heat transfer increases with increasing the amplitude. The location of the maximum fluid
temperature moves with time according to the periodically changing heated wall temperature. Two main cells
rotating in opposite direction to each other were observed in the cavity for all values of the parameters
considered. The amplitude of Nusselt number increases with the increase in the oscillating amplitude. All the
results of the problem were presented in graphical form and discussed.
Paul J. Boudreaux Consider a Mixed Analog/Digital/MEMsssusercf6d0e
Heat spreaders with high K values attached to the chip can help alleviate lateral DT problems. Placing the system or components into a forced isothermal environment also reduces DT, dT/dt and CTE related problems. Severing the thermomechanical heat path reduces or eliminates shock and vibration from entering the system while reducing weight.
Apart from TDMA, there are other iterative methods for solving the
system of equations which are faster. Unlike TDMA, which solves
the problem line by line, these iterative methods solves all
equations simultaneously. As a result these methods are faster than
TDMA. Some of the fast iterative methods are
1) SIP (strongly implicit procedure)
2) MSIP (modified SIP)
3) CG (Conjugate gradient method)
4) BiCGSTAB (bi-conjugate gradient stabilized method)
CG method is used for solving linear systems of equations which
have a symmetric coefficient matrix. All other methods mentioned
above are used for systems of equations involving non-symmetric
coefficient matrices.
must be set up at each nodal point.
We obtain a system of linear algebraic equations
Solve the system for values
Use any matrix solution method.
e.g. Tri-diagonal matrix algorithm (see textbook)
or: Gauss Seidel iteration method.
The convection of a scalar variable depends on the
magnitude and direction of the local velocity field.
How to find flow field?
Momentum equations can be derived from the Both sides of the equation contains temperatures at the new time step,
and a system of algebraic equations must be solved at each time level
is unconditionally stable for any Δt
is only first order accurate in time
small time steps are needed to ensure accuracy of results
The understanding of two-phase flow and heat transfer
with phase change in minichannels is needed for the design and
optimization of heat exchangers and other industrial
applications. In this study a three-dimensional numerical model
has been developed to predict filmwise condensation heat
transfer inside a rectangular minichannel. The Volume of Fluid
(VOF) method is used to track the vapor-liquid interface. The
modified High Resolution Interface Capture (HRIC) scheme is
employed to keep the interface sharp. The governing equations
and the VOF equation with relevant source terms for
condensation are solved. The surface tension is taken into
account in the modeling and it is evaluated by the Continuum
Surface Force (CSF) approach. The simulation is performed
using the CFD software package, ANSYS FLUENT, and an inhouse
developed code. This in-house code is specifically
developed to calculate the source terms associated with phase
change. These terms are deduced from Hertz-Knudsen equation
based on the kinetic gas theory. The numerical results are
validated with data obtained from the open literature. The
standard k-ω model is applied to model the turbulence through
both the liquid and vapor phase. The numerical results show
that surface tension plays an important role in the condensation
heat transfer process. Heat transfer enhancement is obtained
due to the presence of the corners. The surface tension pulls the
liquid towards the corners and reduces the average thermal
resistance in the cross section.
The role of boilers and heat recovery steam generators (HRSGs) in the industrial
economy has been profound. Boilers form the backbone of power plants,
cogeneration systems, and combined cycle plants. There are few process
plants, refineries, chemical plants, or electric utilities that do not have a steam
plant. Steam is the most convenient working fluid for industrial processing,
heating, chilling, and power generation applications. Fossil fuels will continue to
be the dominant energy providers for years to come.
This book is about steam generators, HRSGs, and related systems. There
are several excellent books on steam generation and boilers, and each has been
successful in emphasizing certain aspects of boilers and related topics such as
mechanical design details, metallurgy, corrosion, constructional aspects, maintenance,
or operational issues. This book is aimed at providing a different
perspective on steam generators and is biased toward thermal and process
design aspects of package boilers and HRSGs. (The terms ‘‘waste heat boiler’’
and ‘‘HRSG’’ are used in the same context.) My emphasis on thermal engineering
aspects of steam generators reinforced by hundreds of worked-out real-life
examples pertaining to boilers, HRSGs, and related systems will be of interest
to engineers involved in a broad field of steam generator–related activities such as
consulting, design, performance evaluation, and operation. During the last three decades I have had the opportunity to design hundreds
of package boilers and several hundred waste heat boilers that are in operation in
the U.S. and abroad. Based on my experience in reviewing numerous specifications
of boilers and HRSGs, I feel that consultants, plant engineers, contractors,
and decision makers involved in planning and developing steam plants often do
not appreciate some of the important and subtle aspects of design and performance
of steam generators.
Among the leading causes of discomfort in an air conditioned environment we can detected:
• too high air flow, generating drafts;
• uneven distribution of the incoming air volume;
• non homogeneous temperature distribution in the room.
To avoid these drawbacks, it is necessary to generate a proper diffusion of the air, which guarantees the right
temperature, relative humidity, speed and purity corresponding to the environmental comfort desired.
The Eurapo UCS cassette units are able to give a balanced response to all these needs: the outlet air is spread
like a classic four-way ceiling diffuser, with distribution from two to four orthogonal directions.
This system takes full advantage of the Coanda effect, greatly reducing the air flow direct to people, with
positive consequences for their comfort.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
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Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
2. PAGE 2
Contents
1. CFD: what and why?
2. Natural ventilation: indoor airflow
o Computational Fluid Dynamics simulations (+ experiments)
3. Natural ventilation: ventilative cooling
o Computational Fluid Dynamics simulations
4. Natural ventilation: stadium study
o Computational Fluid Dynamics simulations (+ experiments)
5. Closing remarks
3. PAGE 3
CFD: what and why?
• What:
o CFD = Computational fluid dynamics
o CFD is “solving fluid flow problems numerically”
o "CFD is the art of replacing the integrals or the partial derivatives
(as the case may be) in the Navier-Stokes equations by
discretized algebraic forms, which in turn are solved to obtain
numbers for the flow field values at discrete points in time and/or
space.”
(John D. Anderson, Jr. 1995).
o Computational Fluid Dynamics is a tool that allows us to solve
flow problems that do not have known analytical solutions and
cannot be solved in any other way.
4. PAGE 4
CFD: what and why?
• Why:
o Understanding & interpreting (“numerical experiments” to provide
information if experiments are not possible, or in addition to
experiments)
o Designing (“future objects” on which experiments are not yet
possible, simply because they do not yet exist)
5. PAGE 5
CFD: what and why?
• Advantages
o Relatively inexpensive and fast (computational costs decrease as a function
of time)
o CFD provides “complete” information (all relevant variables in the whole
domain)
o Easily allows parametric studies (= important in design)
o No similarity constraints (simulations can be performed at full scale)
o Allows numerical experiments (e.g. study of explosions, failures, … which
you do not want to reproduce in reality)
• Disadvantages
o Accuracy and reliability are major concerns
o Results are very sensitive to large number of parameters to be set by the user
o Verification and validation are imperative (and validation requires
experiments)
6. PAGE 6
• Modeling approach: RANS vs. LES
o Reynolds-averaged Navier-Stokes: time-averaged
solution.
• Mean flow is ‘solved’, all eddies are ‘modeled’.
o Large Eddy Simulation: time-dependent solution.
• Large eddies are ‘solved’, smaller eddies are ‘modeled’.
• More accurate, but computationally far more expensive.
CFD: what and why?
7. PAGE 7
• Modeling approach: RANS vs. LES
o Reynolds-averaged Navier-Stokes: time-averaged
solution.
• Mean flow is ‘solved’, all eddies are ‘modeled’.
o Large Eddy Simulation: time-dependent solution.
• Large eddies are ‘solved’, smaller eddies are ‘modeled’.
• More accurate, but computationally far more expensive.
CFD: what and why?
8. PAGE 8
2. Natural ventilation: Indoor airflow
Dr.ir. Twan van Hooff Leuven University / TU/e
Prof.dr.ir. Bert Blocken TU/e – Leuven University
Prof.dr.ir. GertJan van Heijst TU/e
Prof.dr.ir. Tine Baelmans Leuven University
Prof.dr.ir. Johan Meyers Leuven University
Prof.dr.ir. Jan Carmeliet ETH Zurich / EMPA
Dr.ir. Thijs Defraeye ETH Zurich / EMPA
9. PAGE 9
• Mixing ventilation
o Previous studies conducted mostly for fully turbulent flows
(high Reslot values) (e.g. Nielsen 1974, Chen 1995).
o Lack of studies on transitional flows (low Reslot).
Indoor airflow
Reslot = U0h/ν
10. PAGE 10
• Transitional flow
Indoor airflow
Flow
Flow
Re = UL/ν
U = characteristic velocity [m/s]
L = characteristic length scale [m]
ν = kinematic viscosity [m2/s]
Fully turbulent
Modified after Gogineni and Shih 1997.
11. PAGE 11
• Transitional ventilation flow
o General
• Supply jet region (low velocity/turbulence intensity)
• Near buoyant plumes
• Corners of enclosure
o Operating theatres
o Airplane cabins
Indoor airflow
Aircraft cabin ventilation
(http://www.travelfreak.com/2012/09/18/airplane‐health‐tips‐
the‐doctors/)
Operating theatre ventilation
(http://www.ikv.uk.com/Medical‐Air‐Technologies.html)
Office ventilation
(http://images.businessweek.com/ss/08/02/0213_dag
her_engineering/source/9.htm)
12. PAGE 12
• Reduced-scale experiments
Indoor airflow
van Hooff T, Blocken B, Defraeye T, Carmeliet J, van Heijst GJF, 2012. PIV measurements and analysis
of transitional flow in a reduced‐scale model: ventilation by a free plane jet with Coanda effect.
Building and Environment 56: 301‐313.
13. PAGE 13
• Reduced-scale experiments
Indoor airflow
van Hooff T, Blocken B, Defraeye T, Carmeliet J, van Heijst GJF, 2012. PIV measurements and analysis
of transitional flow in a reduced‐scale model: ventilation by a free plane jet with Coanda effect.
Building and Environment 56: 301‐313.
14. PAGE 14
• Reduced-scale experiments
o Flow visualizations
Indoor airflow
van Hooff T, Blocken B, Defraeye T, Carmeliet J, van Heijst GJF, 2012. PIV measurements of a plane wall
jet in a confined space at transitional slot Reynolds numbers. Experiments in Fluids 53(2): 499‐517.
15. PAGE 15
Outlet
Indoor airflow
van Hooff T, Blocken B, Defraeye T, Carmeliet J, van Heijst GJF, 2012. PIV measurements of a plane wall jet
in a confined space at transitional slot Reynolds numbers. Experiments in Fluids 53(2): 499‐517.
16. PAGE 16
• Reduced-scale experiments
o Flow visualizations in vertical center plane
Indoor airflow
van Hooff T, Blocken B, Defraeye T, Carmeliet J, van Heijst GJF, 2012. PIV measurements of a plane wall jet in a confined
space at transitional slot Reynolds numbers. Experiments in Fluids 53(2): 499‐517.
17. PAGE 17
• Reduced-scale experiments
o PIV measurements in vertical center plane
Indoor airflow
van Hooff T, Blocken B, Defraeye T, Carmeliet J, van Heijst GJF, 2012. PIV measurements of a
plane wall jet in a confined space at transitional slot Reynolds numbers. Experiments in Fluids
53(2): 499‐517.
18. PAGE 18
• Reduced-scale experiments
o PIV measurements in vertical center plane
• Setup
• 2D PIV system Nd:Yag (532 nm) double-cavity laser (2 x 200 mJ,
repetition rate < 10 Hz)
• CCD (Charge Coupled Device) camera (1376 x 1040 pixel, 10 fps)
positioned perpendicular to the water cube
• Seeding by hollow glass micro spheres (3M; type K1); ds = 30–115
μm
• Software package Davis 7.1 (LaVision)
• Time-averaged velocities and turbulence intensities calculated from
360 uncorrelated samples measured at 2 Hz
Indoor airflow
19. PAGE 19
• Reduced-scale experiments
o PIV measurements in vertical center plane
• Time-averaged velocity vector fields in vertical center plane
Indoor airflow
van Hooff T, Blocken B, Defraeye T, Carmeliet J, van Heijst GJF, 2012. PIV measurements of
a plane wall jet in a confined space at transitional slot Reynolds numbers. Experiments in
Fluids 53(2): 499‐517.
20. PAGE 20
• Reduced-scale experiments
o PIV measurements in vertical center plane
• Time-averaged velocity vector fields in vertical center plane
Indoor airflow
van Hooff T, Blocken B, Defraeye T, Carmeliet J, van Heijst GJF, 2012. PIV measurements of
a plane wall jet in a confined space at transitional slot Reynolds numbers. Experiments in
Fluids 53(2): 499‐517.
21. PAGE 21
• CFD simulations
o Steady 3D Reynolds-Averaged Navier-Stokes equations
• Four different turbulence models
• RNG k-ε model (Yakhot et al. 1992)
• Low-Re k-ε model (Chang et al. 1995)
• SST k-ω model (Menter 1994)
• Low-Re stress-omega Reynolds Stress Model (Wilcox 1998)
o Low-Reynolds number modeling
• Solving the flow all the way down to the wall, including the
thin laminar sublayer
• y* preferably around 1
Indoor airflow
22. PAGE 22
• CFD simulations
o Model and grid
Indoor airflow
van Hooff T, Blocken B, van Heijst GJF, 2013. On the suitability of steady RANS CFD for forced
mixing ventilation at transitional slot Reynolds numbers. Indoor Air 23(3): 236‐249.
1.25 million cells
23. PAGE 23
• CFD simulations
o Boundary conditions
• Velocity based on Reynolds number
• Turbulence intensity based on PIV measurements
• Zero static pressure at outlet
• Walls modeled as no-slip walls
Indoor airflow
van Hooff T, Blocken B, van Heijst GJF, 2013. On the suitability of steady RANS CFD for forced
mixing ventilation at transitional slot Reynolds numbers. Indoor Air 23(3): 236‐249.
24. PAGE 24
• CFD simulations
o Results: Re ≈ 1,000
Indoor airflow
van Hooff T, Blocken B, van Heijst GJF, 2013. On the suitability of steady RANS CFD for forced
mixing ventilation at transitional slot Reynolds numbers. Indoor Air 23(3): 236‐249.
25. PAGE 25
• CFD simulations
o Results: Re ≈ 1,000
Indoor airflow
van Hooff T, Blocken B, van Heijst GJF, 2013. On the suitability of steady RANS CFD for forced
mixing ventilation at transitional slot Reynolds numbers. Indoor Air 23(3): 236‐249.
26. PAGE 26
• CFD simulations
o Results: Re ≈ 1,000
Indoor airflow
van Hooff T, Blocken B, van Heijst GJF, 2013. On the suitability of steady RANS CFD for forced
mixing ventilation at transitional slot Reynolds numbers. Indoor Air 23(3): 236‐249.
27. PAGE 27
• CFD simulations – non-isothermal (preliminary)
o Results: Re ≈ 2,800
Indoor airflow
o L = 2 m
o Inlet height = h/L = 0.025
o Floor heating
o Other walls adiabatic
o Supply temperature -7°C
28. PAGE 28
• CFD simulations – non-isothermal (preliminary)
o Results: Re ≈ 2,800
Indoor airflow
o L = 2 m
o Inlet height = h/L = 0.025
o Floor heating
o Other walls adiabatic
o Supply temperature -7°C
29. PAGE 29
3. Natural ventilation: Ventilative cooling
Ir. Katarina Kosutova TU/e
Prof.dr.ir. Bert Blocken TU/e – Leuven University
Prof.dr.ir. Jan Hensen TU/e
Dr.ir. Twan van Hooff Leuven University
Kosutova K, van Hooff T, Blocken B, Hensen JLM, 2015. CFD analysis of ventilative cooling in a generic
isolated building equipped with ventilation louvers. Healthy Buildings Europe 2015, 18-20 May 2015,
Eindhoven, The Netherlands.
30. PAGE 30
• PhD research: Katarina Kosutova
o Multi-scale computational assessment of ventilative cooling as an
energy-efficient measure to avoid indoor overheating
Ventilative cooling
31. PAGE 31
Ventilative cooling refers to the use of natural or mechanical ventilation strategies
to cool indoor spaces [1].
.
Why ventilative cooling?
Sustainable and energy efficient solution to reduce the cooling demand of the
building.
Helps to prevent indoor overheating.
Helps to maintain healthy indoor environment.
Objective of this sub-research
To investigate the influence of ventilation louver slat angle on the air exchange
efficiency and heat removal effectiveness in a generic isolated building.
[1] www.venticool.eu, 01.05.2015
Ventilative cooling
32. PAGE 32
www.glasbau-hahn.com
Energy efficient
Possible to control ventilation due to operable slats
Can be opened during rain to allow fresh washed air
to enter the house
Seal tightly when closed
Mostly used in warm climates
Ventilative cooling
• Ventilation louvers
34. PAGE 34
[2] Karava P, Stathopoulos T, Athienitis AK. 2011. Airflow assessment in cross-ventilated
buildings with operable façade elements. Build. Environ. 46(1): 266-279.
[m]
Ventilative cooling
• Building model
• Generic isolated building was chosen in order to validate the CFD
simulations with the wind tunnel PIV measurements[2].
35. PAGE 35
Building geometry (without louvers)
Generic isolated building
H = 4 m (height of the building)
Generic isolated building
H = 4 m (height of the building)
Computational domain
Ventilative cooling
• Building model
36. PAGE 36
Building geometry (without louvers)
Generic isolated building
Configurations considered:
Window without any louvers
Windows equipped with ventilation louvers
with slat angles: 0°, 30° and 45°
Generic isolated building
Configurations considered:
Window without any louvers
Windows equipped with ventilation louvers
with slat angles: 0°, 30° and 45°
Building geometry (with louvers)
Ventilative cooling
• Building geometry and mesh
37. PAGE 37
Building geometry (without louvers)
Generic isolated building
Configurations considered:
Window without any louvers
Windows equipped with ventilation louvers
with slat angles: 0°, 30° and 45°
Generic isolated building
Configurations considered:
Window without any louvers
Windows equipped with ventilation louvers
with slat angles: 0°, 30° and 45°
Building geometry (with louvers)
Grid created in Gambit
Size of the grid based on the grid-sensitivity
analysis
Basic grid: 6,766,578 cells
Hexahedral cells
Grid created in Gambit
Size of the grid based on the grid-sensitivity
analysis
Basic grid: 6,766,578 cells
Hexahedral cells
Ventilative cooling
• Building geometry and mesh
38. PAGE 38
Logarithmic velocity profile imposed at the inlet
Inlet turbulent kinetic energy (k)
Inlet specific dissipation rate (ω)
Logarithmic velocity profile imposed at the inlet
Inlet turbulent kinetic energy (k)
Inlet specific dissipation rate (ω)
k a UIU
2
* 3
ABL
0
u
(y y )
U y
uABL
*
ln
y y0
y0
Ck
,
κ = 0.42
u* = 0.363 m/s
y0 = 0.00125 m
Cμ = 0.09
a = 1[3]
assuming σu = (σv + σw)
[3] Ramponi R, Blocken B. 2012. CFD simulation of cross-ventilation for a generic isolated
building: Impact of computational parameters. Build Environ 53: 34-48.
Ventilative cooling
• CFD: boundary conditions
39. PAGE 39
Inlet: velocity inlet, θi = 20°C
Outlet: pressure outlet
Side and top planes: symmetry
Ground : wall, ks = 0.0125 m
Cs = 0.979
Building surfaces: wall, θw = 30°C
Inlet: velocity inlet, θi = 20°C
Outlet: pressure outlet
Side and top planes: symmetry
Ground : wall, ks = 0.0125 m
Cs = 0.979
Building surfaces: wall, θw = 30°C
s
s
C
y
k 0
793
.
9
[4]
[4] Blocken B, Stathopoulos T, Carmeliet J. 2007. CFD simulation of the atmospheric
boundary layer: wall function problems. Atmos Environ 41(2): 238-252.
Ventilative cooling
• CFD: boundary conditions
40. PAGE 40
3D steady RANS equations
SST k-ω turbulence model [5]
SIMPLE for pressure-velocity coupling
PRESTO! for pressure interpolation
Second-order discretization schemes for momentum, k, ω and energy
3D steady RANS equations
SST k-ω turbulence model [5]
SIMPLE for pressure-velocity coupling
PRESTO! for pressure interpolation
Second-order discretization schemes for momentum, k, ω and energy
[5] Menter FR. 1994. Two-equation eddy viscosity turbulence models for engineering
applications, AIAA J, 32: 1598-1605.
Ventilative cooling
• CFD: parameters and settings
41. PAGE 41
Contours of dimensionless velocity (|V|/Uref) in the vertical
center plane, Uref = 6.97 m/s
Ventilative cooling
Geometry of the louvers
• CFD: Results
42. PAGE 42
Contours of dimensionless temperature (θ/θref) in the vertical
center plane, θref = 20°C
Ventilative cooling
• CFD: Results
Geometry of the louvers
43. PAGE 43
Air exchange efficiency
Geometry of the louvers
100
out
(2av)
Ventilative cooling
45. PAGE 45
CFD simulations were performed for a relatively high reference wind speed
(Uref = 6.97 m/s).
Future research
CFD simulations for lower wind speed
CFD simulations for different values of y0
More realistic building geometry
Influence of the urban surrounding on the air
exchange efficiency and heat removal effectiveness
CFD simulations for lower wind speed
CFD simulations for different values of y0
More realistic building geometry
Influence of the urban surrounding on the air
exchange efficiency and heat removal effectiveness
Ventilative cooling
• Discussion
46. PAGE 46
Contours of dimensionless velocity (|V|/Uref) in the vertical
center plane, Uref = 1.15 m/s
Ventilative cooling
• CFD: Results
Geometry of the louvers
47. PAGE 47
Contours of dimensionless temperature (θ/θref) in the vertical
center plane, θref = 20°C
Ventilative cooling
Geometry of the louvers
• CFD: Results
48. PAGE 48
4. Natural ventilation: Stadium study
Dr.ir. Twan van Hooff Leuven University – TU/e
Prof.dr.ir. Bert Blocken TU/e – Leuven University
49. PAGE 49
• Stadium description
o Amsterdam ‘ArenA’
• Completed in 1995 in Amsterdam
• Multifunctional stadium
• Capacity of 51,628 spectators
• Retractable (semi-)transparent roof
• No HVAC Services
• Natural ventilation through the roof and
openings in the building facade
Stadium study
51. PAGE 51
• Stadium description
o Natural ventilation through the roof, corners of stadium and
relatively small openings in the building facade
Ventilation opening Surface area (m2)
Roof 4,400
Four openings in corners of stadium 166
Opening between stand and roof construction 130
Opening between fixed roof and movable roof 85
Stadium study
52. PAGE 52
• Full-scale measurements (1)
o During summer:
• Temperature
• Relative humidity
• Air speed
• Globe temperature
• CO2 concentration
(All measured on 4 positions inside the stadium. T en RH also measured outside the stadium)
• Irradiance of the sky
Stadium study
53. PAGE 53
• Full-scale measurements (1)
o Measurement positions
Measuring positions for the air temperature, relative humidity, CO2 concentration and air speed () inside the stadium
with (a) positions in a horizontal plane; (b) positions in a vertical plane.
Stadium study
54. PAGE 54
• Full-scale measurements (1)
van Hooff T, Blocken B, 2012. Full‐scale measurements of indoor environmental conditions and natural
ventilation in a large semi‐enclosed stadium: possibilities and limitations for CFD validation. Journal of
Wind Engineering and Industrial Aerodynamics 104‐106: 330‐341.
Stadium study
55. PAGE 55
• Full-scale measurements (2)
o Wind speed measurements inside and around the stadium
Measurement with ultrasonic anemometer outside the ArenA
Stadium study
Measurement with ultrasonic anemometer in the corners of the ArenA
56. PAGE 56
• CFD simulations
o 3D steady state CFD simulations
• Domain: 2,900 x 2,900 x 908.5 m3 (LxWxH)
• Hybrid grid (5.5 million cells)
• Realizable k-ε turbulence model (Shih et al. 1995)
• Standard wall functions (Launder and Spalding 1974) with sand-grain
based roughness modification (Cebeci and Bradshaw 1977).
• Logarithmic wind speed profile (U10 = 5 m/s, y0 = 0.5 m or 1.0 m)
• Several wind directions
• Estimated surface temperatures imposed to take into account solar
irradiation
Stadium study
58. PAGE 58
• CFD simulations
o Grid
Stadium study
5.5 million cells
59. PAGE 59
• CFD simulations
o Grid-sensitivity analysis
Stadium study
60. PAGE 60
• CFD simulations
o Validation using wind speed measurements
Stadium study
61. PAGE 61
Stadium study
Van Hooff T, Blocken B, 2010. On the effect of wind direction and urban surroundings on natural
ventilation of a large semi‐enclosed stadium. Computers & Fluids 39, 1146‐1155.
• CFD simulations
o Results
62. PAGE 62
• CFD simulations
o Results
Van Hooff T, Blocken B, 2010. On the effect of wind direction and urban surroundings on natural
ventilation of a large semi‐enclosed stadium. Computers & Fluids 39, 1146‐1155.
Stadium study
63. PAGE 63
• CFD simulations
o Results
Stadium study
Van Hooff T, Blocken B, 2010. On the effect of wind direction and urban surroundings on natural
ventilation of a large semi‐enclosed stadium. Computers & Fluids 39, 1146‐1155.
64. PAGE 64
Contours of wind speed ratio
U/U10 in four horizontal planes,
for φ = 196° (SSW) and U10 = 5
m/s; at (a) 10 m; (b) 20 m; (c)
40 m and (d) 60 m above the
ArenA deck.
Stadium study
66. PAGE 66
• CFD simulations can provide high-resolution data on
natural ventilation flows.
• Both basic and applied research is needed.
o Understanding the flow
o Optimizing ventilation flows for practical situations
• Experimental studies are imperative.
o To obtain valuable insights in physical processes
o For validation purposes
Closing remarks
67. CFD-simulaties van natuurlijke
ventilatie
Bedankt voor uw aandacht!
Dr.ir. Twan van Hooff
FWO postdoctoral research fellow
KU Leuven
twan.vanhooff@bwk.kuleuven.be
Prof.dr.ir. Bert Blocken
TU Eindhoven / KU Leuven