This document summarizes research comparing the effects of complex urban geometries versus simplified representations in mesoscale modeling. It tests the hypothesis that cities can be accurately modeled as regular arrays of cubes or canopies. The document describes simulations of drag forces, shortwave radiation exchange, and wind flow for a real urban geometry compared to simplified representations of long canopies and cubes while keeping total built volume equal. Results show differences in drag, radiation absorption on walls and ground, and velocity fields between the real and simplified geometries.
Comparative Study of Static and Dynamic Seismic Analysis of Multistoried RCC ...IJERA Editor
Reinforced Concrete (RC) building frames are most common types of constructions in urban India. These are subjected to several types of forces during their lifetime, such as static forces due to dead and live loads and dynamic forces due to earthquake. In the present work, two tall buildings (a G+10 and a G+25 structure), presumed to be situated in seismic zone III, are analyzed by using two different methods viz. equivalent static analysis method and response spectrum method, using ETAB 15 software. From analysis results, the parameters like storey drift, storey displacement, Axial Load, Bending Moments are determined for comparative study. Results established the superiority of the Response spectrum method over the Equivalent static analysis method.
Comparative Study of Static and Dynamic Seismic Analysis of Multistoried RCC ...IJERA Editor
Reinforced Concrete (RC) building frames are most common types of constructions in urban India. These are subjected to several types of forces during their lifetime, such as static forces due to dead and live loads and dynamic forces due to earthquake. In the present work, two tall buildings (a G+10 and a G+25 structure), presumed to be situated in seismic zone III, are analyzed by using two different methods viz. equivalent static analysis method and response spectrum method, using ETAB 15 software. From analysis results, the parameters like storey drift, storey displacement, Axial Load, Bending Moments are determined for comparative study. Results established the superiority of the Response spectrum method over the Equivalent static analysis method.
Study of Earthquake Forces By Changing the Location of Lift CoreIJERA Editor
Lift core is an important element for strengthening of structure in earthquake prone area (Mw=6.5 or more).
This paper deals with use of lift cores to resist the seismic forces and its effect by changing the lift core location.
The study for G+5 and G+10 type frame buildings are taken under consideration. These buildings are further
subdivided as per soil strata i.e. hard, medium, and soft. Two locations of lift core considered for studies i.e.
centre core and corner core. Zone V is considered for all buildings which will cause maximum base shear to the
structure. Study is focused on comparative static and dynamic analysis which will show graphical
representation of G+5 and G+10 building along with soil type. Economy is studied in analysis.
Comparative Study of Static and Dynamic Seismic Analysis of Multistoried RCC ...IJERA Editor
Reinforced Concrete (RC) building frames are most common types of constructions in urban India. These are subjected to several types of forces during their lifetime, such as static forces due to dead and live loads and dynamic forces due to earthquake. In the present work, two tall buildings (a G+10 and a G+25 structure), presumed to be situated in seismic zone III, are analyzed by using two different methods viz. equivalent static analysis method and response spectrum method, using ETAB 15 software. From analysis results, the parameters like storey drift, storey displacement, Axial Load, Bending Moments are determined for comparative study. Results established the superiority of the Response spectrum method over the Equivalent static analysis method.
Comparative Study of Static and Dynamic Seismic Analysis of Multistoried RCC ...IJERA Editor
Reinforced Concrete (RC) building frames are most common types of constructions in urban India. These are subjected to several types of forces during their lifetime, such as static forces due to dead and live loads and dynamic forces due to earthquake. In the present work, two tall buildings (a G+10 and a G+25 structure), presumed to be situated in seismic zone III, are analyzed by using two different methods viz. equivalent static analysis method and response spectrum method, using ETAB 15 software. From analysis results, the parameters like storey drift, storey displacement, Axial Load, Bending Moments are determined for comparative study. Results established the superiority of the Response spectrum method over the Equivalent static analysis method.
Study of Earthquake Forces By Changing the Location of Lift CoreIJERA Editor
Lift core is an important element for strengthening of structure in earthquake prone area (Mw=6.5 or more).
This paper deals with use of lift cores to resist the seismic forces and its effect by changing the lift core location.
The study for G+5 and G+10 type frame buildings are taken under consideration. These buildings are further
subdivided as per soil strata i.e. hard, medium, and soft. Two locations of lift core considered for studies i.e.
centre core and corner core. Zone V is considered for all buildings which will cause maximum base shear to the
structure. Study is focused on comparative static and dynamic analysis which will show graphical
representation of G+5 and G+10 building along with soil type. Economy is studied in analysis.
An Experimental Study on Vehicular Emission Dispersion through Single Storied...inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
Comparative Study of Various Seismic Analysis Methods for Rc StructureIJERA Editor
A large number of RC frame buildings have been built in India in recent years. Huge number of similarly designed and constructed buildings exist in the various towns and cities situated in moderate to severe seismic zones of the country. Analysis and design of such buildings for static forces is a routine affair these days because of availability of affordable computers and specialized programs which can be used for the analysis. On the other hand, dynamic analysis is a time consuming process and requires additional input related to mass of the structure, and an understanding of structural dynamics for interpretation of analytical results. Reinforced Concrete (RC) frame buildings are most common type of constructions in urban India, which are subjected to several types of forces during their lifetime, such as static forces due to dead and live loads and dynamic forces due to earthquake. To ensure safety against seismic forces of multi-storied building hence, there is need to study of seismic analysis to design earthquake resistance structures. In the present study a multi-storied framed structure is selected, And Linear seismic analysis is done for the building by static method (Equivalent Static Method) and dynamic method (Response Spectrum Method & Time history Method) using ETAB2016 as per the IS-1893-2002-Part-1. As a result, the response of structure has been obtained for considered building models, based on each methods of analysis, and then the results are compared with each other.
Effect of Wind Direction through Single Storied Building Model Configurations...inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
The Journal will bring together leading researchers, engineers and scientists in the domain of interest from around the world. Topics of interest for submission include, but are not limited to:
This paper is a mathematical study for finding the amount of solar radiation on the surface of the
Photovoltaic (PV) system affected due to the variation in the slope (tilt angle) of the PV system along with the
background theory of the attenuation of the solar radiation. The power density is maximum when the solar moduleabsorbing
surface is perpendicular to the sun and in all other cases module power is always lesser than the incident
power. Hence extra addition of panels with fixed tilt is no longer economical viable when electricity demand
increases. Theoretical estimation of solar radiation on the slope of the PV surface from the radiation available on
the horizontal surface is evaluated and the results are presented on the basis of the data available and proposed
mathematical model for the calculation of the total amount of solar radiation on tilted surface.
10 simple mathematical approach for granular fill Ahmed Ebid
improving soil parameters using dynamic
compaction of was intensively studied by many researchers since
1980’s. Earlier researchers depended on statistical analysis of
many case studies and soil dynamic principals to develop
empirical formula used in designing dynamic compaction
procedure. Recent researchers used different finite element
models to describe the behavior of soil under dynamic
compaction; those models varied between 1-D simple model and
up to 3-D sophisticated ones. The aim of this research is to
introduce a simple mathematical approach to simulate ground
deformations and soil parameters improvement due to dynamic
compaction. The proposed approach consists of two equations, the
1st one used to calculate the ground settlement due to one temper
drop, the 2nd one used to calculate the updated soil parameters
due to the ground settlement from the previous drop. By applying
the two equations successively, both ground settlement and soil
parameters improvement could be calculated after each tamper
drop. The proposed approach was applied on four case studies and
its results were so close to measured ones. The proposed approach
could be used in designing or testing the dynamic compaction
procedures and also in monitoring the quality of execution by
comparing the measured settlement after each drop with
calculated one.
Effect of Wind Direction through Double Storied Building Model Configurations...inventionjournals
: Effect of wind direction on plume dispersion around urban buildings has been investigated by physical modelling using arrays of buildings- like obstacles at scale 1:100 in boundary layer wind tunnel for double storied buildings and compared with field data. The particular effect of obstacle width- to - height ratio (S/H) was examined for a fixed obstacle plan area density. Series of experiments have been carried out in which the wind direction varied in steps of 5 for selected orientation of line source at 900 , 95, 100 and 105. Further, from the observation, it was concluded that the maximum lateral concentration shift to upward the wind direction of line source is increased for inline double storied buildings model configuration. It can be concluded, the wind tunnel results showed that concentrations at downwind distances decreased as the wind direction increases (positive values) for measured orientation of line source in inline double storied buildings model configuration. In comparison, experimentally observed σz values are below the field values. They were best fitted with power-law profiles. The non-dimensional concentration for both the field and wind tunnel results of double storied inline buildings configuration seems to be more or less uniform. Values of vertical spread parameters for double storied inline array configuration and field data were followed a similar trend but inline array configuration of double storied buildings model, non-dimensional concentrations were typically twice larger compared to the field data. This is attributed to the fact that the tracer material is quite concentrated in the recirculation region in inline array configuration of the double storied buildings model.
Robust 3D Geological Models: Hard Data is KeyFF Explore 3D
Understanding and incorporating 2D data, whether from surface field work or underground mine mapping, should always be the starting point of an integrated and coherent 3D geologic model, especially for areas with great geometric contrasts. Without this valuable data, 3D modelling is essentially performed with blinders on, and its absence results in a model that is too theory-driven, and lacks input from geologists and “real” field data.
Three-dimensional geologic models require complete, homogeneous and valid databases. The resulting 3D models are directly based on and rely on high-quality data. The data comprises both surface and underground observations. “Raw” or “hard” data should always be assigned more weight and act as rigid control points in 3D models. Hard data should always be distinguishable from interpreted data in 3D models. Investing the necessary time to learn how to homogenize and structure raw data in a rigorous way will be paid back during the 3D interpretation process.
Once 3D models are completed, they should be used as an exploration tool, populating their cells with user-chosen properties. Both quantitative and qualitative properties can be interpolated throughout the cells of the 3D model for further querying and questioning. Thus, the extra benefit of 3D map models is their use as dynamic interactive tools to help define new mineral exploration targets at depth.
A 3D map model is not a goal but a tool that should be dynamic, modified, questioned, shared and updated. Its future usefulness is determined by how well it can be utilized by a multi-disciplinary team of geologists, geophysicists, geochemists, engineers, metallurgists and environmental experts.
SEISMIC RESPONSE MODEL INCLUDING SSI OF RC BUILDINGS ON ISOLATED AND RAFT FOU...IAEME Publication
From the literature it is clear that the interaction between the superstructure and the soil foundation has not been taken into consideration in most of the research work. The effect of
construction phase and mode of superstructure loading on the response of structure and foundation has not been given attention. The purpose of this study is to formulate and investigate analytical model for natural period of reinforced frame buildings (low, medium and high rise) based on
RPA2013 with fixed and flexible base. Three types of soil hard, medium and soft are used; isolated foundation for hard and medium soil – sites S1, S2 and raft foundations for soft soil sites S3 and S4.
Development of Methodology for Determining Earth Work Volume Using Combined S...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
Monte Carlo simulation for seismic analysis of a long span suspension bridgeFranco Bontempi
Sgambi L et al. Monte Carlo simulation for seismic analysis of a long span suspension bridge. Eng Struct (2014), http://
dx.doi.org/10.1016/j.engstruct.2014.08.051
The seismic analysis of long-span cable suspended bridges is undoubtedly a problem in structural analysis that involves a high number of uncertain parameters. In this work, through a probabilistic approach (Monte Carlo simulation) seismic analysis is carried out able to take into account the variability of certain factors relating to the seismic input. Displacement time histories, necessary to define seismic scenarios, are built artificially based on the response spectrum of the site. The analysis is carried out using a 3D numerical model built using one-dimensional finite elements using ADINA software code. This model has been developed in conjunction with a purpose-built program in FORTRAN language to conduct the Monte Carlo simulations. The results expressed in terms of displacements and stresses are described by their average value and their variance.
Structural morphology optimization by evolutionary proceduresStroNGER2012
The paper deals with the identification of optimal structural morphologies through evolutionary procedures.
Two main approaches are considered. The first one simulates the Biological Growth (BG) of natural structures like the bones and the trees. The second one, called Evolutionary Structural Optimization (ESO), removes material at low stress level. Optimal configurations are addressed by proper optimality indexes and by a monitoring of the structural response. Design graphs suitable to this purpose are introduced and employed in the optimization of a pylon carrying a suspended roof and of a bridge under multiple loads.
An Experimental Study on Vehicular Emission Dispersion through Single Storied...inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
Comparative Study of Various Seismic Analysis Methods for Rc StructureIJERA Editor
A large number of RC frame buildings have been built in India in recent years. Huge number of similarly designed and constructed buildings exist in the various towns and cities situated in moderate to severe seismic zones of the country. Analysis and design of such buildings for static forces is a routine affair these days because of availability of affordable computers and specialized programs which can be used for the analysis. On the other hand, dynamic analysis is a time consuming process and requires additional input related to mass of the structure, and an understanding of structural dynamics for interpretation of analytical results. Reinforced Concrete (RC) frame buildings are most common type of constructions in urban India, which are subjected to several types of forces during their lifetime, such as static forces due to dead and live loads and dynamic forces due to earthquake. To ensure safety against seismic forces of multi-storied building hence, there is need to study of seismic analysis to design earthquake resistance structures. In the present study a multi-storied framed structure is selected, And Linear seismic analysis is done for the building by static method (Equivalent Static Method) and dynamic method (Response Spectrum Method & Time history Method) using ETAB2016 as per the IS-1893-2002-Part-1. As a result, the response of structure has been obtained for considered building models, based on each methods of analysis, and then the results are compared with each other.
Effect of Wind Direction through Single Storied Building Model Configurations...inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
The Journal will bring together leading researchers, engineers and scientists in the domain of interest from around the world. Topics of interest for submission include, but are not limited to:
This paper is a mathematical study for finding the amount of solar radiation on the surface of the
Photovoltaic (PV) system affected due to the variation in the slope (tilt angle) of the PV system along with the
background theory of the attenuation of the solar radiation. The power density is maximum when the solar moduleabsorbing
surface is perpendicular to the sun and in all other cases module power is always lesser than the incident
power. Hence extra addition of panels with fixed tilt is no longer economical viable when electricity demand
increases. Theoretical estimation of solar radiation on the slope of the PV surface from the radiation available on
the horizontal surface is evaluated and the results are presented on the basis of the data available and proposed
mathematical model for the calculation of the total amount of solar radiation on tilted surface.
10 simple mathematical approach for granular fill Ahmed Ebid
improving soil parameters using dynamic
compaction of was intensively studied by many researchers since
1980’s. Earlier researchers depended on statistical analysis of
many case studies and soil dynamic principals to develop
empirical formula used in designing dynamic compaction
procedure. Recent researchers used different finite element
models to describe the behavior of soil under dynamic
compaction; those models varied between 1-D simple model and
up to 3-D sophisticated ones. The aim of this research is to
introduce a simple mathematical approach to simulate ground
deformations and soil parameters improvement due to dynamic
compaction. The proposed approach consists of two equations, the
1st one used to calculate the ground settlement due to one temper
drop, the 2nd one used to calculate the updated soil parameters
due to the ground settlement from the previous drop. By applying
the two equations successively, both ground settlement and soil
parameters improvement could be calculated after each tamper
drop. The proposed approach was applied on four case studies and
its results were so close to measured ones. The proposed approach
could be used in designing or testing the dynamic compaction
procedures and also in monitoring the quality of execution by
comparing the measured settlement after each drop with
calculated one.
Effect of Wind Direction through Double Storied Building Model Configurations...inventionjournals
: Effect of wind direction on plume dispersion around urban buildings has been investigated by physical modelling using arrays of buildings- like obstacles at scale 1:100 in boundary layer wind tunnel for double storied buildings and compared with field data. The particular effect of obstacle width- to - height ratio (S/H) was examined for a fixed obstacle plan area density. Series of experiments have been carried out in which the wind direction varied in steps of 5 for selected orientation of line source at 900 , 95, 100 and 105. Further, from the observation, it was concluded that the maximum lateral concentration shift to upward the wind direction of line source is increased for inline double storied buildings model configuration. It can be concluded, the wind tunnel results showed that concentrations at downwind distances decreased as the wind direction increases (positive values) for measured orientation of line source in inline double storied buildings model configuration. In comparison, experimentally observed σz values are below the field values. They were best fitted with power-law profiles. The non-dimensional concentration for both the field and wind tunnel results of double storied inline buildings configuration seems to be more or less uniform. Values of vertical spread parameters for double storied inline array configuration and field data were followed a similar trend but inline array configuration of double storied buildings model, non-dimensional concentrations were typically twice larger compared to the field data. This is attributed to the fact that the tracer material is quite concentrated in the recirculation region in inline array configuration of the double storied buildings model.
Robust 3D Geological Models: Hard Data is KeyFF Explore 3D
Understanding and incorporating 2D data, whether from surface field work or underground mine mapping, should always be the starting point of an integrated and coherent 3D geologic model, especially for areas with great geometric contrasts. Without this valuable data, 3D modelling is essentially performed with blinders on, and its absence results in a model that is too theory-driven, and lacks input from geologists and “real” field data.
Three-dimensional geologic models require complete, homogeneous and valid databases. The resulting 3D models are directly based on and rely on high-quality data. The data comprises both surface and underground observations. “Raw” or “hard” data should always be assigned more weight and act as rigid control points in 3D models. Hard data should always be distinguishable from interpreted data in 3D models. Investing the necessary time to learn how to homogenize and structure raw data in a rigorous way will be paid back during the 3D interpretation process.
Once 3D models are completed, they should be used as an exploration tool, populating their cells with user-chosen properties. Both quantitative and qualitative properties can be interpolated throughout the cells of the 3D model for further querying and questioning. Thus, the extra benefit of 3D map models is their use as dynamic interactive tools to help define new mineral exploration targets at depth.
A 3D map model is not a goal but a tool that should be dynamic, modified, questioned, shared and updated. Its future usefulness is determined by how well it can be utilized by a multi-disciplinary team of geologists, geophysicists, geochemists, engineers, metallurgists and environmental experts.
SEISMIC RESPONSE MODEL INCLUDING SSI OF RC BUILDINGS ON ISOLATED AND RAFT FOU...IAEME Publication
From the literature it is clear that the interaction between the superstructure and the soil foundation has not been taken into consideration in most of the research work. The effect of
construction phase and mode of superstructure loading on the response of structure and foundation has not been given attention. The purpose of this study is to formulate and investigate analytical model for natural period of reinforced frame buildings (low, medium and high rise) based on
RPA2013 with fixed and flexible base. Three types of soil hard, medium and soft are used; isolated foundation for hard and medium soil – sites S1, S2 and raft foundations for soft soil sites S3 and S4.
Development of Methodology for Determining Earth Work Volume Using Combined S...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
Monte Carlo simulation for seismic analysis of a long span suspension bridgeFranco Bontempi
Sgambi L et al. Monte Carlo simulation for seismic analysis of a long span suspension bridge. Eng Struct (2014), http://
dx.doi.org/10.1016/j.engstruct.2014.08.051
The seismic analysis of long-span cable suspended bridges is undoubtedly a problem in structural analysis that involves a high number of uncertain parameters. In this work, through a probabilistic approach (Monte Carlo simulation) seismic analysis is carried out able to take into account the variability of certain factors relating to the seismic input. Displacement time histories, necessary to define seismic scenarios, are built artificially based on the response spectrum of the site. The analysis is carried out using a 3D numerical model built using one-dimensional finite elements using ADINA software code. This model has been developed in conjunction with a purpose-built program in FORTRAN language to conduct the Monte Carlo simulations. The results expressed in terms of displacements and stresses are described by their average value and their variance.
Structural morphology optimization by evolutionary proceduresStroNGER2012
The paper deals with the identification of optimal structural morphologies through evolutionary procedures.
Two main approaches are considered. The first one simulates the Biological Growth (BG) of natural structures like the bones and the trees. The second one, called Evolutionary Structural Optimization (ESO), removes material at low stress level. Optimal configurations are addressed by proper optimality indexes and by a monitoring of the structural response. Design graphs suitable to this purpose are introduced and employed in the optimization of a pylon carrying a suspended roof and of a bridge under multiple loads.
Calculation of Fluid Dynamic for Wind Flow around Reinforced Concrete WallsIJERA Editor
A study on the flow phenomena around free-standing walls is important in practical building construction. In the present paper a numerical study is conducted for two- dimensional incompressible steady flow around freestanding walls using low-Re k-co turbulence model. The separation regions downstream the wall and on the roof of the leeward were predicted. Finally, results of numerical simulation are presented in the form of velocity vectors, velocity contour, pressure contours and streamlines
45 investigation paper id 0008 edit septianIAESIJEECS
Most numerical studies on flow over buildings simplify the geometry of the roof and assume that it is flat. This may lead to misrepresentation of the flow as the roof of actual buildings contains some sort of roughness. In this study, the flow over the administrative building of Universiti Tenaga Nasional is investigated for multidirectional flow conditions. The actual topology of the building is gridded and simulated using the steady-state Reynolds-averaged Navier-Stokes equation. Four points at the top of the building are identified and the wind statistics at these designated locations at three different heights are investigated. The optimal location with the highest average wind speed and consistent wind speeds for all wind angles is identified and is earmarked as a potential location to install the wind turbine.
The Illustration of Mechanism and development of Atmospheric dynamic peripher...iosrjce
This research papers illustrates and justify the soil shifting and a pre determinant mechanism of
testing and real time analysis of soil composition and the behavior by concentric waveform generation and the
field effect of the concentric waves thus formed. The waveforms generated are being analyzed using a field wire
enclosure structure having a non conducting cylinder with circular magnetic field effect induction. The
electrical pulses being generated are plotted against fluid viscosity behavior. The research paper illustrates
with conclusion and analysis that a correlation simulation model is possible with fluid properties to generate
non obvious prediction mechanism to possible pulse generator.
This project aims at simulating lid driven cavity flow problem using package MATLAB. Steady Incompressible Navier-Stokes equation with continuity equation will be studied at various Reynolds number. The main aim is to obtain the velocity field in steady state using the finite difference formulation on momentum equations and continuity equation. Reynold number is the pertinent parameter of the present study. Taylor’s series expansion has been used to convert the governing equations in the algebraic form using finite difference schemes.
Extradosed Bridges – Assessment of seismic damage using Ground Acceleration a...irjes
Forced vibration of structure for given Earthquake time history is governed by peak acceleration. For
cable stayed structures such as Extradosed cable stayed bridge it is difficult to predict dynamic response using
usual methods of dynamic analysis as applied to some other bridge structures like response spectrum analysis,
accurate analysis like time history analysis is time consuming and has time and cost effects. Nonlinearities can
only be considered in time history analysis. The proposed method correlates the peak ground acceleration
(PGA) and earthquake deformation ratio (EDR) which can be used for simplified dynamic analysis and can
prove handy tool for structural engineers to know earthquake related serviceability without much complicated
analysis at initial stages. This ratio can be used to present seismic damage indices. The method is proposed
considers Extradosed bridge for example.
Study of Soil Structure Interaction Effects on Multi-risers by applying soil ...Roshni Ramakrishnan
The response of a structure is affected by interaction between three linked systems, the
structure, the foundation and the soil underlying and surrounding the foundation. Soil-
Structure interaction analysis evaluates the collective response of these systems tospecified motion.The purpose of the thesis is to develop guidance for implementing soil-structure interaction inthe analysis and design of multi-risers such that the structural models include elements thataccount for the geotechnical and foundation conditions associated with buildings under consideration.
As part of the work, soil structure interaction procedures were applied to detailed example
applications to evaluate the influence of SSI components on the analysis results of dynamic
load cases ( as per IS 1893) and subsequently on the effect of the design of the structural members.
REVIEW OF THE URBAN HEAT ISLAND PHENOMENON ANALYSIS AS AN ADAPTATION TO CLIMA...civej
The modelling of the urban microclimate, in particular the phenomenon of the Urban Heat Island (UHI), is
becoming increasingly essential for city planning and urban design. The phenomenon analysis is
henceforth possible thanks to the increase in computational power, the link between simulation tools and
urban databases, which allow to represent explicitly the characteristics of the urban microclimate and to
better understand its effects, through the analysis and evaluation of the different impacts of the urban
climatic or anthropogenic contributors. However, the choice of the scale of the study depends on the
accuracy of the modelling approaches, the capacities of calculation and the availability and reliability of
the data. The contribution aims to highlight the phenomenon of the UHI based on a bibliographic study of
the latest research on this topic in Maghreb cities and the different strategies for adapting them to climate
change and for improving their resilience.
Safalta Digital marketing institute in Noida, provide complete applications that encompass a huge range of virtual advertising and marketing additives, which includes search engine optimization, virtual communication advertising, pay-per-click on marketing, content material advertising, internet analytics, and greater. These university courses are designed for students who possess a comprehensive understanding of virtual marketing strategies and attributes.Safalta Digital Marketing Institute in Noida is a first choice for young individuals or students who are looking to start their careers in the field of digital advertising. The institute gives specialized courses designed and certification.
for beginners, providing thorough training in areas such as SEO, digital communication marketing, and PPC training in Noida. After finishing the program, students receive the certifications recognised by top different universitie, setting a strong foundation for a successful career in digital marketing.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
Strategies for Effective Upskilling is a presentation by Chinwendu Peace in a Your Skill Boost Masterclass organisation by the Excellence Foundation for South Sudan on 08th and 09th June 2024 from 1 PM to 3 PM on each day.
Executive Directors Chat Leveraging AI for Diversity, Equity, and InclusionTechSoup
Let’s explore the intersection of technology and equity in the final session of our DEI series. Discover how AI tools, like ChatGPT, can be used to support and enhance your nonprofit's DEI initiatives. Participants will gain insights into practical AI applications and get tips for leveraging technology to advance their DEI goals.
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
Thinking of getting a dog? Be aware that breeds like Pit Bulls, Rottweilers, and German Shepherds can be loyal and dangerous. Proper training and socialization are crucial to preventing aggressive behaviors. Ensure safety by understanding their needs and always supervising interactions. Stay safe, and enjoy your furry friends!
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
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Cwe2010 paper 172
1. The Fifth International Symposium on Computational Wind Engineering (CWE2010)
Chapel Hill, North Carolina, USA May 23-27, 2010
On the effects of complex urban geometries in mesocale
modelling
Adil Rasheeda, Darren Robinsona, Djamel Lakehal b
a
EPFL ENAC, Lausanne, Switzerland (adil.rasheed@gmail.com)
b
ASCOMP GmbH, Zurich, Switzerland (lakehal@ascomp.ch)
ABSTRACT:
Urban parameterizations that are developed can be applied to only those urban geometries
which can be represented by a regular array of cubes. However, in a real city we tend to encoun-
ter complex geometries which do not obviously match such simplified ones. Yet all of the urban
parameterizations thus far developed share the assumption that a city is made up either of a regu-
lar array of cubes or of infinitely long canopies. The inputs to these models which include street
width, building width, building density and a statistical representation of the building heights, are
generally obtained through quantitative field surveys or qualitative estimates. But in performing
this geometric abstraction there is no way to ensure that the total built surfaces and volumes of
the simplified geometry match those of the actual city, or more importantly that the energy and
momentum exchanges are equivalent. We aim here to test the hypothesis that cities can be accu-
rately represented by a regular array of cubes or canopies. For this we investigate, for a particular
scenario, the effects of urban complexity on the spatially averaged drag forces and shortwave rad-
iation exchange. We propose a new approach for fitting an array of cubes to any realistic geome-
try, so that new or existing urban parameterization schemes can be used with confidence.
1 INTRODUCTION
Climate has a direct impact on cities’ energy flows due to the space conditioning (heating,
cooling) needs of the buildings accommodated. This impact may be reinforced due to climate
change and to the (so-called) urban heat island (UHI) effect. The corresponding changes in ener-
gy demands alter greenhouse gas emissions so that there is a feedback loop. To be able to simu-
late cities’ metabolism with reasonable accuracy it is thus important to have good models of the
urban climate. But this is complicated by the diverse scales involved. The climate in a city, for
example, will be affected not only by the buildings within the urban canopy (the size of a few
meters) but also by large topographical features such as nearby water bodies or mountains (the
size of a few kilometers). Unfortunately, it is not possible to satisfactorily resolve all of these
scales in a computationally tractable way using a single model. It is because of this that we use a
mesoscale model having a resolution of say 1 km and a domain having a size of up to a few hun-
dred of kilometers. The impact of bigger scales is then forced through the boundary conditions
using results from a Global model while the subgrid scales are parameterized. Such parameteriza-
tions are generally comprised of an Urban Canopy Model and a Building Energy Model.
It is well established that urban structures can modify the local climate: they present drag
forces and generate turbulent wake diffusion and decrease wind speed Roth (2000). Furthermore
buildings produce an intense shear layer at the top of an urban canopy, where mean kinetic ener-
gy is transformed into turbulent kinetic energy. The thermo-physical and hygroscopic properties
of urban structures are such that these tend to be rather dry, so that evaporation-transpiration is
2. The Fifth International Symposium on Computational Wind Engineering (CWE2010)
Chapel Hill, North Carolina, USA May 23-27, 2010
relatively weak. Radiation-absorption in street canyons and heat storage in buildings may also
modify the radiative and energy budget, causing a city to be on average warmer than the sur-
rounding areas. Due to differences in heat capacity urban and rural temperature differences tend
to reach maxima during the night and minima during the day. Many parameterizations have been
developed to account for these effects. However these assume a city to be comprised of a regular
array of parallelepipeds. In this paper we try to investigate the importance of this assumption and
we suggest a procedure for fitting real complex urban geometries to simplified equivalents to im-
prove the predictive accuracy of urban climate models, the details of which can be found in Ra-
sheed et al., (2010).
2 MODELLING BACKGROUND
To accurately model the physics of the urban canopy, new concepts in surface modeling have
been developed. These models aim to solve the surface energy balance (SEB) for a realistic 3D
urban canopy. They share in common the following characteristics in their construction: (i) 3D
building shapes that offer drag to air flow, (ii) separate treatment of roof, wall and street surfaces
from energetic point of view, and (iii) radiative interactions between streets and walls. These
models consist of horizontal and vertical representations of the urban structures. The vertical sur-
faces represent building walls and the horizontal surfaces represent streets and roofs. Since, a
clear distinction between these surfaces is made it is very convenient to assign different values of
thermo-physical parameters to these surfaces and to model them differently. Such simple models
use a highly simplified approach to compute complex radiation exchanges like in the work of
Noiah (2000) which is based on view factors between the different surfaces or facets comprising
the surfaces. Solar reflections and occlusions to sun and the (normally isotropic) sky are also ex-
plicitly resolved. Surface temperatures, energy exchanges with the surrounding and energy sto-
rage in the built material is computed via solving a set of one dimensional conduction equation
for different types of surfaces. These models are broadly classified into two major categories:
Single Layer Urban Canopy Models like the Town Energy Balance (TEB) model of Masson
(2000) and Multilayer Urban Canopy Model like that of Martilli et. al (2002). Almost all multi-
layer urban canopy models (e.g. Kondo, 2005; Martilli, 2002) are mathematically represented by:
∂u ∂ ∂u
= k zm + Qu
∂t ∂x ∂z
∂v ∂ ∂v
= k zm + Qv (1)
∂t ∂x ∂z
∂θ ∂ ∂θ
= k zθ + Qθ
∂t ∂x ∂z
where u and v are the horizontal velocity components and θ is the potential temperature and t is
time. The basic assumption here is that a city is represented by a regular array of cubes (Figure
1), and the terms k zm , k zθ , Qu , Qv , Qθ represent the effects of drag, shear and other sources which
are parameterized in terms of the parameters B1, B2, W1, W2 and street orientation. The term
Qθ represents the energy exchange with the buildings, which depends on the surface tempera-
tures of the wall, ground and roof. The thermo-physical properties of the materials are generally
quite different and hence a differential heating of these surfaces may lead to very different source
terms. This differential heating can be caused due to the different amount of radiation incident on
these different surfaces and the canopy velocity which in turn will be affected by the drag force.
3. The Fifth International Symposium on Computational Wind Engineering (CWE2010)
Chapel Hill, North Carolina, USA May 23-27, 2010
3 TESTING THE HYPOTHESIS
All canopy models need as inputs: street width & orientation, building width, building density
and a statistical representation of building heights which are generally obtained through quantita-
tive field survey (which are very slow and time consuming to perform) or qualitative estimates.
But in performing this geometric abstraction there is no way to ensure that the total built surfaces
and volumes of the simplified geometry match those of the actual city or more importantly that
the energy and momentum exchanges are equivalent. In this section we aim to test the central hy-
pothesis that cities can be accurately represented by a regular array of parallelepipeds. For the
purpose we investigate, for a particular scenario, the effects of complexity in urban geometry on
the spatially averaged drag forces and short wave radiation exchanges with different surfaces
(roofs, ground, and walls). For radiation exchange we use a Simplified Radiosity Algorithm
(SRA) (Robinson and Stone 2004), while for drag computation we employ the Immersed Surface
Technique (IST) (Labois et al., 2010).
Table 1: Geometric characteristics of built surfaces in the domain of interest
Horizontal built area (Roofs) 144,000m2
Vertical built area (Walls) 432,000m2
Horizontal built area (Ground) 606,000m2
Building Height 15m
Total Built Volume 2,160,000m3
Table 2: Building plan area fraction and wall area fraction
Ar (m2) At (m2) Aw (m2) Lp Lw
Long Canopies 150,000 750,000 159,000 0.200 0.21
Simple cuboid 1 144,000 750,000 432,000 0.192 0.57
Simple cuboid 2 144,180 750,000 450,360 0.192 0.60
Real morphology 144,000 750,000 432,000 0.192 0.57
3.1 Test set-up
Figure 1: Computational domain.
We chose a part of the city of Basel (Switzerland), which has a dimension of 1000m by 750m.
A good approximation of the real geometry is sketched and it is assumed that all the buildings
have a uniform height of 15m. Many of the buildings in this part of Basel have been constructed
to this maximum height, although they do not necessarily all have flat roofs. However, our objec-
4. The Fifth International Symposium on Computational Wind Engineering (CWE2010)
Chapel Hill, North Carolina, USA May 23-27, 2010
tive here is not to attempt to reproduce reality. Rather it is to test whether a simplified abstract re-
presentation of urban geometry can be used to reproduce similar energy and momentum ex-
change to its real (complex) counterpart. For this, a simplification of the third dimension of the
geometry should not undermine the relevance of our study. The total built vertical and horizontal
surface areas are presented in Table 1. Three simplified representations are also considered.
These we refer to as long canopies, simple cuboids 1, and simple cuboids 2. The long canopies
representation of the city consists of ten rows of terraced buildings each of dimension 500m ×
30m, with an interspacing of 67m, as shown in Figure 2. Simple cuboids 1 consists of 20 × 18,
cuboids each of dimension 20m × 20m × 15m and aligned in a regular array with a spacing of
30m in the stream wise direction and 20m in the span wise direction (Figure 2). Similarly, the
simple cuboids 2 representation consists of 20×18 cuboids of size 26.7m × 15m × 15m aligned in
a regular array with a spacing of 23.3m in the x direction and 25m in the y direction (Figure 2).
Figure 2: Surface tesselization of geometries.
For clarity we present in Table 2 some associated geometric quantities; the building plan area
fraction and the building wall area fraction. It should be noted that the building plan area fraction
for all the representations under consideration are similar, at about 0.2. However, the wall area
fraction for the long canopy is different compared to other representations. The intention here is
to show that even when the built volume and roof area are kept equal, the vertical wall area can
differ and have a severe impact on radiation exchange and air flow. In reality even basic quanti-
ties like the built volume are hardly conserved. Thus by ensuring the equivalence of these quanti-
ties we focus on testing the underlying hypothesis that real geometries can be modeled with rea-
sonable accuracy by simplified, rather than on errors in geometric (survey) abstraction.
5. The Fifth International Symposium on Computational Wind Engineering (CWE2010)
Chapel Hill, North Carolina, USA May 23-27, 2010
Table 3: Space averaged drag (Fx, Fy) and shear forces (Sx,Sy)
- Fx (N) Fy (N) Sx (N) Sy (N) Fx+Sx (N) Fy+Sy (N)
Complex 8207 157 985 2.5 9194 160
Long Canopies 14093 38.52 1424 1.95 15507 40.5
Simple cuboids 1 4931 -46 754 1.3 5658 -45
Simple cuboids 2 2911 -35 665 -3 3577 -38
3.2 Radiation modeling
Figure 3: Comparison of the amount of shortwave radiation incident on roof (left) and wall (right) surfaces every
hour for the four cases
The magnitude of incident irradiation varies with the type of surfaces (wall, roof and ground;
due to differences in surface tilt, orientation and occlusion). This tends to result in different sur-
face temperatures, which in turn affects the quantity of energy exchanged with the surroundings.
To better understand this problem we investigate in this section the differences in incident irrad-
iation for our simplified geometries of equivalent volume. For radiation computation, the surfaces
in each of the representations are tessellated into smaller surfaces (Figure 2). This simulation was
conducted for the 7th of January. All domains of the same size will have the same quantity of so-
lar radiation entering them. For mesoscale modeling the correct calculation of the distribution of
the radiation amongst the wall, roof and ground surfaces is very important, as this determines the
total absorption of radiation within our domain and the corresponding energy that is transferred to
the adjacent air. Variations in the spatial distribution of absorbed solar energy may also modify
momentum transfers. From Figure 3 we reach the following observations:
• Roofs: Since the horizontal roof surface areas in all the representations are the same and all
the buildings are of the same height we observe that the amount of radiation absorbed dur-
ing the whole day is similar, as expected.
• Ground: In the particular case of long canopies the ground receives more solar radiation
than either of the cuboids layouts, as views to the sun and sky are relatively unobstructed.
In the complex representation these views are relatively obstructed so that the radiation in-
cident on the ground decreases. In the case of the two cuboids representations views are
even further obstructed, so that even less solar radiation is incident on the ground.
• For walls: The two simplified cuboids representations receive more shortwave radiation
than the complex and long canopy representations. This is due to an increased reflected
contribution and an increased south facing surface area. Thus, for this particular day, the
walls in the simplified representation will be warmer than in the complex one. The opposite
will be true for the ground surfaces. This will result in different surface temperatures for
the walls and ground with a corresponding influence on surface energy exchanges.
6. The Fifth International Symposium on Computational Wind Engineering (CWE2010)
Chapel Hill, North Carolina, USA May 23-27, 2010
Figure 4: Velocity field at 5.6m above the ground level
4 COMPUTATIONAL FLUID DYNAMICS
For the CFD simulations the geometrical representation is the same as for the radiation calcula-
tions. However, the domain has been extended at all four boundaries by an additional 200m, to
allow the inflow to develop before encountering urban structures. The domain is discretized into
175 × 175 × 40 cells. For the complex geometry two more simulations were conducted using
150x150x40 and 225x225x60 cells for grid independence; for subsequent simulations a grid of
175 × 175 × 40 was used. An inlet boundary condition with a 1m/s velocity in the flow direction
is imposed. Wall boundary conditions were specified where required. The turbulence model used
is the standard k − ε model; with a 2nd-order convection scheme used velocities. A precondi-
tioned (multigrid) GMRES pressure scheme is used for the pressure field. The flow is converged
in steady state with convergence criteria of E-5 for velocities and kinetic energy and E-3 for dis-
sipation. All the simulations presented in this section are for a neutral atmosphere. In Figure 4 we
present the velocity field for all four geometric representations at a height of 5.6m above the
ground plane. The more complex representation is characterized by the formation of large vortic-
es in the inter-building spaces. There is also a tendency for the flow to be deflected in the span-
wise direction, due to the irregular orientation of the buildings. Long canopies strongly retard the
flow, which tends to stagnate within the canopies. Within the other simplified representations,
vortices are formed on the leeward side of the cuboids, which are small and well isolated from
each other. Also, because these obstructions are non-continuous the fluid motion remains essen-
tially unidirectional in the streamwise direction. These observations are also evident from the
magnitude of the spatially averaged drag forces presented in Table 4.
7. The Fifth International Symposium on Computational Wind Engineering (CWE2010)
Chapel Hill, North Carolina, USA May 23-27, 2010
5 CONCEPT OF EQUIVALENT CITY
Figure 5: Complex geometry reduced to its equivalent simplified form
From the previous section it appears to be clear that the form and layout of buildings of similar
total volume has important implications for the imposed drag forces and the distribution of ab-
sorbed radiant energy, which might lead to differential heating of surfaces and hence to differ-
ences in the total energy exchange with the surrounding air. It is thus important to identify an ar-
rangement of a simplified geometry (as used in urban parameterization scheme) for which these
two quantities (drag and shortwave radiation absorption) are roughly equivalent to those expe-
rienced by the corresponding real geometry. For this purpose we introduce a new technique for
fitting such an equivalent simplified geometry. In this we define an equivalent geometry as “that
geometry which has the same built volume, horizontal and vertical built area, offers the same
drag and absorbs the same shortwave radiation on vertical and horizontal surfaces as the com-
plex/real representation”. To find the equivalent geometry a digitalized 3-D representation is
sketched and parsed to the solver, which then identifies the corresponding equivalent geometry.
The constraints are that the total built surface area and volume of the geometries are equivalent:
Scomplex = S simplified ; and Vcomplex = Vsimplified (2)
where S stands for vertical or horizontal surface area and V stands for total built volume. The ob-
jective functions to be minimized are:
wall wall ground ground
f1 = Radiationcomplex − Radiationsimplified ; f 2 = Radiationcomplex − Radiationsimplified
(3)
f 3 = Drag complex − Drag simplified
Figure 6: Shortwave radiation incident on different surfaces for ground and wall surfaces
8. The Fifth International Symposium on Computational Wind Engineering (CWE2010)
Chapel Hill, North Carolina, USA May 23-27, 2010
After several iterations we have identified a geometry which satisfies our definition of ”equiva-
lent geometry” (Figure 5) for our case study of Basel. We can see from Table 5 that the drag
forces for both geometric models are comparable. Although the forces in the spanwise direction
do differ, their magnitudes compared to the streamwise forces are negligible. Furthermore, from
Figure 6 we see that the profiles of radiation incident on the ground and wall surfaces for the
complex and equivalent representations are now precisely superimposed. The radiation incident
on the roof surfaces is not presented: it is proportional to the horizontal roof surface areas, which
are identical for both representations. Each cube in the equivalent representation has a dimension
of 26.7m×15m×15m. The West-East street width is 23.3m and it is aligned at an angle of 30 de-
grees to the east, while the South-North street width is 25m and is aligned o the other street.
Table 4: Drag, shear and total forces
- Fx (N) Fy (N) Sx (N) Sy (N) Fx+Sx (N) Fy+Sy (N)
Complex 8207 157 985 2.5 9194 160
Equivalent 7731 -346 894 5.8 8625 -340
6 CONCLUSION
A new algorithm has been developed and tested for fitting equivalent urban canopy geometry to
any real complex geometry, based on minimizing the error in drag force and absorbed radiation.
This new method may be used to calibrate the geometric inputs to any urban canopy model in a
rigorous way. It should be noted that in this work we have sketched the geometry of the complex
city using Google earth images and then extruded them to a particular height based on field mea-
surement. However, the algorithm which is explained in this paper can handle non-uniformity in
building height so that with 3-D laser scanned geometries becoming more and more accessible
could in principle further improve the accuracy of our equivalent representation. We have fo-
cused on these two for reasons of parsimony, but further work would be warranted to confirm or
otherwise this hypothesis and in the latter case to select alternative or additional parameters. Fi-
nally, a process of manual trial and error has thus far been employed in fitting our simplified
geometries by minimizing differences in drag and radiation predictions. Subject to computational
constraints the use of evolutionary algorithms would be more appropriate, enabling the available
parameter space to be further explored.
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