scholarly journals A Review of Some Recent Studies on Buoyancy Driven Flows in an Urban Environment

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Bodhisatta Hajra
Keyword(s):  
Natural Convection ◽  
Water Channel ◽  
Field Measurements ◽  
Design Guidelines ◽  
Future Research ◽  
Channel Measurements ◽  
Cfd Modelling ◽  
Pollution Levels ◽  
Buoyancy Driven Flows ◽  
Building Walls

This paper reviews some recent studies (after 2000) pertaining to buoyancy driven flows in nature and thier use in reducing air pollution levels in a city (city ventilation). Natural convection flows occur due to the heating and cooling of various urban surfaces (e.g., mountain slopes), leading to upslope and downslope flows. Such flows can have a significant effect on city ventilation which has been the subject of study in the recent times due to increased pollution levels in a city. A major portion of the research reviewed here consists of natural convection flows occurring along mountain slopes, with a few studies devoted to flows along building walls. The studies discussed here primarily include field measurements and computational fluid dynamics (CFD) models. This review shows that for densely populated cities with high pollution levels, natural convection flows (mountain slope or building walls) can significantly aid the dispersion of pollutants. Additional studies in this area using CFD and water channel measurements can explain the physical processes involved in such flows and help improve CFD modelling. Future research should focus on a complete understanding of the mechanisms of buoyancy flows in nature and developing design guidelines for better planning of cities.

Grid-Free Vortex Methods for Natural Convection in Two-Dimensional Domains

2012 ◽  
Author(s):  
Issam Lakkis
Keyword(s):  
Natural Convection ◽  
Nonlinear Diffusion ◽  
Reacting Flows ◽  
Ideal Gas ◽  
Two Dimensional ◽  
Vortex Methods ◽  
Free Vortex ◽  
Low Mach Number ◽  
Buoyancy Driven Flows ◽  
Vorticity Generation

Vortex methods for simulating natural convection of an ideal gas in unbounded two-dimensional domains are presented. In particular, the redistribution method for diffusion is extended to enable simulation of nonlinear diffusion of an ideal gas in isobaric conditions encountered in unbounded low-Mach number flows. We also address the problem of handling source terms in grid-free vortex methods and propose a fast, accurate, and physically motivated method for solving the associated inverse problems. Examples include generation of baroclinic vorticity in non-reacting buoyancy driven flows, and in addition, generation of internal energy and species in buoyant reacting flows. Accuracy and speed of the proposed algorithms for nonlinear diffusion and vorticity generation are investigated separately. Simulations of natural convection of a “thermal patch” for Grashof number ranging from to 1562.5 to 25000 are presented.

scholarly journals NLOS Path Loss Model for Low-Height Antenna Links in High-Rise Urban Street Grid Environments

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Juyul Lee ◽  
Myung-Don Kim ◽  
Hyun Kyu Chung ◽  
Jinup Kim
Keyword(s):  
Path Loss ◽  
Field Measurements ◽  
Propagation Path ◽  
Delay Spread ◽  
Communication Link ◽  
Channel Measurements ◽  
Loss Model ◽  
Path Loss Model ◽  
Power Delay Profile ◽  
High Rise

This paper presents a NLOS (non-line-of-sight) path loss model for low-height antenna links in rectangular street grids to account for typical D2D (device-to-device) communication link situations in high-rise urban outdoor environments. From wideband propagation channel measurements collected in Seoul City at 3.7 GHz, we observed distinctive power delay profile behaviors between 1-Turn and 2-Turn NLOS links: the 2-Turn NLOS has a wider delay spread. This can be explained by employing the idea that the 2-Turn NLOS has multiple propagation paths along the various street roads from TX to RX, whereas the 1-Turn NLOS has a single dominant propagation path from TX to RX. Considering this, we develop a path loss model encompassing 1-Turn and 2-Turn NLOS links with separate scattering and diffraction parameters for the first and the second corners, based on the Uniform Geometrical Theory of Diffraction. In addition, we consider the effect of building heights on path loss by incorporating an adjustable “waveguide effect” parameter; that is, higher building alleys provide better propagation environments. When compared with field measurements, the predictions are in agreement.

scholarly journals Double P! Public Spaces in Dubai: a Paranoiac Panopticon

2020 ◽  
pp. 247-262
Author(s):  
Therese Chidiac
Keyword(s):  
Public Space ◽  
Free Market ◽  
Public Spaces ◽  
Design Guidelines ◽  
Future Research ◽  
Cultural Images ◽  
Human Scale ◽  
Free Market Capitalism ◽  
Back Stage ◽  
The City

Despite the crisis of the metaphoric growth of its superficiality to its deadening sterility, Dubai stands as an attractive destination in the desert simulating a collage of cultural images from around the world with a centrally-planned free market capitalism attracting investors and developers. This paper is part of my master in architecture thesis at Politecnico di Milano titled: 5km/hr Manifesto and it outlines the problematical aspect of Dubai DNA: Dubai public spaces. The city is metaphorically analysed, as a collage city of exogenous fragments and a system city resembling a biological cell with defects in it’s the so-called public spaces that are designed as a model of a virtual panopticon of social surveillance forged by a set of do’s and don’ts. Built up rapidly over the past few years on the wealth gotten from oil, public spaces in Dubai have no depth of history or indigenous culture, no complexity, no conflicts, no doubts, nothing to stand in the way of its being shaped into the ultimate wonderland. The Arab notion of public has been dramatically ignored in the planning of the city and has been replaced with a collage of regulated western modernist spaces that have failed to create pockets of interaction and communication bringing in mind a problematical situation and an utopic question: How to demystify the panopticon effect and make Dubai more liveable? This leads to the recall of the qualities of the endogenous Arabic Public Space: The Souk. A set of characteristics has been concluded and if integrated, might really change Dubai public spaces from a paranoic panopticon to a more liveable space. Enclosure and privacy, human scale and density, the stage and back stage effect were essential conditions in the souk and are elaborated in this paper presenting a set of new design guidelines for claiming back what is supposed to be public and might develop into further future research.

Augmented Reality in Informal Learning Settings

2018 ◽  
pp. 804-825
Author(s):  
Eric G. Poitras ◽  
Jason M. Harley ◽  
Timothy Compeau ◽  
Kevin Kee ◽  
Susanne P. Lajoie
Keyword(s):  
Augmented Reality ◽  
Cultural Heritage ◽  
Informal Learning ◽  
Case Studies ◽  
Learning Environments ◽  
Role Playing ◽  
Design Guidelines ◽  
Future Research ◽  
Heritage Sites ◽  
Important Challenge

Cultural heritage sites and museums are faced with an important challenge – how best to balance the needs of engaging visitors in meaningful and entertaining experiences, while at the same time exploiting the affordances of exhibits for instructional purposes. In this chapter, we examine the use of augmented reality in the context of informal learning environments, and how this type of technology can be used as a means to enhance learning about history. The research case studies are reviewed in terms of the use of historical locations, experience mechanics, narrative/plot, and role-playing (the later two representing game-based elements) in the design guidelines of instructional activities and applications (Dunleavy & Dede, 2014). In doing so, we critique the theoretical, methodological, and instructional underpinnings of studies that evaluate augmented reality applications and draw several recommendations for future research in this field.

Augmented Reality in Informal Learning Settings

2017 ◽  
pp. 272-293 ◽  
Author(s):  
Eric G. Poitras ◽  
Jason M. Harley ◽  
Timothy Compeau ◽  
Kevin Kee ◽  
Susanne P. Lajoie
Keyword(s):  
Augmented Reality ◽  
Cultural Heritage ◽  
Informal Learning ◽  
Case Studies ◽  
Learning Environments ◽  
Role Playing ◽  
Design Guidelines ◽  
Future Research ◽  
Heritage Sites ◽  
Important Challenge

Cultural heritage sites and museums are faced with an important challenge – how best to balance the needs of engaging visitors in meaningful and entertaining experiences, while at the same time exploiting the affordances of exhibits for instructional purposes. In this chapter, we examine the use of augmented reality in the context of informal learning environments, and how this type of technology can be used as a means to enhance learning about history. The research case studies are reviewed in terms of the use of historical locations, experience mechanics, narrative/plot, and role-playing (the later two representing game-based elements) in the design guidelines of instructional activities and applications (Dunleavy & Dede, 2014). In doing so, we critique the theoretical, methodological, and instructional underpinnings of studies that evaluate augmented reality applications and draw several recommendations for future research in this field.

A Multimodal Interaction Design Guidelines for VR Foot Reflexology Therapy Application

2016 ◽  
Vol 7 (3) ◽  
pp. 74-91
Author(s):  
Hector Chimeremeze Okere ◽  
Suziah Sulaiman ◽  
Dayang Rohaya Awang Rambli ◽  
Oi-Mean Foong
Keyword(s):  
Interaction Design ◽  
Multimodal Interaction ◽  
Stress Relief ◽  
Structured Interview ◽  
Design Guidelines ◽  
Future Research ◽  
Art And Culture ◽  
Interactive Nature ◽  
Design Requirements ◽  
Stress Therapy

The proliferation of multimodal interaction research have presented numerous advantages which include enhancement of realism, increased efficiency in user task performance and the achievement of an interactivity that is relatively identical to the conventional human to human interactions. Haptic, visual, and aural interactions have been widely utilized and applied in various domains ranging from military and scientific visualization realms into more multidisciplinary areas, such as art and culture, education, archeology, and complementary medicine. In Virtual reality stress therapy application particularly in the proliferation towards the virtualization and simulation of the traditional foot reflexology therapy, little is understood on the haptic, visual and aural interactive nature of the therapy and to what extent they contribute in the patients' relaxation and stress relief, which hinders the system developers from obtaining the appropriate system design requirements for foot reflexology virtual stress therapy applications. This paper presents an exploratory study that examines from both the patients' and practitioners' perspective, the haptic, visual and aural interactive nature in foot reflexology domain since the practices promote relaxation and stress relief. The study explored 2 traditional foot reflexology sessions; audio recorded semi-structured interview was used to collect data from the participant's while the session was going on for analysis. The study findings presented the haptic, visual and aural interactive nature involved from the patients' and practitioners' perspective, and a higher level design requirements for the haptic, aural, visual and general interactivity extracted from the study findings as well as from literature. Implications for future research are also discussed.

scholarly journals SOCIAL NETWORK BY ENVIRONMENTAL DESIGN: FACILITATING THERAPEUTIC EFFECT IN LTCF FOR PEOPLE EXPERIENCING DEMENTIA

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S462-S462
Author(s):  
Farhana Ferdous
Keyword(s):  
Social Network ◽  
Physical Environment ◽  
Spatial Configuration ◽  
Environmental Design ◽  
Design Guidelines ◽  
Future Research ◽  
Positive Health ◽  
Term Care ◽  
Care Facilities ◽  
Environmental Gerontology

Abstract The relationship between the physical environment and the prevalence of social interaction have been a core topic of inquiry in environmental gerontology. It has been estimated that around 25 million people worldwide have dementia, and the number will exceed 80 million by 2040. A growing body of literature in the areas of environment-behavior studies shows that the physical environment affects positive behavioral changes, in turn, affecting individual, group and organizational outcomes, but little research has focused on older adults especially those with cognitive impairment by targeting the Dementia Enabling Environment of care facilities. By using non-pharmacological interventions, the purpose of this study is to initiate positive social network among dementia residents and staff by analyzing the spatial configuration of the physical environment and layout in long-term care facilities (LTCF). The findings may give evidence-based design guidelines for future research and design of memory care facilities to promote therapeutic experience for older people experiencing early to moderate stage dementia. Using a 3-stage, multi-method research design such as space syntax, behavior mapping techniques and direct observations, this study objectively measured the spatial configuration of LTCF (physical environment) to evaluate the provision of social interactions (among dementia residents and staff), promote positive health outcomes and healthy living for people experiencing early to moderate stage dementia. This study was able to establish that the architectural layout and environmental design could have a positive and protective effect against dementia in environmental gerontology and geriatrics.

Analysis of Particle Image Velocimetry Measurements of Natural Convection in an Enclosure Using Proper Orthogonal Decomposition

2015 ◽  
Vol 137 (12) ◽  
Author(s):  
Nirmalendu Biswas ◽  
Souvick Chatterjee ◽  
Mithun Das ◽  
Amlan Garai ◽  
Prokash C. Roy ◽  
...  
Keyword(s):  
Particle Image Velocimetry ◽  
Natural Convection ◽  
Velocity Field ◽  
Proper Orthogonal Decomposition ◽  
Particle Image ◽  
Field Measurements ◽  
Orthogonal Decomposition ◽  
Image Velocimetry ◽  
Low Dimensional ◽  
Proper Orthogonal

This work investigates natural convection in an enclosure with localized heating on the bottom wall with a flushed or protruded heat source and cooled on the top and the side walls. Velocity field measurements are done by using 2D particle image velocimetry (PIV) technique. Proper orthogonal decomposition (POD) has been used to create low dimensional approximations of the system for predicting the flow structures. The POD-based analysis reveals the modal structure of the flow field and also allows reconstruction of velocity field at conditions other than those used in PIV study.

Velocity Field Measurements in Leading Edge Wing Compartments

2008 ◽  
Author(s):  
V. Egan ◽  
D. T. Newport ◽  
V. Larcarac ◽  
B. Estebe
Keyword(s):  
Natural Convection ◽  
Leading Edge ◽  
Field Measurements ◽  
Dominant Mode ◽  
Fluid Temperature ◽  
Velocity Measurements ◽  
Thermal Boundary Conditions ◽  
Single Compartment ◽  
Image Velocimetry ◽  
Convection Cooling

For many applications the optimisation of natural convection cooling is a major design consideration due to factors such as weight, accessibility, cost and power consumption. In aircraft wing compartments, natural convection is the dominant mode of heat transfer due to high wall temperatures resulting from solar loading and heat dissipating internal electronics. This paper investigates the flow structures in a leading edge compartment subject to various thermal boundary conditions. The experimental configuration consisted of two leading edge enclosures; the first is a single compartment while the second has an attached wing box. Particle image velocimetry (PIV) was employed to obtain velocity measurements of the flow in both leading edge enclosures. The second compartment investigated the effect of an adjacent fluid filled enclosure on the flow regime in the leading edge compartment. Higher local velocities were found in the second compartment due to an increase in buoyancy forces resulting from a lower of the average fluid temperature within the compartment. The introduction of a heat dissipating component gave rise to two separate convection structures and in general increased the fluctuations in the both temperature and velocities within the compartment.

scholarly journals Postural Risks and User Experience of 3D Interface Designs for Virtual Reality-based Learning Environments

2019 ◽  
Vol 63 (1) ◽  
pp. 2313-2317 ◽  
Author(s):  
Yilu Sun ◽  
Gourab Kar ◽  
Andrea Stevenson Won ◽  
Alan Hedge
Keyword(s):  
Virtual Reality ◽  
Learning Environments ◽  
User Experience ◽  
Interface Design ◽  
Design Guidelines ◽  
Future Research ◽  
Task Completion ◽  
Significant Difference ◽  
Medium Level ◽  
Interface Designs

Virtual Reality-based Learning Environments (VRLEs) are an emerging tool for classroom teaching. While VRLEs are increasingly in use, little attention has been paid to ergonomic challenges in use of VRLEs. This study compared two 3D interface designs of a VRLE created to teach the phases of the Moon. Participants ( N = 16) were randomly assigned to either a Hand or Toggle interface design. The interface designs were compared in terms of postural risk (REBA score), task completion time, user experience and environmental presence. Results indicate no significant difference between the Hand and Toggle interface designs for the outcome variables; however, environmental presence was marginally higher in the Hand interface. REBA scores for Hand (3.56 ± 0.89) and Toggle (3.79 ± 1.14) indicate low to medium level of postural risks. Future research should focus on development of 3D interface design guidelines to ensure safe, comfortable and effective use of VRLEs.

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