Open Access. Powered by Scholars. Published by Universities.®

Other Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 11 of 11

Full-Text Articles in Other Engineering

Lifecycle Energy Consumption Prediction Of Residential Buildings By Incorporating Longitudinal Uncertainties, Endong Wang, Zhigang Shen Oct 2012

Lifecycle Energy Consumption Prediction Of Residential Buildings By Incorporating Longitudinal Uncertainties, Endong Wang, Zhigang Shen

Architectural Engineering -- Faculty Publications

Accurate prediction of buildings’ lifecycle energy consumption is a critical part in lifecycle assessment of residential buildings. Longitudinal variations in building conditions, weather conditions and building’s service life can cause significant deviation of the prediction from the real lifecycle energy consumption. The objective is to improve the accuracy of lifecycle energy consumption prediction by properly modelling the longitudinal variations in residential energy consumption model using Markov chain based stochastic approach. A stochastic Markov model considering longitudinal uncertainties in building condition, degree days, and service life is developed: 1) Building’s service life is estimated through Markov deterioration curve derived ...


Investigating Self-Cooling Effects Of Ventilated Attics Under Different Roof And Ambient Temperatures In Summer, Zhigang Shen, Shimin Wang Sep 2012

Investigating Self-Cooling Effects Of Ventilated Attics Under Different Roof And Ambient Temperatures In Summer, Zhigang Shen, Shimin Wang

Architectural Engineering -- Faculty Publications

An unsteady computational fluid dynamics model is employed to simulate summer-time buoyancy-driven turbulent ventilation in gable-roof attics of residential buildings. The energy performance of vented attics is assessed by comparing their performance to sealed attics with the same geometry and insulation configurations. The simulated boundary conditions of the roof-top temperature ranging between 295.15 K and 345.15 K, coupled with an ambient temperature ranging between 295.15 K and 315.15 K, resemble the summer attic conditions with effects of solar irradiance on the roofs. Simulation results indicate that both the vented and sealed attics are dominated by thermal ...


A Composite Structural Steel And Prestressed Concrete Beam For Building Floor Systems, Nathan Dewit Apr 2012

A Composite Structural Steel And Prestressed Concrete Beam For Building Floor Systems, Nathan Dewit

Architectural Engineering -- Dissertations and Student Research

Precast prestressed concrete beams, such as rectangular and inverted tee beam, currently used in residential and commercial buildings are deep, heavy, and limited to span-to-depth ratios of 15. The research proposes a composite structural steel and prestressed concrete beam that is shallow, light, easy to produce and erect, and able to achieve a span-to-depth ratio of 24. The proposed beam is designed to be used with precast columns, hollow-core planks, and a cast-in-place topping to create a moment-resisting floor system that minimizes the need for shear walls. The goal of this system is to eliminate as many of the limitations ...


Impacts Of Ventilation Ratio And Vent Balance On Cooling Load And Air Flow Of Naturally Ventilated Attics, Shimin Wang, Zhigang Shen Jan 2012

Impacts Of Ventilation Ratio And Vent Balance On Cooling Load And Air Flow Of Naturally Ventilated Attics, Shimin Wang, Zhigang Shen

Architectural Engineering -- Faculty Publications

The impacts of ventilation ratio and vent balance on cooling load and air flow of naturally ventilated attics are studied in this paper using an unsteady computational fluid dynamics (CFD) model. Buoyancy-driven turbulent ventilations in attics of gable-roof residential buildings are simulated for typical summer conditions. Ventilation ratios from 1/400 to 1/25 combined with both balanced and unbalanced vent configurations are investigated. The modeling results show that the air flows in the attics are steady and exhibit a general streamline pattern that is qualitatively insensitive to the variations in ventilation ratio and vent configuration. The predicted temperature fields ...


Effects Of Roof Pitch On Air Flow And Heating Load Of Sealed And Vented Attics For Gable-Roof Residential Buildings, Shimin Wang, Zhigang Shen Jan 2012

Effects Of Roof Pitch On Air Flow And Heating Load Of Sealed And Vented Attics For Gable-Roof Residential Buildings, Shimin Wang, Zhigang Shen

Architectural Engineering -- Faculty Publications

Pitch value is an important consideration in residential gable roof design and construction. However, how roof pitch, coupled with air flows in attic space, affects the energy performance of building attics has been barely investigated. In this paper, a 2D unsteady computational fluid dynamics (CFD) model is employed to investigate the effects of roof pitch on air flow and heating load of both sealed and vented attics for gable-roof residential buildings. The simulation results show that air flow in the sealed attics is steady and asymmetric, while that in the vented attics is a combination of an essentially symmetric base ...


The Impact Of Roof Pitch And Ceiling Insulation On Cooling Load Of Naturally-Ventilated Attics, Shimin Wang, Zhigang Shen, Linxia Gu Jan 2012

The Impact Of Roof Pitch And Ceiling Insulation On Cooling Load Of Naturally-Ventilated Attics, Shimin Wang, Zhigang Shen, Linxia Gu

Architectural Engineering -- Faculty Publications

A 2D unsteady computational fluid dynamics (CFD) model is employed to simulate buoyancy-driven turbulent ventilation in attics with different pitch values and ceiling insulation levels under summer conditions. The impacts of roof pitch and ceiling insulation on the cooling load of gable-roof residential buildings are investigated based on the simulation of turbulent air flow and natural convection heat transfer in attic spaces with roof pitches from 3/12 to 18/12 combined with ceiling insulation levels from R-1.2 to R-40. The modeling results show that the air flows in the attics are steady and exhibit a general streamline pattern ...


Teaching Sustainable Design Using Bim And Project-Based Energy Simulations, Zhigang Shen, Wayne Jensen, Tim Wentz, Bruce Fischer Jan 2012

Teaching Sustainable Design Using Bim And Project-Based Energy Simulations, Zhigang Shen, Wayne Jensen, Tim Wentz, Bruce Fischer

Architectural Engineering -- Faculty Publications

The cross-disciplinary nature of energy-efficient building design has created many challenges for architecture, engineering and construction instructors. One of the technical challenges in teaching sustainable building design is enabling students to quantitatively understand how different building designs affect a building’s energy performance. Concept based instructional methods fall short in evaluating the impact of different design choices on a buildings’ energy consumption. Building Information Modeling (BIM) with energy performance software provides a feasible tool to evaluate building design parameters. One notable advantage of this tool is its ability to couple 3D visualization of the structure with energy performance analysis without ...


Development And Evaluation Of A Simplified Modeling Approach For Hydraulic Systems, Yuebin Yu, Vivian Loftness, Daihong Yu, Yan Lu, Volker Hartkopf Jan 2012

Development And Evaluation Of A Simplified Modeling Approach For Hydraulic Systems, Yuebin Yu, Vivian Loftness, Daihong Yu, Yan Lu, Volker Hartkopf

Architectural Engineering -- Faculty Publications

This paper presents how a hydraulic system can be properly modeled for hydraulic balancing, knowledge of flow distribution, coupled simulation, and evaluation of control, etc. It focuses on water-based heating and cooling systems, which generally have high energy efficiency in design but could perform poorly in reality due to the undersensing condition and strong thermal-hydraulic coupling. The study introduces the motivation, presents the simplified modeling methodology, and illustrates the model and simulating structure. A preliminary evaluation of the method is conducted with two simple simulations. The proposed “node-branch-state” modeling approach could be easily modified, expanded and integrated into a detailed ...


Application Of Drum-Buffer-Rope Methodology In Scheduling Of Healthcare System, Arefeh Mohammadi, Emmanuel S. Eneyo Jan 2012

Application Of Drum-Buffer-Rope Methodology In Scheduling Of Healthcare System, Arefeh Mohammadi, Emmanuel S. Eneyo

Architectural Engineering -- Faculty Publications

Theory of constraints (TOC) is a management philosophy that seeks to increase throughput (efficiency or performance) of the system by identifying those processes that are constraining the system bottlenecks. There have been very few profound studies of TOC in health care systems. In order to fill this gap, this study was conducted to determine how healthcare systems are utilizing components of TOC to schedule operations and what results are being obtained. This is done by using a patient flow model for a radiotherapy section of a hospital. The drum-buffer-rope (DBR) was used as the methodology for scheduling this flow. Successful ...


Effects Of Inclusion Shapes Within Rigid Porous Materials On Acoustic Performance, Hyun Hong, Siu-Kit Lau Jan 2012

Effects Of Inclusion Shapes Within Rigid Porous Materials On Acoustic Performance, Hyun Hong, Siu-Kit Lau

Architectural Engineering -- Faculty Publications

The present study investigates the influence of various shapes of inclusions having same volume embedded in a porous rigid material. Previous studies showed improvement of the broadband sound absorption with particular shapes of inclusions. However, different volumes of the inclusions have been considered; therefore, the bulk densities are not the same for comparison. The present study extends the investigations of inclusions in porous materials with same volume (or bulk density) to eliminate the influence by the change of bulk density. The effects of shape will be discussed. Finite element modeling will be used for this study. Total four different shapes ...


A Directionally Tunable But Frequency-Invariant Beamformer On An Acoustic Velocity-Sensor Triad To Enhance Speech Perception, Yue Ivan Wu, Kainam Thomas Wong, Xin Yuan, Siu-Kit Lau, Shiu-Keung Tang Jan 2012

A Directionally Tunable But Frequency-Invariant Beamformer On An Acoustic Velocity-Sensor Triad To Enhance Speech Perception, Yue Ivan Wu, Kainam Thomas Wong, Xin Yuan, Siu-Kit Lau, Shiu-Keung Tang

Architectural Engineering -- Faculty Publications

Herein investigated are computationally simple microphone-array beamformers that are independent of the frequency-spectra of all signals, all interference, and all noises. These beamformers allow the listener to tune the desired azimuth-elevation “look direction.” No prior information is needed of the interference. These beamformers deploy a physically compact triad of three collocated but orthogonally oriented velocity sensors. These proposed schemes’ efficacy is verified by a jury test, using simulated data constructed with Mandarin Chinese (a.k.a. Putonghua) speech samples. For example, a desired speech signal, originally at a very adverse signal-to-interference-and-noise power ratio (SINR) of -30 dB, may be processed ...