A simplified model of the thermal interaction of a Venetian blind located on the indoor glazing surface of a window

Derek Roeleveld, Ryerson University

Date of Award

2007

Degree Type

Thesis

Degree Name

Master of Applied Science (MASc)

Department

Mechanical Engineering

First Advisor

David Naylor

Abstract

A simplified model was developed to predict the radiative and convective heat transfer in complex fenestration systems, including the effect of solar radiation. The focus of the current work was on Venetian blinds mounted adjacent to the indoor window surface. From the perspective of convection, the model used a convective flat plate flow between the blind and ambient surroundings and a convective channel flow between the window and blinds. It was necessary to develop new empirical correlations to predict the average channel Nusslet numbers of the hot and cold walls separately.

Therefore, a CFG study of free convection in an asymmetrically heated channel was performed. Then, the new empirical correlations were used to develop a simplified one-dimensional model of the heat transfer in the system. The radiative heat exchange between the blind, window and room was calculated using a four surface grey-diffuse model. Sample predicted results were compared with existing experimental and numerical data from the literature.

An experimental study of soil thermal conductivity using a guarded hot plate apparatus

Ivan Nikolaev, Ryerson University

Date of Award

2007

Degree Type

Thesis

Degree Name

Master of Applied Science (MASc)

Department

Mechanical Engineering

Abstract

A guarded hot plate apparatus was used to generate comprehensive sets of thermal conductivity for two types of soils, namely Ottawa sand and Richmon Hill clay-loam, for temperature variation from 2 to 92°C and moisture content variation from complete dryness to full saturation with measurement errors of less than 3%. Numerical simulation of heat transfer within the apparatus with sample inside was performed to validate the experimental design and setup. To prepare the samples, a consistent specimen preparation technique was developed for the cases of dry, barely-to-moderately moist, and highly-to-fully saturated moist soils.

On the basis of gathered datasets, empirical correlations for soil thermal conductivity were developed as a function of both temperature and moisture content. The proposed correlations produced excellent fit to majority of the experimental data, and could be easily integrated into numerical analysis of underground heat transfer. As an application example, one of the correlations was employed to evaluate soil thermal conductivity in a numerical study of underground heat loss from a basement wall and floor, in order to illustrate the importance of considering the dependence of soil thermal conductivity on soil texture, temperature and degree of saturation.

A fatigue damage model developed based on stiffness degradation in human Haversian cortical bone

Hossein Najmi, Ryerson University

Date of Award

2007

Degree Type

Thesis

Degree Name

Master of Applied Science (MASc)

Department

Mechanical Engineering

First Advisor

A Varvani-Farahani

Abstract

The present study intends to develop a fatigue damage model to assess the fatigue response of human cortical bone by incorporating stiffness degradation of bone materials as the number of loading cycles progresses. The proposed fatigue damage model is defined based on mechanical properties and biological parameters of human cortical bone subjected to repeated loads. Stiffness loss in bone and bone constituents was used as a damage index to model the response of fatigue damage. The proposed damage model in this thesis considered bone as a natural composite material consisting of Haversian osteons (fibres) embedded in interstitial bone (matrix) and separated by weak cement-line intrfaces.

Predicted fatigue damage results were found in good agreement with many experimentally obtained damage results of human cortical bone. The proposed damage equation also showed a higher degree of success in damage assessment of cortical bone samples tested by different laboratories as compared to other earlier developed damage models.

The proposed damage model, for the first time, successfully correlated the mechanical and histological properties of human cortical bone with damage accumulation of bone constituents. These parameters represent mechanical and histological properties of cortical bone specimens such as osteon volume fraction, donor age, cyclic stress magnitude, secant modulus of osteons, cement line interfacial strength and other bone constituent mechanical properties.

A computer program was also developed to assess fatigue damage of cortical bone by the proposed damage model and evaluate the proposed model with experimental data extracted from the literature.

Module-based kinetostatic analysis and optimization of a modular reconfigurable robot

Richard P. Mohamed, Ryerson University

Date of Award

2007

Degree Type

Thesis

Degree Name

Master of Applied Science (MASc)

Department

Mechanical Engineering

First Advisor

Jeff Xi

Second Advisor

Guangjun Liu

Abstract

n this thesis, a newly developed kinetostatic model for modular reconfigurable robots (MRRs) is presented. First, a kinetmatic computational method was created to allow for simple connectivity between modules which included the possibilities of angular offsets. Then, a flexibility analysis was performed to determine the static and dynamic flexibility of link and join modules and the regions of flexibility were plotted to determine exactly which of the components can be considered flexible or rigid,

depending on their sizes. Afterwards, the kinetostatic model was developed and compared to a finite element model and results give essentially the same tip deflections between the two models. This kinetostatic model was then used to determine the maximum allowable payload and maximum deflection position for a given MRR. Additionally, a direct method was created to determine the cross section properties of all modules in a given MRR for a given payload and maximum desirable tip deflection.

Three-dimensional modelling of ground surfaces

Ming Li, Ryerson University

Date of Award

2007

Degree Type

Thesis

Degree Name

Master of Applied Science (MASc)

Department

Mechanical Engineering

First Advisor

Ahmad Ghasempor

Second Advisor

Jeff Xi

Abstract

The efficiency and quality of abrasive machining processes influence costs and quality of elements produced, as well as whole products. Hence, the estimation of surface characteristics can greatly facilitate the requirements of performance evaluation. But the surface finish is dominated by many factors and physical model which could predict it is not practical. Therefore, it is very important to develop modelling techniques for the reliable prediction of surface characteristics.

This thesis describes the development of a three-dimensional predictive modellling methodology for surface characteristics of a ground surface. The methodology uses solid modelers to generate the chips and remove them from the solid model of the workpiece. This results in surface model which represents the groud surface in three dimensions. Various surface characteristics can then be deducted from this model.

The modelling of individual abrasive grains follows a statistical distribution which depends on the grinding tool characteristics. The cutting path depends on the relative motion between the tool and workpiece.

The methodology was implemented for three different types of tool path. The results are in agreement with expected values.

A quasi-2D finite element formulation of active constrained-layer functionally graded beam

Elena Miroshnichenko, Ryerson University

Date of Award

2007

Degree Type

Thesis

Degree Name

Master of Applied Science (MASc)

Department

Mechanical Engineering

First Advisor

Donatus Oguamanam

Abstract

A functionally graded (FG) beam with an active constrained-layer damping (ACLD) treatment is modeled and analyzed. ACLD consists of a passive element, in the form of a viscoelastic layer bonded to the host structure, and an active constraining element which is represented by a piezoelectric fiber-reinforced composite (PFRC) laminate. It is assumed in the current formulation that the field variables are expressible as polynomials through the thickness of the beam and are cubically interpolated across the span. Hamilton's principle is used in the derivation of the equations of motion,

which are solved using the Newmark time-integration method. The versatility of the formulation is demonstrated using different support mechanisms in the form of analysis of cantilevered, fixed-end partially-constrained and simply-supported beam cases. The effects of ply orientation in PFRC laminate and varying elastic modulus in the FG beam are also examined.

LEED Canada energy performance modelling of a medical office building using Carrier HAP and NRCan EE4

Ali Nouman Saeed Khan, Ryerson University

Date of Award

2007

Degree Type

Thesis Project

Degree Name

Master of Engineering (MEng)

Department

Mechanical Engineering

First Advisor

Alan Fung

Abstract

The specific goal of this project is to model the energy performance of a medical office building in Carrier HAP and NRCan EE4 simulation software in order to qualify for LEED Canada energy and atmosphere perquisite 2 and credit 1. LEED Canada requires that to be eligible for EAp2 and EAc1, the proposed building must be 25% more energy efficient than a reference building which is designed according to Model National Energy Code for Buildings (MNECB).

The demise of EE4 has created a demanding need to look for substitute software. One of the tasks of the project is to analyze HAP for EAp2 and EAc1 compliance process. EE4 generates the MNECB reference building itself but in HAP the reference building has to be modelled manually. The results from HAP and EE4 show that energy savings are 39.10% and 38.31% respectively with respect to MNECB reference building.