Thermal Tectonics

<p><b>This thesis examines high performance architectural tectonics through theoretical studies, design experiments, and through the design of two case study houses in Christchurch, New Zealand. The thesis focused on formulating a theoretical framework for a practice-focused, environmentally sustainable architecture by studying three key themes, specifically Architectural Tectonics, Contemporary Residential Architecture Detailing, and Energy Efficient Envelope Design.</b></p> <p>The integration of these three fields was undertaken to address the role of architectural design as the construction industry transitions to a net- zero carbon emissions future.</p> <p>Thermal tectonics takes a critical position towards the contemporary approach to residential architectural detailing, which increasingly intensifies the divergence between the tectonic expression of architectural junctions and the performance considerations of energy efficient envelope construction. This divergence results from a number of factors, including the increasing complexity of construction methods, the growing specialisation of building trades, and the increasing specialisation of architectural design.</p> <p>The project aims to tilt the existing aesthetic traditions of New Zealand residential architecture towards a language that performs better thermally. The thermal tectonic approach to architectural design intends to re-integrate the tectonic and performance considerations of the external envelope through a system-based approach to architectural design.</p> <p>Two case-study homes are developed through a tectonic framework that highlights the expressive potential of high performance construction systems. ‘Four Peaks House’ seeks to align a prefabricated SIP system with the vernacular typology of the Bach, developing a detail language that connects the building to place without the need for extensive low-performing glazing. ‘Gallery House’ explores the novel material of Hempcrete, demonstrating how exposing insulative materials can produce rich interior spaces.</p> <p>The design research was conducted through a series of design-led experiments focused on the six key principles of the Thermal Tectonic framework; anatomy, tectonic-stereotomic, space, place, detail and intersection, representation and ornamentation.</p> <p>This approach creates an explicit relationship between building elements and their thermal function, by using thermal simulation software to generate tectonic diagrams that describe how building elements are configured to express the thermal performance of a building. This provides architects with a critical tool for understanding how their design decisions can impact energy efficiency, while also allowing them to make design judgments that prioritise other factors such as aesthetic or material concerns. In addition, the research outcomes provide a direction for sustainable future practice that will ensure architectural ideas are translated into the high-performing language of our future built environment.</p>

A Study on the Electromagnetic–Thermal Coupling Effect of Cross-Slot Frequency Selective Surface

In high-power microwave applications, the electromagnetic-thermal effect of frequency selective surface (FSS) cannot be ignored. In this paper, the electromagnetic-thermal coupling effects of cross-slot FSS were studied. We used an equivalent circuit method and CST software to analyze the electromagnetic characteristics of cross-slot FSS. Then, we used multi-field simulation software COMSOL Multiphysics to study the thermal effect of the FSSs. To verify the simulation results, we used a horn antenna with a power of 20 W to radiate the FSSs and obtain the stable temperature distribution of the FSSs. By using simulations and experiments, it is found that the maximum temperature of the cross-slot FSS appears in the middle of the cross slot. It is also found that the FSS with a narrow slot has severer thermal effect than that with a wide slot. In addition, the effects of different incident angles on the temperature variation of FSS under TE and TM polarization were also studied. It is found that in TE polarization, with the increase in incident angle, the maximum stable temperature of FSS increases gradually. In TM polarization, with the increase in incident angle, the maximum stable temperature of FSS decreases gradually.

Performance Enhancement of Optimized Link State Routing Protocol by Parameter Configuration for UANET

The growing need for wireless communication has resulted in the widespread usage of unmanned aerial vehicles (UAVs) in a variety of applications. Designing a routing protocol for UAVs is paramount as well as challenging due to its dynamic attributes. The difficulty stems from features other than mobile ad hoc networks (MANET), such as aerial mobility in 3D space and frequently changing topology. This paper analyzes the performance of four topology-based routing protocols, dynamic source routing (DSR), ad hoc on-demand distance vector (AODV), geographic routing protocol (GRP), and optimized link state routing (OLSR), by using practical simulation software OPNET 14.5. Performance evaluation carries out various metrics such as throughput, delay, and data drop rate. Moreover, the performance of the OLSR routing protocol is enhanced and named “E-OLSR” by tuning parameters and reducing holding time. The optimized E-OLSR settings provide better performance than the conventional request for comments (RFC 3626) in the experiment, making it suitable for use in UAV ad hoc network (UANET) environments. Simulation results indicate the proposed E-OLSR outperforms the existing OLSR and achieves supremacy over other protocols mentioned in this paper.

A Novel Approach to Reservoir Simulation of Hydraulic Fractures: Performance Improvement Using Pseudo Well Connections

Reservoir simulation is used in most modern reservoir studies to predict future production of oil and gas, and to plan the development of the reservoir. The number of hydraulically fractured wells has risen drastically in recent years due to the increase in production in unconventional reservoirs. Gone are the days of using simple analytic techniques to forecast the production of a hydraulic fracture in a vertical well, and the need to be able to model multiple hydraulic fractures in many stages over long horizontals is now a common practice. The type of simulation approach chosen depends on many factors and is study specific. Pseudo well connection approach was preferred in the current case. Due to the nature of the reservoir simulation problem, a decision needs to be made to determine which hydraulic fracture modeling method might be most suitable for any given study. To do this, a selection of methods is chosen based on what is available at hand, and what is commonly used in various reservoir simulation software packages. The pseudo well connection method, which models hydraulic fractures as uniform conductivity rectangular fractures was utilized for a field of interest referred to as Field A in this paper. Such an assumption of the nature of the hydraulic fracture is common in most modern tools. Field A is a low permeability (0.01md-0.1md), tight (8% to 12% porosity) gas-condensate (API ~51deg and CGR~65 stb/mmscf) reservoir at ~3000m depth. Being structurally complex, it has a large number of erosional features and pinch-outs. The pseudo well connection approach was found to be efficient both terms of replicating data of Field A for a 10 year period while drastically reducing simulation runtime for the subsequent 10 year-period too. It helped the subsurface team to test multiple scenarios in a limited time-frame leading to improved project management.

Impact of Thermal Dissipation on the Lighting Performance and Useful Life of LED Luminaires Applied to Urban Lighting: A Case Study

Currently, LED technology is an established form of lighting in our cities and homes. Its lighting performance, durability, energy efficiency and light, together with the economic savings that its use implies, are displacing other classic forms of lighting. However, some problems associated with the durability of the equipment related to the problems of thermal dissipation and high temperature have begun to be detected, which end up affecting their luminous intensity and the useful life. There are many studies that show a direct relationship between the low quality of LED lighting and the aging of the equipment or its overheating, observing the depreciation of the intensity of the light and the visual chromaticity performance that can affect the health of users by altering circadian rhythms. On the other hand, the shortened useful life of the luminaires due to thermal stress has a direct impact on the LCA (Life Cycle Analysis) and its environmental impact, which indirectly affects human health. The purpose of this article is to compare the results previously obtained, at different contour temperatures, by theoretical thermal simulation of the 3D model of LED street lighting luminaires through the ANSYS Fluent simulation software. Contrasting these results with the practical results obtained with a thermal imaging camera, the study shows how the phenomenon of thermal dissipation plays a fundamental role in the lighting performance of LED technology. The parameter studied in this work is junction temperature (Tj), and how it can be used to predict the luminous properties in the design phase of luminaires in order to increase their useful life.

Riemann Zeta Based Surge Modelling of Continuous Real Functions in Electrical Circuits

Riemann zeta is defined as a function of a complex variable that analytically continues the sum of the Dirichlet series, when the real part is greater than unity. In this paper, the Riemann zeta associated with the finite energy possessed by a 2mm radius, free falling water droplet, crashing into a plane is considered. A modified zeta function is proposed which is incorporated to the spherical coordinates and real analysis has been performed. Through real analytic continuation, the single point of contact of the drop at the instant of touching the plane is analyzed. The zeta function is extracted at the point of destruction of the drop, where it defines a unique real function. A special property is assumed for some continuous functions, where the function’s first derivative and first integral combine together to a nullity at all points. Approximate reverse synthesis of such a function resulted in a special waveform named the dying-surge. Extending the proposed concept to general continuous real functions resulted in the synthesis of the corresponding function’s Dying-surge model. The Riemann zeta function associated with the water droplet can also be modeled as a dying–surge. The Dying- surge model corresponds to an electrical squeezing or compression of a waveform, which was originally defined over infinite arguments, squeezed to a finite number of values for arguments placed very close together with defined final and penultimate values. Synthesized results using simulation software are also presented, along with the analysis. The presence of surges in electrical circuits will correspond to electrical compression of some unknown continuous, real current or voltage function and the method can be used to estimate the original unknown function.

Numerical Simulation of Solids Conveying in Grooved Feed Sections of Single Screw Extruders

For plastic processing extruders with grooved feed sections, the design of the feed section by means of analytical calculation models can be useful to reduce experimental costs. However, these models include assumptions and simplifications that can significantly decrease the prediction accuracy of the throughput due to complex flow behavior. In this paper, the accuracy of analytical modeling for calculating the throughput in a grooved barrel extruder is verified based on a statistical design of experiments. A special focus is placed on the assumptions made in the analytics of a backpressure-independent throughput, the assumption of a block flow and the differentiation of the solids conveying into different conveying cases. Simulative throughput tests with numerical simulation software using the discrete element method, as well as experimental throughput tests, serve as a benchmark. Overall, the analytical modeling already shows a very good calculation accuracy. Nevertheless, there are some outliers that lead to larger deviations in the throughput. The model predominantly overestimates the throughputs, whereby the origin of these deviations is often in the conveying angle calculation. Therefore, a regression-based correction factor for calculating the conveying angle is developed and implemented.

Thermal Behavior of a Light Timber-Frame Wall vs. a Theoretical Simulation with Various Insulation Materials

The objective of this paper is to compare the thermal behavior of a light frame timber wall by measuring 15 test samples with various insulation materials versus a theoretical simulation with the use of a software. This work establishes the variance between the two different methods to measure the thermal transmittance coefficient of timber walls. It is verified that the mean percentage alteration between the two methods is 4.25%. Furthermore, this approach proved that with the use of a simulation software, additional readings (humidity, vapor flux, heat flux, and vapor pressure) can also be considered and measured, enhancing the overall development of a timber wall. This can provide additional information regarding to the characteristics of the masonry’s elements assisting in an improved design of a timber wall with upgraded performance.