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Graphical summaries are becoming important tools for evaluating designs. The need to compare designs in term of their prediction variance properties advanced this development. A recent graphical tool, the Fraction of Design Space plot, is useful to calculate the fraction of the design space where the scaled prediction variance (SPV) is less than or equal to a given value. In this dissertation we adapt FDS plots, to study three specific design problems: robustness to model assumptions, robustness to measurement error and design properties for generalized linear models (GLM). This dissertation presents a graphical method for examining design robustness related to the SPV values using FDS plots by comparing designs across a number of potential models in a pre-specified model space. Scaling the FDS curves by the G-optimal bounds of each model helps compare designs on the same model scale. FDS plots are also adapted for comparing designs under the GLM framework. Since parameter estimates need to be specified, robustness to parameter misspecification is incorporated into the plots. Binomial and Poisson examples are used to study several scenarios. The third section involves a special type of response surface designs, mixture experiments, and deals with adapting FDS plots for two types of measurement error which can appear due to inaccurate measurements of the individual mixture component amounts. The last part of the dissertation covers mixture experiments for the GLM case and examines prediction properties of mixture designs using the adapted FDS plots. / Ph. D.

The exposure from a localized vehicle fire has been observed to produce excessive damage onto highway bridge structural elements including complete collapse of the infrastructure. The occurrence of a fire beneath a bridge can lead to significant economic expense and loss of service even if the bridge does not collapse. The focus of the current research is to assess and evaluate the effect of realistic localized fire exposures from vehicles on the bridge structural integrity and to guide future development of highway bridge design with improved fire resistance. In this research, the bridge structural element response was predicted through a series of three loosely coupled analyses: fire analysis, thermal analysis, and structural analysis. Two different types of fire modeling methodologies were developed in this research and used to predict the thermo-structural response of bridge structural elements: one to model the non-uniform exposure due to a vehicle fire and another to predict response due to a standard uniform furnace exposure. The vehicle fire scenarios required coupling the computational fluid dynamics (CFD) code Fire Dynamics Simulator (FDS) with Abaqus while the furnace exposure scenarios were all done within Abaqus. Both methodologies were benchmarked against experimental data. Using the developed methodologies, simulations were initially performed to predict the thermo-structural response of a single steel girder-concrete deck composite assembly to different local, non-uniform fires and uniform standard furnace fire exposures. The steel girder-concrete deck composite assembly was selected since it is a common bridge design. Following this, a series of simulations were performed on unprotected highway bridges with multiple steel plate girders and steel tub girders subjected to localized fires. The analyses were used to evaluate the influence of a fire scenario on the bridge element response, identify the factors governing the failure of bridge structural elements subjected to a localized fire exposure, and provide guidance in the design of highway bridge structural elements against fire hazards. This study demonstrates that girder geometry affected both the dynamics of the fire as well as the heat transfer to the bridge structural elements which resulted in a different structural response for the bridge. A heavy goods vehicle (heat release rate of 200 MW) and tanker fires (heat release rate of 300 MW) were predicted to cause the bridge to fail due to collapse, while smaller fires did not. The geometric features of the plate girders caused the girder elements to be exposed to higher heat fluxes from both sides of the girder resulting in collapse when exposed to a HGV fire. Conversely, the closed feature of the box girder does not allow the interior surfaces to be in direct contact with the flames and are only exposed to the internal reradiation from surfaces inside the girder. As a result, the single and double lane tub girder highway bridge structure does not fail due to a heavy goods vehicle fire exposure. / Ph. D.

Die Digitalisierung im Bauwesen schreitet immer weiter voran und während in diesem Zusammenhang oftmals das Stichwort Building Information Modeling (BIM) fällt, entwickeln sich Disziplinen wie das Brandschutzingenieurwesen (BSI) unabhängig weiter. Das Brandschutzbüro Brandschutz Consult Ingenieurgesellschaft mbH Leipzig (BCL) verwendet das BSI, um ingenieurtechnische Verfahren heranzuziehen. BCL verfolgt als Unternehmensphilosophie das Ziel, mit neuen Methoden und Erkenntnissen ständig die eigenen Prozesse zu optimieren und zu erweitern. Unter diesem Gesichtspunkt soll in dieser Arbeit in Kooperation mit BCL untersucht werden, inwieweit sich die Ergebnisse aus einer Brandsimulation, darunter besonders der Rauch, in einer virtuellen Realität (engl. Virtual Reality (VR)) darstellen und in bestehende oder potenzielle Anwendungsfälle integrieren lassen. Dazu soll zunächst mit einer Betrachtung der brandschutztechnischen Grundlagen inklusive des BSIs und einer Analyse zum Stand des Brandschutzes in BIM begonnen werden. Im nächsten Schritt sind für die Brandsimulation bestimmte Fragen zu klären, wie z.B. eine entsprechende Berechnung technisch abläuft und welche Ausgabedaten und -formate eine solche Simulation bereitstellt. Zur Darstellung der Simulationsergebnisse in virtuellen Realitäten werden Grafik.Engines benötigt, die VR-Anwendungen ermöglichen. Wichtige Untersuchungsgegenstände sind z.B. die anwendbaren Programmier- und Skriptsprachen, mit deren Einsatz die Daten eingelesen und visualisiert werden können. Für die gefundenen Grafik-Engines wird dann recherchiert, ob es bereits bestehende Anwendungen oder Prozesse zur Darstellung von Brandsimulationen gibt. Ist dies der Fall, sollen deren Workflows untersucht werden, um anschließend ihre grundsätzliche Einsatzfähigkeit zu bewerten und Verbesserungsvorschläge zu äußern...:1. Prozesse im Brandschutz 1.1. Brandschutztechnische Grundlagen 1.2. Angewandte Ingenieurmethoden 1.3. Brandschutz mit Building Information Modeling 2. Ablauf einer Brandsimulation 2.1. Verfügbare Software 2.2. Aufbau einer FDS-Eingabedatei 2.3. Generieren von Simulationsdaten in FDS 2.4. Ausgabedaten und -formate 3. Software zur Darstellung in VR 3.1. Blender 3.2. Unity Engine 3.3. Unreal Engine 3.4. Vergleich der Engines 4. Visualisierung der Brandsimulation 4.1. Konzept der Datenübertragung 4.2. Bestehende Workflows für VR-Programme 4.3. Versuchsdurchführung 4.4. Auswertung der Versuche 5. Anwendungsfälle und Optimierungspotenzial 5.1. Potenzielle Einsatzmöglichkeiten 5.2. Optimierungspotenzial 6. Fazit A. Beispielmodell Blender B. Beispielmodell VRSmokeVis C. Prüfmodell Abkürzungsverzeichnis Abbildungsverzeichnis Tabellenverzeichnis Literaturverzeichnis / Digitization in the construction industry is progressing and while the keyword Building Information Modeling (BIM) is frequently mentioned, disciplines like the fire safety engineering are also evolving independently. The fire protection office Brandschutz Consult Ingenieurgesellschaft mbH Leipzig (BCL)) uses fire safety engineering for including engineering procedures. As a corporate philosophy BCL pursues the goal of constantly optimizing and expanding its own processes with new methods and scientific findings. From this point of view, in cooperation with BCL, this master thesis will examine to which extent it is possible to visualize the results of a fire simulation, in particular including the smoke, in Virtual Reality (VR) and to integrate them into existing or evolving applications. For this purpose, a consideration of the fire protection basics including fire protection engineering and an analysis of the status of fire protection in BIM has been started. In the next step the fire simulation must be investigated, i.e. how the corresponding calculation technically works and which output data and formats such a simulation provides. Graphic engines that enable VR applications are required to display the simulation results in VR. Important objects of investigation are e.g. the applicable programming and scripting languages. Those scripting languages are used to import and visualize the data. For the graphic engines found, research is initiated to determine whether there are already existing applications or processes for displaying fire simulations. If this is the case these workflows should be examined in order to subsequently evaluate their fundamental usability and to express suggestions for improvement. If possible, some of the optimizations should be carried out. Based on the existing processes in fire protection helpful application options are derived, for which the use must be proven in future projects.:1. Prozesse im Brandschutz 1.1. Brandschutztechnische Grundlagen 1.2. Angewandte Ingenieurmethoden 1.3. Brandschutz mit Building Information Modeling 2. Ablauf einer Brandsimulation 2.1. Verfügbare Software 2.2. Aufbau einer FDS-Eingabedatei 2.3. Generieren von Simulationsdaten in FDS 2.4. Ausgabedaten und -formate 3. Software zur Darstellung in VR 3.1. Blender 3.2. Unity Engine 3.3. Unreal Engine 3.4. Vergleich der Engines 4. Visualisierung der Brandsimulation 4.1. Konzept der Datenübertragung 4.2. Bestehende Workflows für VR-Programme 4.3. Versuchsdurchführung 4.4. Auswertung der Versuche 5. Anwendungsfälle und Optimierungspotenzial 5.1. Potenzielle Einsatzmöglichkeiten 5.2. Optimierungspotenzial 6. Fazit A. Beispielmodell Blender B. Beispielmodell VRSmokeVis C. Prüfmodell Abkürzungsverzeichnis Abbildungsverzeichnis Tabellenverzeichnis Literaturverzeichnis

"The construction of smoke hazard management systems in large buildings such as shopping malls, cinemas, airports and train stations are increasingly being based on performance based design. Hot smoke tests are a method of using simulated fire conditions to evaluate the functionality of the completed building and the installed systems without causing damage. The author amongst others performed hot smoke tests (HST) according to Australian Standard AS 4391 -1999 in several buildings. In some tests air temperatures, air speed and smoke optical density were recorded at several locations during the test of which two tests are reported. These were later modelled by the author using Fire Dynamic Simulator (FDS) to show that typical fire protection engineering consultant applying the computer model may reasonably predict some results comparable to a full sized simulation scenario. However, some aspects were not well predicted. The modelling was improved by the outcomes of an investigation of the relationship between fuel properties, plume temperature and dynamics, and grid sensitivity. Areas of potential further improvement were identified. This work highlighted that the conditions witnessed in a hot smoke test can provide a guide, but do not represent all aspects of a real fire or design fire scenario. Although the FDS hot smoke model predicted comparable results to the hot smoke test, whilst suitable for system design, computer modelling should never be used as a system installation certification tool. Data from hot smoke tests, if gathered cost effectively, can be a valuable resource for computer model verification."

"Fire tests involving heavy goods vehicles (HGVs) in a road tunnel with forced ventilation in Norway, conducted by SP, demonstrated a pulsation phenomena that is similar to oscillating flames and thermo-acoustic instabilities previously observed in vitiated compartments and resonant systems that meet the Rayleigh criterion, respectively. This current study investigates whether the causal phenomena can be determined using either a simple, one-dimensional fluid dynamics model or a computation fluid dynamics program. It is assumed that the leading cause for pulsation is a locally under-ventilated fire. Theoretical analysis shows that this assumption is valid and how such conditions can cause the flow field to change. A simple model is developed for a tunnel fire with forced, longitudinal ventilation. The results qualitatively represent the test data and support the assumption of a locally vitiated fire. A more sophisticated analysis, involving the Fire Dynamics Simulator (FDS) Version 4.0, provides similar results. Although FDS calibration, using similar experiment data from the Memorial Tunnel Ventilation Test Program, demonstrates model limitations in predicting smoke layers near the solid boundaries under forced flow field, the qualitative results from both models indicates that pulsation in large tunnel fires under forced ventilation conditions results from poor mixing of the bulk flow in the near field of the fire."

A series of numerical modeling studies were conducted to characterize the mass flow rates in balcony spill plumes (BSP), a type of buoyant fire plume occurring in atria. The variation of BSP mass flow rate as a function of elevation, fire size and fire compartment geometry was examined both numerically and experimentally. A new method for estimation of BSP mass flow rates, appropriate for design of smoke management systems in high-elevation atria, was developed based on simulations of BSP mass flow rate. An experimental program conducted in a 12 m high atrium measured BSP mass flow rates as well as temperatures in the fire compartment and atrium. This data was used to evaluate CFD models of the fire compartment and atrium in the experimental facility. These were implemented using the Fire Dynamics Simulator (FDS) software. The models were extended to investigate BSP behaviour at elevations up to 50 m. The removal of atrium walls in the model to allow free development of the BSP is a unique approach among published numerical modeling studies of BSP behaviour. The high-elevation CFD model was used to perform a parametric study of BSP mass flow rate as a function of elevation, fire size and fire compartment geometry. Predictions of BSP mass flow rate from this study extend to 50 m above the atrium floor, extending the range of elevations represented in the published experimental data (<= 9 m). Data from the parametric study was used to develop a new method for estimation of BSP mass flow rates at high elevations. BSP mass flow rates estimated using the new method are shown to be bounded by values estimated using existing methods based on low-elevation experimental data.

A series of numerical modeling studies were conducted to characterize the mass flow rates in balcony spill plumes (BSP), a type of buoyant fire plume occurring in atria. The variation of BSP mass flow rate as a function of elevation, fire size and fire compartment geometry was examined both numerically and experimentally. A new method for estimation of BSP mass flow rates, appropriate for design of smoke management systems in high-elevation atria, was developed based on simulations of BSP mass flow rate. An experimental program conducted in a 12 m high atrium measured BSP mass flow rates as well as temperatures in the fire compartment and atrium. This data was used to evaluate CFD models of the fire compartment and atrium in the experimental facility. These were implemented using the Fire Dynamics Simulator (FDS) software. The models were extended to investigate BSP behaviour at elevations up to 50 m. The removal of atrium walls in the model to allow free development of the BSP is a unique approach among published numerical modeling studies of BSP behaviour. The high-elevation CFD model was used to perform a parametric study of BSP mass flow rate as a function of elevation, fire size and fire compartment geometry. Predictions of BSP mass flow rate from this study extend to 50 m above the atrium floor, extending the range of elevations represented in the published experimental data (<= 9 m). Data from the parametric study was used to develop a new method for estimation of BSP mass flow rates at high elevations. BSP mass flow rates estimated using the new method are shown to be bounded by values estimated using existing methods based on low-elevation experimental data.

The fire development and flame spread in the railway carriages are investigated by performing a set of simulations using a widely accepted simulation software called &amp / #8216 / Fire Dynamics Simulator&amp / #8217 / . Two different rolling stock models / representing a train made up of physically separated carriages, and a 4-car train with open wide gangways / have been built to examine the effects of train geometry on fire development and smoke spread within the trains. The simulations incorporate two different ignition sources / a small size arson fire, and a severe baggage fire incident. The simulations have been performed incorporating variations of parameters including tunnel geometry, ventilation and evacuation strategies, and combustible material properties. The predictions of flame spread within the rolling stock and values of the peak heat release rates are reported for the simulated incident cases. In addition, for a set of base cases the onboard conditions are discussed and compared against the tenability criteria given by the international standards. The predictions of heat release rate and the onboard conditions from the Fire Dynamics Simulator case studies have been checked against the empirical methods such as Duggan&amp / #8217 / s method and other simulation softwares such as CFAST program.

Fire is a complex phenomenon including many parameters. The nature of fire makes it a very dangerous and hazardous. For many reasons the number of tunnels are increasing on earth and fire safety is one of the major problem related to tunnels. This makes important to predict and understand the behavior of fire, i.e., heat release rate, smoke movement, ventilation effect etc. The literature includes many experimental and numerical analyses for different conditions for tunnel fires. This study investigates pool fire of three different fuel sources: ethanol, gasoline and their mixture for different ventilation conditions, different geometries and different amounts. Combustion gases and the burning rates of the fuel sources are measured and analyzed. The numerical simulation of the cases is done with Fire Dynamics Simulator (FDS), a CFD code developed by NIST.