An international study of fire modelling was conducted prior to the Dalmarnock Fire Test One in order to assess the state-of-the-art of fire simulations using a round-robin approach. This test forms part of the Dalmarnock Fire Tests, a series of experiments conducted in 2006 in a high-rise building. The philosophy behind the tests was to provide measurements in a realistic fire scenario involving multiple fuel packages and non-trivial fire growth, and with an instrumentation density suitable for comparison with computational fluid dynamics models. Each of the seven round-robin teams independently simulated the test scenario a priori using a common detailed description of the compartment geometry, fuel packages, ignition source and ventilation conditions. The aim of the exercise was to forecast the fire development as accurately as possible and compare the results. The aim was not to provide an engineering analysis with conservative assumptions or safety factors. Comparison of the modelling results shows a large scatter and considerable disparity among the predictions, and between predictions and experimental measurements. The scatter of the simulations is much larger than the error and variability expected in the experiments. The study emphasises on the inherent difficulty of modelling fire dynamics in complex fire scenarios like Dalmarnock, and shows that the accuracy to predict fire growth (i.e. evolution of the heat released rate) is, in general, poor.

SUMMARY One of the major challenges of shape optimisation in practical industrial cases is to generically parametrise the wide range of complex shapes. A novel approach is presented, which takes CAD descriptions as input and produces the optimal shape in CAD form using the control points of the Non‐Uniform Rational B‐Splines (NURBS) boundary representation as design variables. An implementation of the NURBS equations in source allows to include the CAD‐based shape deformation inside the design loop and evaluate its sensitivities efficiently and robustly. In order to maintain or establish the required level of geometric continuity across patch interfaces, geometric constraints are imposed on the control point displacements. The paper discusses the discrete adjoint flow solver used and the computation of the complete sensitivities of the design loop by differentiating all components using automatic differentiation tools. The resulting rich but smooth deformation space is demonstrated on the optimisation of a vehicle climate duct. Copyright © 2013 John Wiley & Sons, Ltd.

Fire detection and monitoring sensors, fire modelling, fire fighting and command and control are usually perceived as independent issues within fire safety. Sensor data is associated to detection and alarm and to some minor extent as a source of very basic information for building management or emergency response. The streams of data emerging from sensors are deemed to lead to a rapid information overload, so the pervasive sensor deployment (now common in modern buildings) is entirely independent of procedures associated to emergency management. Fire modelling follows a similar path because model output is not robust enough, not fast enough and the information generated by such simulations rapidly escalates in quantity and complexity so that no commander can assimilate it. Fire fighting is therefore left as an isolated activity that does not benefit much from sensor data or the potential of modelling the event. This separation is naturally induced by the complexity of a fire event and represents the biggest barrier to the useful development of sensor technology and fire modelling into emergency response. Therefore, current technology applied to fire is decades behind sensor development for other related areas like military operations or intruder security. There is no apparent use for more complex and expensive sensors. This paper describes the different processes that need to be studied to establish a path by which a collection of sensor data can be used to provide early detection, robust building management and adequate information to assist fire fighting operations.

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The sensitivity of computer fire modelling using results from NIST's Fire Dynamics Simulator (FDS) to a set of input parameters related to fire growth has been analyzed. The scenario simulated is the real-scale Dalmarnock Fire Test One and the modelling results are compared to the measurements. Fire size and location, convection, radiation and combustion parameters were varied in order to determine the associated degree of sensitivity. Emphasis is put in the prediction of secondary ignition and time to flashover. In this context and while keeping the HRR constant, simulations of fire growth are significantly sensitive to location of the heat release rate (HRR), fire area, flame radiative fraction, and material thermal and ignition properties. The simulations are relatively insensitive to the heat of combustion (while keeping the HRR constant), the soot yield and the heating from the smoke layer. The results indicate that the future development of successful fire forecast methodologies of fire growth using CFD must focus on the global HRR as well as the important parameters identified here. KEYWORDS: FDS, prediction, Dalmarnock, modelling, forecast NOMENCLATURE LISTINGHeat of combustion (kJ/kg)