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Often in fire resistance testing of packaging vessels and other components, both the heat source temperature and the incident heat flux on a test specimen need to be measured and correlated. Standards such as ASTM E1529 require a specified temperature range from the heat source and a specified heatflux on the surface of the test specimen. There are other standards that have similar requirements. The geometry of the test environment and specimen may make heat flux measurements using traditional instruments (directional flame thermometers (DFTs) and water-cooled radiometers) difficult to implement. Orientation of the test specimen with respect to the thermal environment is also important to ensure that the heat flux on the surface of the test specimen is properly measured. Other important factors in the flux measurement include the thermal mass and surface emissivity of the test specimen. This paper describes the development of a cylindrical calorimeter using water-cooled wide-angle Schmidt-Bolter gauges to measure the incident heat flux for a vessel exposed to a radiant heat source. The calorimeter is designed to be modular to be modular with multiple configurations while meeting emissivity and thermal mass requirements via a variable thermal mass. The results of the incident heat flux and source temperature along with effective/apparent emissivity calculations are discussed.

Several Department of Energy (DOE) facilities have nuclear or hazardous materials stored in robust, welded, stainless-steel containers with undetermined fire-induced pressure response behaviors. Lack of test data related to fire exposure requires conservative safety analysis assumptions for container response at these facilities. This conservatism can in turn result in the implementation of challenging operational restrictions with costly nuclear safety controls. To help address this issue for sites that store DOE 3013 stainless-steel containers, a series of five tests were undertaken at Sandia National Laboratories. The goal of this test series was to obtain the response behavior for various configurations of the DOE 3013 containers when exposed to various fire conditions. Key parameters measured in the test series included identification of failure-specific characteristics such as pressure, temperature, and leak/burst failure type. This paper describes the development and execution of the test series performed to identify these failure-specific characteristics. Work completed to define the test configurations, payload compositions, thermal insults, and experimental setups are discussed. Test results are presented along with corresponding discussions for each test.

Fire suppression systems for transuranic (TRU) waste facilities are designed to minimize radioactive material release to the public and to facility employees in the event of a fire. Currently, facilities with Department of Transportation (DOT) 7A drums filled with TRU waste follow guidelines that assume a fraction of the drums experience lid ejection in case of a fire. This lid loss is assumed to result in significant TRU waste material from the drum experiencing an unconfined burn during the fire, and fire suppression systems are thus designed to respond and mitigate potential radioactive material release. However, recent preliminary tests where the standard lid filters of 7A drums were replaced with a UT-9424S filter suggest that the drums could retain their lid if equipped with this filter. The retention of the drum lid could thus result in a very different airborne release fraction (ARF) of a 7A drum’s contents when exposed to a pool fire than what is assumed in current safety basis documents. This potentially different ARF is currently unknown because, while studies have been performed in the past to quantify ARF for 7A drums in a fire, no comprehensive measurements have been performed for drums equipped with a UT-9424S filter. If the ARF is lower than what is currently assumed, it could change the way TRU waste facilities operate. Sandia National Laboratories has thus developed a set of tests and techniques to help determine an ARF value for 7A drums filled with TRU waste and equipped with a UT-9424S filter when exposed to the hypothetical accident conditions (HAC) of a 30-minute hydrocarbon pool fire. In this multi-phase test series, SNL has accomplished the following: (1) performed a thermogravimetric analysis (TGA) on various combustible materials typically found in 7A drums in order to identify a conservative load for 7A drums in a pool fire; (2) performed a 30-minute pool fire test to (a) determine if lid ejection is possible under extreme conditions despite the UT-9424S filter, and (b) to measure key parameters in order to replicate the fire environment using a radiant heat setup; and (3) designed a radiant heat setup to demonstrate capability of reproducing the fire environment with a system that would facilitate measurements of ARF. This manuscript thus discusses the techniques, approach, and unique capabilities SNL has developed to help determine an ARF value for DOT 7A drums exposed to a 30-minute fully engulfing pool fire while equipped with a UT-9424S filter on the drum lid.

This study experimentally examines the heat flux to objects outside of a firing solid propellant rocket motor plume by measuring the heat flux to gages located at various locations with respect to the rocket nozzle. Because the application of interest may involve multiple motors firing simultaneously, the heat flux from multiple motors is projected based on data collected for a single motor test, and compared to the data from two, three-motor configuration test. Data showing the enhancement from three motors firing can be substantially higher than a single motor firing when the three motors are arranged in a triangular bundle, but this was not found to be the case when the three motors were arranged in a linear bundle (linear to the instrumentation). Based on results of this study, it was concluded that a material of concern which is exposed to as many as 14 motors firing simultaneously, should survive.

Aluminum is commonly used for structural applications in the aerospace industry because of its high strength in relation to its weight. It is necessary to understand the mechanical response of aluminum structures at elevated temperatures such as those experienced in a fire. Additionally, aluminum alloys exhibit many complicated behaviors that require further research and understanding, such as aluminum combustion, oxide skin formation and creep behavior. This paper discusses the effect of grain orientation on aluminum deformation subjected to heating at incipient melt conditions. Experiments were conducted by applying a vertical compressive force to aluminum alloy 7075 block test specimens. Furthermore, compression testing was done on test specimens with the applied load on the long transverse and short transverse orientations. Our results showed that the grain orientation significantly influences aluminum’s strength and mode of failure.

Otothyropsis dialeukos is described from Itá creek, tributary to the upper Río Paraná basin, Paraguay. The new species is distinguished from its congeners by having a unique caudal-fin coloration pattern composed of a brown to almost black background with roundish hyaline blotches in the middle of the outermost branched rays and a hyaline posterior border interrupted in middle rays; abdomen entirely covered by enlarged plates, without naked areas; longer pectoral- and dorsal-fin spines; absence of a raised crest of enlarged odontodes on the posterior portion of the parieto-supraoccipital, and other morphometric and meristic features. Morphological traits and geographic distributions of all species of Otothyropsis and Hisonotus are analyzed and a discussion on the limits between those genera is presented.

Otothyropsis dialeukos, new species Fig. 1; Tables 1, 2 Holotype. MNHNP 3880, female, 34.6 mm SL, Paraguay, Alto Paran��, Hernandarias, Arroyo It�� at Paso It��, near to Embalse de Acaray, ca. 8 km from road between Hernandarias and Ciudad del Este, R��o Paran�� basin, 25��22���56.9���S 54��41���34.8���W, approx. 200 m asl, 21 January 2013, W. Gill Morlis and R. Torres. Paratypes. All from Paraguay, MNHNP 3881, 4, 9.7���34.6 mm SL and MCP 49901, 5 + 1 cs, 9.6���35.8 mm SL, collected with the holotype; and MNHNP 3882, 1, 31.8 mm SL and MCP 49899, 1, 26.3 mm SL, same locality as the holotype, 16 February 2012, W. Gill Morlis and R. Torres. Diagnosis. Otothyropsis dialeukos differs from congeners by its unique caudal-fin coloration pattern, composed of a brown to almost black background with roundish hyaline blotches in the middle of the outermost branched rays and a hyaline posterior border interrupted in middle rays (vs. various color patterns but never two isolated roundish hyalines blotches). The new species is also distinguished from all congeners, except O. marapoama, by having the abdomen entirely covered by enlarged plates (Fig. 2), without naked areas (vs. abdomen almost entirely naked or with naked areas among the plates). The new species further differs from all congeners, except O. piribebuy and O. alicula, by the absence of a raised crest of enlarged odontodes in the posterior portion of the parieto-supraocciptal (vs. presence of such crest). Otothyropsis dialeukos is further distinguished from O. biamnicus, O. polyodon, and O. alicula by having a longer prepelvic length (40.2���44.3%, vs. 36.7���39.3%, 35.8��� 39.5%, and 33.9���37.7% SL, respectively); longer pectoral-fin spine (26.7���30.9%, vs. 18.6���21.3%, 21.4���26.9%, and 16.5���20.0% SL, respectively); longer dorsal-fin spine (23.1���27.1%, vs. 19.4���22.9%, 18.2���22.0% and 19.1��� 22.3% SL, respectively); and shorter caudal peduncle (31.5���34.2%, vs. 41.3���45.1%, 40.0���45.1%, and 39.9���45.4% SL, respectively). The new species differs from O. biamnicus and O. polyodon by having fewer plates in the median lateral series (19���20 vs. 24���25 plates in both species). Otothyropsis dialeukos is distinguished from O. marapoama and O. piribebuy by having more numerous plates between the anal and the caudal fins (11���12 vs. 9��� 10 plates in both). It is further distinguished from O. piribebuy by having a higher number of premaxillary teeth (18���25 vs. 10���19), and by the larger orbital diameter (15.1���18.5, vs. 12.3���15.1% HL), and from O. marapoama, by having a smaller cleithral width (21.5���23.4 vs. 23.8���25.8% SL). Otothyropsis dialeukos can be also distinguished from the species of Hisonotus inhabiting the upper Paran�� River system by the deeper caudal peduncle 9.5���11.0% SL (vs. 7.2���8.5% in H. alberti, 7.9���9.4% in H. depressicauda, 6.6���7.9% in H. depressinotus, 6.9���8.3% in H. francirochai) and S��o Francisco basin (6.8���8.2% in H. vespuccii), or by the plated abdomen (vs. abdomen naked in H. pachysarkos). Description. Morphometrics in Table 1 and meristics in Table 2. Body in dorsal perspective progressively tapering from operculum to end of caudal peduncle. Dorsal profile of head straight to slightly convex from snout tip to middle of parieto-supraoccipital, and straight to slightly concave from that point to dorsal-fin spinelet. Dorsal profile of body sloped and descending from origin of dorsal fin to few plates before end of caudal peduncle. Ventral profile of body relatively straight from head to tail. Greatest body width at cleithrum. Body deepest at dorsal-fin origin and shallowest right before end of caudal-fin peduncle. Trunk and caudal peduncle oval in cross-section and laterally compressed. Adipose fin absent. Head and snout rounded in dorsal view. Snout long with region anterior to nares depressed. Mid-portion of head from end of rostral plates to posterior margin of nares raised. Dorsal margin of orbit slightly elevated. Eye dorsolaterally placed. Iris operculum present. Oral disk round; lower lip relatively short, reaching midway to pectoral girdle. Lips papillose with small fleshy ridge immediately behind dentary. Lower lip with minute papillae except for naked area at median portion of lip just posterior to dentary. Barbel short and laterally positioned, distal portion free from lip margin. Posterior border of lower lip crenulate. Tooth series in premaxilla and dentary forming overall angle of approximately 90 degrees. Teeth bifid, elongated and slender, with large blade-like medial cusp and small lateral cusp. Accessory teeth lacking on premaxilla and dentary in adult and juvenile specimens. Body almost entirely covered by plates, except for ventral surface prior to pectoral girdle, anterior to urogenital opening, around dorsal-fin base, and region from posterior margin of median rostral plate to posterior margin of naris. Abdomen completely covered by enlarged plates (Fig. 2). Four or five large plates in lateral series of abdominal plates (n = 6), wider than long. Plates in median series of abdominal plates comparatively smaller, forming single regular series. Plates in preanal abdominal series large and irregularly distributed, somewhat quadrangular in shape. All abdominal plates bearing small odontodes, except for pair of posterior most preanal abdominal plates which bear larger odontodes on posterior border. Head mostly smooth, lacking odontode crests; odontodes on body uniform in size and distribution, except for augmented odontodes on ventral margin of snout tip. Infraorbital sensory canal entering infraorbital series via compound pterotic. Median series of lateral plates with 19���20 plates, incomplete, ending two plates before the end of the caudal peduncle, but continuously perforated. Mid-dorsal and mid-ventral series of lateral plates with 17 and 16���18 plates, respectively, truncated posteriorly, near to caudal fin. Three irregular transverse rows of predorsal plates, in addition to nuchal plate. Cleithrum and coracoid entirely exposed on ventral surface and covered with odontodes. Arrector fossa open in restricted portion medially, covered by bone shelves from both coracoid and cleithrum laterally. Pectoral fin I,6. Pectoral-fin spine long and somewhat slender. Tip of adpressed pectoral-fin spine almost reaching to end of first pelvic-fin ray; approximately of same width along its length. Odontodes on pectoral-fin spine distributed only on lateral border of spine and slightly increasing in size gradually towards tip. Pectoral-fin branched rays becoming progressively shorter posteriorly. Pectoral-fin axillary slit present in adults and juveniles. Pelvic fin i,5. Pelvic-fin unbranched ray thick and shorter than branched rays. Interradial membrane of pelvic fin fringed distally. Dorsal fin II,7, its origin slightly posterior to vertical through end pelvic-fin base. Dorsal-fin spinelet plate-like, oval to triangular in shape. Anal-fin i,5, its unbranched ray ticker and slightly shorter than remaining branched rays. First unbranched anal-fin ray covered with odontodes; odontodes increasing in size towards ray tip. Caudal-fin I,14,I (1 specimen with I,15,I). Caudal fin weakly forked. Total vertebrae 28 (in 1 cs specimen). Color in alcohol. Ground color of dorsal surface of head dark brown with lighter stripe in front of each nostril. Posterior process of parieto-supraoccipital and dorsal surface of trunk medium brown with dark chromatophores uniformly distributed. Inconspicuous longitudinal dark brown stripe from snout, crossing orbit and opercle, and continuing to end of caudal peduncle. Postrostral plates, opercle, and lateral portion of cleithrum light cream, with many dark chromatophores unevenly sprinkled, forming conspicuous light cream to white cheek. Ventral surface mostly pale yellow, with dark chromatophores unevenly scattered on lower surface of head, lateral portions of abdomen and more heavily concentrated on caudal peduncle. Fin membranes mostly hyaline, with series of small dark dots arranged in irregular transverse bands in all fins except caudal fin. Caudal fin with both rays and membrane mostly dark brown, with roundish hyaline blotches in middle of outermost branched rays, and hyaline posterior border disconnected in middle rays (Fig. 1). Sexual dimorphism. Sexual dimorphism characterized by the possession of a small, conical urogenital papilla immediately posterior to the anal opening in males, which also possess a fleshy flap along the dorsal margin of the first pelvic-fin ray. In addition, males have longer first unbranched pelvic-fin ray (18.8���20.0 vs. 15.2���17.0% SL in females). As usual in Otothyropsis species, males have markedly wider nares than females (13.1���13.3 vs. 7.5���9.4% HL in females), and smaller internareal width (8.1���8.4 vs. 9.2���10.7% HL in females). Distribution. Otothyropsis dialeukos is known only from its type locality, the Arroyo It��, a tributary to the Embalse de Acaray, upper R��o Paran�� basin in Paraguay (Fig. 3). Etymology. From the Greek dialeukos, meaning marked with white, in reference to the white or light cream color of the cheek. A noun in apposition., Published as part of Calegari, B��rbara B., Morlis, Walter Gill & Reis, Roberto E., 2017, A new species of Otothyropsis (Siluriformes: Loricariidae) from the upper R��o Paran�� basin, Paraguay, with a discussion of the limits between Otothyropsis and Hisonotus, pp. 231-245 in Zootaxa 4244 (2) on pages 232-236, DOI: 10.11646/zootaxa.4244.2.5, http://zenodo.org/record/400879

This article examines potential use of a new device called multi-directional heat flux and velocity probe for simultaneous measurement of heat flux and flame speed in a diffusion flame. The probe consists of a thin-wall spherical shell with internal insulation to mitigate internal convection. Both pressure and temperature distributions around the sphere are used to indicate local velocity and heat flux. The multi-directional heat flux and velocity probe appears to be a more promising device than the bidirectional velocity probe in the sense that the sphere is a regular geometry with minimum flow separation and should lead to more predictable behavior. However, an outcome of this study is that the device must be used in conjunction with a fire code computational fluid dynamics model because the boundary layer is not isothermal so that the conventional pressure coefficient for a sphere leads to erroneous results.

It is often necessary to vent an enclosure to allow a controlled depressurization when it is exposed to a decreasing external pressure. This paper derives analytical expressions that can be used to estimate this depressurization. These analytical expressions allow the design of enclosures intended for space launch and other applications. The analytical solutions are compared to numerical solutions and validated by a series of experiments which demonstrate their accuracy.

A virtual thermocouple model for high fidelity multiphysics computer simulation is introduced in this article. Detailed thermocouple and gas temperature (Coherent Anti-Stokes Raman Scattering) measurements were performed using a well-controlled, adiabatic, flat-flame Hencken burner, which provided data for validating the thermocouple model in a Sandia National Laboratories fire code. Comparison of simulation results to test data indicated a mean error of 6% between the thermocouple reading and predicted temperature.

This PIRT exercise identifies a number of factors which can influence thermocouple readings made in fires. Identified factors are: (a) the fuel/oxidizer equivalence ratio and its effect on readings, (b) the influence of the state of oxidation and variation with time for the thermocouple sheath, (c) the convection coefficient models and how experimental readings are influenced by thermocouple diameter and yaw angle, (d) response time of a MIMS thermocouple, and (e) thermocouple end effects.

Particle image velocimetry (PIV) was used to measure velocity fields inside and around oscillating methane-air diffusion flames with a slot fuel orifice. PIV provided velocity and directional information of the flow field comprised of both the flame and air. From this, information on flow paths of entrained air into the flame were obtained and visualized. These show that at low fuel flow rates for which the oscillations were strongest, the responsible mechanism for the oscillating flow appeared to be the repetitive occurrence of flame quenching. PIV findings indicated that quenching appears to be associated primarily with air entrainment. Velocity was found to be considerably larger in regions where quenching occurred. The shedding of vortices in the shear layer occurs immediately outside the boundary of the flame envelope and was speculated to be the primary driving force for air entrainment.

In this study, the development and validation of a non-invasive flame temperature measurement tool from an off-the-shelf ultrasonic rangefinder is discussed. Both `pulse-echo' and single-pass methods are tested. The application of this device to the measurement of bench top flame temperatures is presented.

Strand burner pressure–time data are analyzed to determine if the propellant burning rate can be extracted. This approach is based on strand burner pressure–time history that is related to the temperature change due to exothermic reaction heating of chamber gases and gas addition to the chamber by propellant combustion products. In support of this method, chemical equilibrium calculations were made to project product composition, internal energy, and other needed properties. A mathematical model was formulated and solved numerically and the calculated burning rates were compared with the experimental wire-break time results provided simultaneously and with the propellant manufacturer's results, when available. The comparisons reveal that the approach has merit and that more accurate pressure determination coupled with additional thermochemical information and strand burner gas temperature measurements has the potential to make this approach a viable technique and one that can be applied in conjunction with other burning rate measurements. The proposed method is similar to a well-developed technique which is commonly applied to ballistic powders but with adjustments for the differences in geometry, pressure, and time of event.

This study details the characterization and implementation of a burner designed to simulate solid propellant fires. The burner was designed with the ability to introduce particles (particularly aluminum) into a gas flame. The aluminized flame conditions produced by this burner are characterized based on temperature and heat flux measurements. Using these results, flame conditions are quantified in comparison to other well-characterized reactions including hydrocarbon and propellant fires. The aluminized flame is also used to measure the burning rate of the particles. This work describes the application of this burner for re-creating small-scale propellant flame conditions and as a test platform for experiments that contribute to the development of a particle combustion model, particularly in propellant fires.

Federal regulations require that aircraft cargo compartment smoke detection systems be certified by testing their operation in flight. For safety reasons, only simulated smoke sources are permitted in these certification tests. To provide insight into smoke detection certification in cargo compartments, this research investigates the morphology, transport and optical properties of actual and simulated smoke sources. Experimental data show the morphology of the particulate in smoke from flaming fires is considerably different from simulated smoke. Although the detection of smoldering fires is important as well, only a qualitative assessment and comparison of smoldering sources was possible; therefore, efforts were concentrated on the quantitative comparison of smoke from flaming fires and smoke generators. The particulate for all three different flaming fires was solid with similar morphological properties. Simulated smoke was composed of relatively large liquid droplets, and considerably different size droplets can be produced using a single machine. Transport behavior modeling showed that both the actual and simulated smoke particulates are sufficiently small to follow the overall gas flow. However, actual smoke transport will be buoyancy driven due to the increased temperature, while the simulated smoke temperature is typically low and the release may be momentum driven. The morphology of the actual and simulated smoke were then used to calculate their optical properties. In contrast to the actual smoke from a flaming fire, which is dominated by absorption, all of the extinction for the simulated smoke is due to scattering. This difference could have an impact on detection criteria and hence the alarm time for photoelectic smoke detectors since they alarm based on the scattering properties of the smoke.

Burning aluminized propellants eject reacting molten aluminum drops with a broad size distribution. Prior to this work, in situ measurement of the drop size statistics and other quantitative flow properties was complicated by the narrow depth-of-focus of microscopic videography. Here, digital in-line holography (DIH) is demonstrated for quantitative volumetric imaging of the propellant plume. For the first time, to the best of our knowledge, in-focus features, including burning surfaces, drop morphologies, and reaction zones, are automatically measured through a depth spanning many millimeters. By quantifying all drops within the line of sight, DIH provides an order of magnitude increase in the effective data rate compared to traditional imaging. This enables rapid quantification of the drop size distribution with limited experimental repetition.

The bidirectional velocity probe has been used in various flames to measure local velocity. The device is based on the pressure difference between a closed forward facing cavity and a closed rearward facing cavity. The probes have been noted to indicate a pressure difference greater than that which would be predicted based on Bernoulli's equation. Each device must be experimentally calibrated in a wind tunnel at similar Reynolds number to determine its “amplification factor.” This study uses PIV, flow visualization and CFD to examine the flow field around the probe, as well as an experimental study which compares various probe configurations for measurement of velocity by pressure differential. The conclusion is that the amplification factor is indeed greater than unity but use of the wind tunnel for calibration is questionable.

(1995). Reversing the Demise and Preventing the Apocalypse: Using Alternative Programs to Help African American Males. Middle School Journal: Vol. 27, No. 2, pp. 23-27.

Accidents involving solid propellants containing aluminum can be difficult to model due to the additional heat transfer from molten aluminum or aluminum combustion and impingement/deposition of oxide on target objects. A series of tests has been carried out using a commercially available oxy-acetylene torch and powder feeder to investigate the effects of molten/oxidized aluminum on stainless steel 304 substrates. SEM and EDS have been used to determine diffusion/interaction of aluminum with the stainless steel and characterize the constituents of the resulting interfacial layers. These techniques indicated that at the test conditions, aluminum was undetectably oxidized before it deposited on the substrate surface. However, temperature data from thermocouples attached to backside of each substrate detected an increased heat flux to the substrate when aluminum is introduced into the flame spray. Results also indicate that the boundary layers of the aluminum and stainless steel were well defined implying that little diffusion or solution of the aluminum with the stainless steel occurred.Copyright © 2012 by ASME

A multifunctional reactor is a chemical engineering device that exploits enhanced heat and mass transfer to promote production of a desired chemical, combining more than one unit operation in a single system. The main component of the reactor system under study here is a vertical column containing packing material through which liquid(s) and gas flow cocurrently downward. Under certain conditions, a range of hydrodynamic regimes can be achieved within the column that can either enhance or inhibit a desired chemical reaction. To study such reactors in a controlled laboratory environment, two experimental facilities were constructed at Sandia National Laboratories. One experiment, referred to as the Two-Phase Experiment, operates with two phases (air and water). The second experiment, referred to as the Three-Phase Experiment, operates with three phases (immiscible organic liquid and aqueous liquid, and nitrogen). This report describes the motivation, design, construction, operational hazards, and operation of the both of these experiments. Data and conclusions are included.

The study of aluminum particle ignition in an open atmosphere propellant burn is of particular interest when considering accident scenarios for rockets carrying high-value payloads. This study investigates the temperature of an open atmosphere Atlas V solid propellant burn as a function of height from the burning surface. Two instruments were used to infer this temperature: a two-color pyrometer and a spectrometer. The spectra were fitted to a model of energy states for aluminum monoxide. The temperature which provided the best match between the model and data was taken as the reaction temperature. Emissions above 30 inches from the surface of the propellant were not sufficiently strong for data reduction, perhaps obscured by the alumina smoke cloud. The temperature distribution in the plume increased slightly with distance from the burning surface, presumably indicating the delay in ignition and heat release from the larger aluminum particles in the propellant. The pyrometer and spectrometer results were found to be in excellent agreement indicating plume temperatures in the range of 2300K to 3000K.Copyright © 2011 by ASME

Based on data from large pool fire experiments and computational fire field model simulations, the size, shape, and character of the oxygen-starved interior in large pool fires is estimated. In the interior of the fire and near the pool surface, low average and low mean deviation temperatures were noted in experimental data for low wind conditions. These trends tend to indicate the presence of a non-combusting region. Using average and mean deviation temperature distributions (supplemented by heat flux measurements) from several data sets, the spatial extent of the vapor dome is estimated for a range of wind conditions. These estimates are compared with fire field model results of temperature and fuel/air concentration distributions. Predicted and measured temperature trends, supported by heat flux data, illustrate the importance of object placement within the fire during system fire survivability testing. The presence of this region also supplements conventional pool fire representations which are based on a continuous flame zone which extends to the pool surface.

The bidirectional probe has been used in combustion environments to measure localized flame velocities. The device measures the pressure difference between a closed forward-facing cavity, and a closed rearward-facing cavity. Each device must be experimentally calibrated to determine the “amplification factor,” which is unity if the measured differential pressures match Bernoulli’s equation. It is hypothesized that the probe design disrupts the flow, creating turbulence and irreversibilities, resulting in measured pressure differences. This study uses computational fluid dynamics, particle image velocimetry, and flow visualization techniques to examine the flow field around the probe, as well as an experimental study exploring the impact of minor changes in probe design on differential pressure measurements for velocity calculations.Copyright © 2009 by ASME

Some thermocouple experiments were carried out in order to obtain sensitivity of thermocouple readings to fluctuations in flames and to determine if the average thermocouple reading was representative of the local volume temperature for fluctuating flames. The thermocouples considered were an exposed junction thermocouple and a fully sheathed thermocouple with comparable time constants. Either the voltage signal or indicated temperature for each test was recorded at sampling rates between 300-4,096 Hz. The trace was then plotted with respect to time or sample number so that time variation in voltage or temperature could be visualized and the average indicated temperature could be determined. For experiments where high sampling rates were used, the signal was analyzed using Fast Fourier Transforms (FFT) to determine the frequencies present in the thermocouple signal. This provided a basic observable as to whether or not the probe was able to follow flame oscillations. To enhance oscillations, for some experiments, the flame was forced. An analysis based on thermocouple time constant, coupled with the transfer function for a sinusoidal input was tested against the experimental results.

Detailed herein are the results of a validation comparison. The experiment involved a 2 meter diameter liquid pool of Jet-A fuel in a 13 m/s crosswind. The scenario included a large cylindrical blocking object just down-stream of the fire. It also included seven smaller calorimeters and extensive instrumentation. The experiments were simulated with Fuego. The model included several conduction regions to model the response of the calorimeters, the floor, and the large cylindrical blocking object. A blind comparison was used to compare the simulation predictions with the experimental data. The more upstream data compared very well with the simulation predictions. The more downstream data did not compare very well with the simulation predictions. Further investigation suggests that features omitted from the original model contributed to the discrepancies. Observations are made with respect to the scenario that are aimed at helping an analyst approach a comparable problem in a way that may help improve the potential for quantitative accuracy.

A liquid pool fire evaporates the liquid fuel at a rate that is governed by heat and mass transport. Predictive evolution of vaporized fuel from a pool can be obtained only by applying the correct boundary conditions and modeling the significant physics of the pool. However, pool fires can occur in a variety of configurations, and the significant physics of a fire change depending on the environment of the fire. Sandia National Laboratories has invested in fire experiments and modeling for a wide variety of scales and configurations over the last 40 years, and an accumulation of this knowledge can be applied to assessing the relative importance of various phenomena. This paper consolidates existing knowledge in the context of phenomena identification and ranking in order to guide future efforts aimed at improving the quantitative predictive capabilities of liquid fuel pool models. Ultimately, the intent is to converge to a predictive model of a liquid pool fire that can be implemented in a CFD model and confidently applied to risk assessment studies.Copyright © 2006 by ASME

A joint experimental and computational study was performed to evaluate the capability of the Sandia Fire Code VULCAN to predict thermocouple response temperature. Thermocouple temperatures recorded by an Inconel-sheathed thermocouple inserted into a near-adiabatic flat flame were predicted by companion VULCAN simulations. The predicted thermocouple temperatures were within 6% of the measured values, with the error primarily attributable to uncertainty in Inconel 600 emissivity and axial conduction losses along the length of the thermocouple assembly. Hence, it is recommended that future thermocouple models (for Inconel-sheathed designs) include a correction for axial conduction. Given the remarkable agreement between experiment and simulation, it is recommended that the analysis be repeated for thermocouples in flames with pollutants such as soot.

A series of experiments was performed to better characterize the boundary conditions from an inconel heat source ('shroud') painted with Pyromark black paint. Quantifying uncertainties in this type of experimental setup is crucial to providing information for comparisons with code predictions. The characterization of this boundary condition has applications in many scenarios related to fire simulation experiments performed at Sandia National Laboratories Radiant Heat Facility (RHF). Four phases of experiments were performed. Phase 1 results showed that a nominal 1000 C shroud temperature is repeatable to about 2 C. Repeatability of temperatures at individual points on the shroud show that temperatures do not vary more than 10 C from experiment to experiment. This variation results in a 6% difference in heat flux to a target 4 inches away. IR camera images showed the shroud was not at a uniform temperature, although the control temperature was constant to about {+-}2 C during a test. These images showed that a circular shaped, flat shroud with its edges supported by an insulated plate has a temperature distribution with higher temperatures at the edges and lower temperatures in the center. Differences between the center and edge temperatures were up to 75 C. Phase 3more » results showed that thermocouple (TC) bias errors are affected by coupling with the surrounding environment. The magnitude of TC error depends on the environment facing the TC. Phase 4 results were used to estimate correction factors for specific applications (40 and 63-mil diameter, ungrounded junction, mineral insulated, metal-sheathed TCs facing a cold surface). Correction factors of about 3.0-4.5% are recommended for 40 mil diameter TCs and 5.5-7.0% for 63 mil diameter TCs. When mounted on the cold side of the shroud, TCs read lower than the 'true' shroud temperature, and the TC reads high when on the hot side. An alternate method uses the average of a cold side and hot side TC of the same size to estimate the true shroud temperature. Phase 2 results compared IR camera measurements with TC measurements and measured values of Pyromark emissivity. Agreement was within measured uncertainties of the Pyromark paint emissivity and IR camera temperatures.« less

Fire modeling software has become increasingly important for the prediction of fire development in industrial and transportation accident scenarios. A key parameter required as input to fire models is the rate at which the fuel load is consumed, often reported as the fuel regression rate. This variable is linked to the energy output of the fire in a tightly coupled, cyclical fashion [1] and, for the most part, must be determined experimentally for model verification. Measurement of fuel regression rate proves to be difficult and is further complicated by the fact that ambient winds are typically significant in large accident scenarios. Wind is known to greatly affect fire behavior [2,3].Copyright © 2004 by ASME

Heat flux is an important parameter for characterization of the thermal impact of a fire on its surroundings. However, heat flux cannot be measured directly because it represents the rate of heat transfer to a unit area of surface. Therefore, most heat flux measurements are based on the measurement of temperature changes at or near the surface of interest [1,2]. Some instruments, such as the Gardon gauge [3] and the thermopile [2], measure the temperature difference between a surface and a heat sink. In radiation-dominated environments, this difference in temperature is often assumed to be linearly related to the incident heat flux. Other sensors measure a surface and/or interior temperature and inverse heat conduction methods frequently must be employed to calculate the corresponding heat flux [1,4]. Typical assumptions include one-dimensional conduction heat transfer and negligible heat loss from the surface. The thermal properties of the gauge materials must be known and, since these properties are functions of temperature, the problem often becomes non-linear.Copyright © 2004 by ASME

The primary objective of the Safety and Survivability of Aircraft Initiative is to improve the safety and survivability of systems by using validated computational models to predict the hazard posed by a fire. To meet this need, computational model predictions and experimental data have been obtained to provide insight into the thermal environment inside an aircraft dry bay. The calculations were performed using the Vulcan fire code, and the experiments were completed using a specially designed full-scale fixture. The focus of this report is to present comparisons of the Vulcan results with experimental data for a selected test scenario and to assess the capability of the Vulcan fire field model to accurately predict dry bay fire scenarios. Also included is an assessment of the sensitivity of the fire model predictions to boundary condition distribution and grid resolution. To facilitate the comparison with experimental results, a brief description of the dry bay fire test fixture and a detailed specification of the geometry and boundary conditions are included. Overall, the Vulcan fire field model has shown the capability to predict the thermal hazard posed by a sustained pool fire within a dry bay compartment of an aircraft; although, more extensive experimental data and rigorous comparison are required for model validation.

Macroscopic fire parameters such as fuel regression rate, flame height and flame tilt are critical to the development of detailed fire models and empirical tools for hazard analysis [1–3]. As a result, these characteristics have been investigated by many researchers using various measurement methods in studies of liquid fuelled pool fires of different diameters and fuel types, under a range of crosswind conditions. In investigations related to transportation accidents, fire scenarios have been complicated further through interactions between the fire and upwind or downwind objects [1,2]. Of particular interest is the determination of fuel regression rate, an important parameter but one that is generally difficult to characterize accurately. Many techniques have been reported for measurement of fuel regression rate. These include load cells [2,4,5], differential pressure systems [2,5–7], sight glass and float-type level meters [6–8] and thermocouple rakes [1]. In general, load cells have been employed most successfully for measurements in smaller scale fires [2,4], while researchers have turned to differential pressure and thermocouple type systems for measurements in fires above 5 m diameter [2,6,7]. All the techniques have been used with varying levels of success to measure fuel regression rate under quiescent conditions. Under crosswind conditions and in cases with an object present, however, inherent wandering of the fire plume and dynamic wind loading on the pool can be of additional concern as they affect the accuracy and repeatability of the measurements [1,2,6,7]. In several excellent reviews, available results have been summarized and used to derive empirical correlations relating overall fire characteristics to fire diameter, fuel type and/or wind velocity [3,9–11].Copyright © 2003 by ASME

Solid rocket propellant plume temperatures have been measured using spectroscopic methods as part of an ongoing effort to specify the thermal-chemical-physical environment in and around a burning fragment of an exploded solid rocket at atmospheric pressures. Such specification is needed for launch safety studies where hazardous payloads become involved with large fragments of burning propellant. The propellant burns in an off-design condition producing a hot gas flame loaded with burning metal droplets. Each component of the flame (soot, droplets and gas) has a characteristic temperature, and it is only through the use of spectroscopy that their temperature can be independently identified.