Risk-based spacecraft fire safety experiments

Apostolakis, G.; Catton, I.; Issacci, F.; Jones, Sharon M.; Paul, Mark; Paulos, Todd; Paxton, K.

doi:10.1016/0951-8320(95)00046-5

Cited by 14 publications

(9 citation statements)

References 14 publications

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“…In this report a series of currents were loaded to the wires to find out the ignition point. Apostolakis et al [18] loaded three levels of power (100 W, 600 W, 1200 W) to wires to study the smoke particles of the insulation. Fujita et al [19] also studied the effect of gravity on the ignition of electrical wire with short-term excess electric current and found out it was easier to obtain in microgravity than under normal gravity.…”

Section: Introductionmentioning

confidence: 99%

Ignition and Flame Propagation of Externally Heated Electrical Wires with Electric Currents

Wang

Zhao

et al. 2015

Fire Technol

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This paper describes the results of an experimental and numerical study of the effect of electric current on the ignition and flame propagation propensity of polyethylene-insulated copper conductor electrical wire. Two simplified models were developed to describe the ignition and steady flame propagation of energized electrical wires exposed to an external heat flux, respectively. The models predict that for a higher-conductance wire it is more difficult to achieve ignition and flame propagation. Experiments were performed on three types of electrical wires with different conductor diameter of 0.5 mm, 0.8 mm and 1.1 mm and the same insulation thickness of 0.15 mm. A 20 mm long coil heater was used as the ignition source to generate a controlled heat flux. Experiments show that increasing the current of wire leads to a convexly decreasing critical heat flux for ignition, agreeing with model predictions. Effects of different currents on insulation temperature and flame height are discussed. The flame width of three types of wires could be considered invariable with the current, which are 9.06 mm, 12.45 mm and 15.07 mm respectively. The heat release rate of flame is discussed through the volume of flame and a correlation is presented that DV F µ I 2 . The likelihood for molten PE dripping is determined by the absolute and relative fuel load for different wires. Finally, the correlation between the flame propagation velocity and the current of wire, Dv f µ I 2 , is demonstrated.

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Section: Introductionmentioning

confidence: 99%

Ignition and Flame Propagation of Externally Heated Electrical Wires with Electric Currents

Wang

Zhao

et al. 2015

Fire Technol

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“…2,3 The fire suppression mechanism would include identification of critical locations of fire risk, frequency of occurrence, fire growth time, estimation of detection and corresponding agent delivery time and how the system deals with the event upon completing the suppression process. 1 The representation of design fire is carried out in modelling four phases of fire -(a) linear in time in the incipient stage, (b) time squared in the growth stage, (c) steady with time in the full fire development phase and (d) exponential growth in the decay phase. A risk model was developed which studied the effects of fire suppression for passenger ships.…”

Section: Introductionmentioning

confidence: 99%

Nitrogen as an environmentally friendly suppression agent for aircraft cargo fire safety

Diakostefanis

Sampath

Dinesh

et al. 2021

Journal of Fire Sciences

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Fire suppression systems in cargo compartments are a certification requirement for commercial aircraft safety. Halon production was banned and usage ends in 2040 according to Montreal Protocol for environmental reasons. This necessitates an alternative environmentally friendly agent. Quantitative analysis of nitrogen as agent established suitability of the suppression system. The Minimum Performance Standards specifies the qualification procedure of an agent through four scenarios – bulk load; containerised load; surface burning; and aerosol can explosion. Empirical sources from Airbus, independent computational fluid dynamics studies and small-scale cup-burner tests indicate suitability of nitrogen specific to aircraft cargo fire suppression. The nitrogen delivery system and the experimental apparatus are presented. Extensive commissioning tests verified instrumentation reliability. All the four scenarios were conducted at Cranfield University, in a replica of a wide-body aircraft cargo compartment. In a reduced oxygen environment (11%) obtained with nitrogen discharge, the aerosol can explosion tests were performed without any evidence of explosion or pressure increase beyond the expected baseline value. The surface burning scenario was completed successfully and passed the Minimum Performance Standard criteria. The maximum average temperature was found to be 220°C (limit – 293°C). All the scenarios passed the Minimum Performance Standard criteria for indicating successful prevention of Class B fire re-ignition. Similarly, the containerised and bulk-load scenarios obtained results that passed the Minimum Performance Standard criteria for successfully maintaining continued fire suppression for a specified period of time. The maximum average temperature in containerised-load fire scenario was found to be 210°C (limit – 343°C) and in bulk-load scenario was 255°C (limit – 377°C). Additional qualification criteria and system design are presented in this article according to the Minimum Performance Standard format. This work can be extended to introduce standard testing for safety critical systems, such as engine bay and lithium-ion fires.

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“…( 11 ) They have also been used to identify research needs. ( 12 ) Reference 2 recommends that this approach be used for terrorist threats and that it serve as the basis for risk management. This methodology is known as probabilistic risk assessment (PRA), quantitative risk assessment (QRA), ( 13 ) or performance assessment.…”

Section: Introductionmentioning

confidence: 99%

A Screening Methodology for the Identification and Ranking of Infrastructure Vulnerabilities Due to Terrorism

Apostolakis¹,

Lemon²

2005

Risk Analysis

228

108

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The extreme importance of critical infrastructures to modern society is widely recognized. These infrastructures are complex and interdependent. Protecting the critical infrastructures from terrorism presents an enormous challenge. Recognizing that society cannot afford the costs associated with absolute protection, it is necessary to identify and prioritize the vulnerabilities in these infrastructures. This article presents a methodology for the identification and prioritization of vulnerabilities in infrastructures. We model the infrastructures as interconnected digraphs and employ graph theory to identify the candidate vulnerable scenarios. These scenarios are screened for the susceptibility of their elements to a terrorist attack, and a prioritized list of vulnerabilities is produced. The prioritization methodology is based on multiattribute utility theory. The impact of losing infrastructure services is evaluated using a value tree that reflects the perceptions and values of the decisionmaker and the relevant stakeholders. These results, which are conditional on a specified threat, are provided to the decisionmaker for use in risk management. The methodology is illustrated through the presentation of a portion of the analysis conducted on the campus of the Massachusetts Institute of Technology.

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Risk-based spacecraft fire safety experiments

Cited by 14 publications

References 14 publications

Ignition and Flame Propagation of Externally Heated Electrical Wires with Electric Currents

Ignition and Flame Propagation of Externally Heated Electrical Wires with Electric Currents

Nitrogen as an environmentally friendly suppression agent for aircraft cargo fire safety

A Screening Methodology for the Identification and Ranking of Infrastructure Vulnerabilities Due to Terrorism

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