Numerical investigation of the fatal 1985 Manchester Airport B737 fire

In this paper, fire and evacuation computer simulations are used to reconstruct the 1985 Manchester Airport B737 fire that resulted in the loss of 55 lives. First the actual fire and evacuation are reconstructed. Secondly, the impact of exit opening times and external wind on the fire and evacuation are investigated. Finally, the potential benefit offered by modern materials is evaluated. The results suggest that the number of fatalities could have been reduced by 87% had the forward right exit not malfunctioned and by 36% had the right over-wing exit been opened without delay. Furthermore, given the fuel pool size and location, a critical wind speed of 1.5 m/s is necessary to cause the fire plume to lean onto the fuselage eventually resulting in fuselage burn-through. Finally, it is suggested that the use of modern cabin materials could have made a significant difference to the fire development and survivability

Modelación y simulación de comportamientos humanos en situaciones de emergencia en un call center: una revisión crítica de literatura

En este trabajo se presenta una revisión de literatura de la modelación y simulación de comportamientos humanos en situaciones de emergencia en un call center. Para la búsqueda se consultaron bases de datos bibliográficas como Scopus, Sciencedirect, y Emerald entre otras, en las que, tras realizar un proceso estructurado de revisión bibliográfica, se encontraron más de 50 artículos. La clasificación de los artículos encontrados se hizo en cuatro categorías: (1) tipo de análisis, (2) tipo de emergencia, (3) tipo de entorno y (4) tipo de comportamiento. En los tipos de análisis de los artículos se encontró que la mayoría se enfocan en estudios estadísticos y heurísticos; los entornos analizados se enfocan principalmente en edificios de oficinas y de otros tipos como vivienda, y locales comerciales; el evento más analizado es el incendio; y en cuanto al tipo de comportamiento se encuentra que son diversas las formas en las cuales las personas reaccionan ante eventos de emergencia. Se encuentra en la literatura consultada la caracterización de los posibles comportamientos de las personas que pueden tener en un evento de emergencia, esto con el fin de tener una aproximación de tales comportamientos dentro de la simulación de eventos de emergencia.

Modelación y simulación del comportamiento humano en situaciones de emergencia

RESUMEN: Durante eventos de emergencia en entornos laborales es complejo determinar cuál será la reacción o de qué forma se comportarán las personas. En este trabajo se busca evaluar el impacto del comportamiento de las personas en eventos de emergencia en centros de servicio, estableciendo modelos que expliquen situaciones similares en diferentes escenarios para luego, determinar el impacto del comportamiento de las personas en momentos de evacuación y evaluar políticas que mitiguen los impactos negativos que puedan existir en dichas situaciones. En este trabajo se toma como referencia los datos de un call center de una Institución Prestadora de Servicios de Salud (IPS) de Medellín, en el cual se estudia el impacto del comportamiento de las personas en una emergencia, teniendo en cuenta la norma colombiana en cuanto a seguridad laboral. Los resultados evidencian que la velocidad de evacuación depende de diversos factores, entre ellos el comportamiento de las personas en el evento de emergencia.ABSTRACT: During emergency events in work environments, it is complex to determine what the reaction will be or how people will behave. This paper aims to evaluate the impact of the behavior of people in emergency events in service centers, establishing models that explain similar situations in different scenarios, then determine the impact of people's behavior in evacuation moments and evaluate policies that mitigate the negative impacts that may exist in such situations. In this study, the data of a call center of a Health Services Provider Institution (IPS) in Medellín is taken as reference, in which the impact of the behavior of the people in an emergency is studied, taking into account the Colombian norm in terms of job security. The results show that the evacuation rate depends on several factors, including the behavior of the people in the emergency event

Flood-pedestrian simulator: an agent-based modelling framework for urban evacuation planning

Agent-Based Modelling (ABM) is an increasingly used approach for characterisation of human behaviour in evacuation simulation modelling. ABM-based evacuation models used in flood emergency are developed mostly for vehicular scenarios at regional scale. Only a few models exist for simulating evacuations of on-foot pedestrians responding to floods in small and congested urban areas. These models do not include the heterogeneity and variability of individuals’ behaviour influenced by their dynamic interactions with the floodwater properties. This limitation is due to the modelling restrictions pertaining to the computational complexity and the modelling flexibility for agent characterisation. This PhD research has aimed to develop a new ABM-based pedestrian evacuation model that overcomes these challenges through an ABM platform called Flexible Large-scale Agent Modelling Environment for the Graphics Processing Units (FLAME GPU). To achieve this aim, a hydrodynamic model has been integrated into a pedestrian model within the FLAME GPU framework. The dynamic interactions between the flood and pedestrians have been formulated based on a number of behavioural rules driving the mobility states and way-finding decisions of individuals in and around the floodwaters as well as the local changes in the floodwater properties as a result of pedestrians’ crowding. These rules have been progressively improved and their added value has been explored systematically by diagnostically comparing the simulation results obtained from the base setup and the augmented version of the model applied to a synthetic test case. A real-world case study has been further used to specifically evaluate the added value of rules relating the individuals’ way-finding mechanism to various levels of flood-risk perception. The findings from this research have shown that increasing the level of pedestrians’ heterogeneity and the effect of pedestrians’ crowding on the floodwater hydrodynamics yield to a considerably different prediction of flood risk and evacuation time. Besides, accounting for pedestrians’ various levels of flood-risk perception has been found to be one determinant factor in the analysis of flood risk and evacuation time when there are multiple destinations. Finally, the sensitivity analysis on the simulation results have shown that the deviations in the simulation outcomes increases in line with the increase in the sophistication of human behavioural rules

An investigation of the changing commercial airline passenger anthropometry and its effects on aircraft safety and performance

At first glance, anthropometry and aviation would appear to be unrelated to one another; however, an important relationship exists between them. Aircraft are vehicles that are primarily designed to transport people across long distances, and new aircraft types with enhanced design features are continually being developed, built then entering the aviation market for global airline service. These enhancements to human–machine interfaces ensure continued safety and efficiency, improve performance and prolong the life cycle of components. However, they often do not consider the effect of the changing anthropometric characteristics of the passenger. The media and the medical literature have identified increasing global trends in the average weight and height of passengers, as well as other anthropometrical and biometrical measures. However, the majority of these studies have been limited to exploring the ramifications primarily from the perspective of passengers’ experience. This thesis is the first to explore the explicit relationship between commercial passengers’ anthropometry and aircraft safety, design and performance. It highlights the importance of considering passengers’ anthropometric characteristics from a holistic perspective, and it identifies gaps for future research. A thorough search of the available literature shows that this topic has received little attention, thereby demonstrating the need for this research. Most literature to date has revealed that there is limited knowledge regarding the ramifications of changes in passengers’ anthropometry. The two main areas of focus of this research are aircraft performance and aircraft safety. Aircraft Performance All aircraft are designed to ensure optimal performance during flight, with key flight characteristics interacting and changing depending on the aircraft’s weight. However, the correct estimation of the passenger component of that weight is often overlooked when compared with the weight of freight or fuel. Passenger weight is typically set to a predetermined value by aviation regulators; therefore, it does not reflect the true weight of the passengers onboard. In some cases, the standard weights issued by the regulator are out of date and do not reflect current society trends in obesity. Hence, the research component that addresses aircraft performance explores the effect of passenger weight attributes and obesity on several aircraft performance characteristics. The numerical performance analysis uses spreadsheets to calculate the various performance objectives related to specific phases in the flight. The performance literature shows that similar methods have been used to analyse data, predominantly for studies regarding aircraft flight attributes. The key benefit of spreadsheets is that they allow changes to be made to initial base parameters such as passenger weight, aircraft data and initial conditions. It was concluded that Western countries with a higher prevalence of obesity and lower standard passenger weights might overestimate performance characteristics such as fuel usage, range, landing and take-off performance. Similarly, countries (predominantly African) with lower obesity prevalence underestimate these performance characteristics because they rely on standard weights from the Federal Aviation Administration, European Aviation Safety Authority and Civil Aviation Authority United Kingdom. Overall performance characteristics for any aircraft type considered in this study will be significantly affected if existing obesity growth forecasts for the next few decades are proven to be accurate. This justifies the need for more accurate regulations and improved flight operational procedures. Safety—Emergency Egress The design of commercial passenger aircraft must take into consideration the certification requirement that all occupants should be able to evacuate from the cabin within 90 seconds in an emergency. Manufacturers are required to demonstrate compliance with this regulatory requirement using the aircraft to be certified. There is a significant risk of injury to participants when conducting evacuation tests. To determine whether passengers can evacuate safely from the aircraft within 90 seconds, manufacturers may use computer-aided simulations to mitigate risks to participants. This has an added benefit of allowing customisation of the profiles of the individual models used. The research component in this study involved simulations using two aircraft types: narrow-body (180 seats) and wide-body (399 seats) aircraft. Both aircraft are modelled using the multi-application egress simulation software package Pathfinder. Multiple scenarios are explored and consist of different levels of obesity prevalence ranging from the control parameter of 55% to higher levels of obesity prevalence that mirror obesity growth forecasts. These scenarios form three situations in which different body mass index (BMI) groups have greater prevalence in society: overweight (25<BMI<30), obese (30<BMI<40) and morbid obesity (BMI>40). A total of 98 different anthropometric profiles based on age, gender and BMI were created. Data from the National Health and Nutrition Examination Survey were used for the model in this study. A total of 40 repeated simulations were conducted for each scenario. The results showed that when obesity prevalence increases, the evacuation time of both aircraft types also increases. Increasing overall obesity by just 5% can lead to an increase in the egress time of approximately two seconds for the wide-body aircraft scenario. Further, regression analysis for both aircraft demonstrated that the variables of BMI and distance to exit have strong statistical significance for overall evacuation time. A sensitivity study was conducted for delay time, which represents the sit-to-stand time of the occupant. This study was needed because Pathfinder could not allocate delay times to individual profiles, but only to the overall occupant population. The control scenario formed the basis of this study, and the control delay time standard deviation was used as a factor to change the delay time. The results showed that the delay time did not affect the egress time, except for the highest delay time scenario of six standard deviations above the control time. A bus emergency egress exercise was conducted in August 2018 to validate the model. This exercise involved conducting several evacuations from a bus and then replicating the trials in Pathfinder. The results were consistent between the simulations and the experimental exercise and showed that the model has an uncertainty interval of −4.5% to 6.5%