Browsing by Author "Escobar, Ignacio Camacho"

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    Simulating faults in a Boeing 737-200 environmental control system using a thermodynamic model
    (Prognostics and Health Management Society, 2020-01-13) Esperon Miguez, Manuel; Jennions, Ian K.; Escobar, Ignacio Camacho; Hanov, Nile
    The Environmental Control Systems (ECS), used to provide air to the aircraft cabin at the correct pressure and temperature, is a key driver of maintenance interruptions for military and civil aircraft. Fault detection is particularly difficult, due to the lack of instrumentation and the ability of the ECS’s control system to mask symptoms. Understanding how component degradation affects measurable thermodynamic parameters is key to developing a condition monitoring system for an ECS. This work focuses on the development of a thermodynamic model of a Boeing 737-200 ECS capable of simulating faults in three types of component: heat exchangers, valves, and water separators. The thermodynamic model has been validated using data collected on a ground-based instrumented B737-200 ECS. The results show how a thermodynamic model can be used to simulate the change of temperatures and pressures across the ECS when components degrade
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    Simulation of an aircraft environmental control system
    (Elsevier, 2020-01-09) Jennions, Ian; Ali, Fakhre; Miguez, Manuel Esperon; Escobar, Ignacio Camacho
    The environmental control system of a civil aircraft is a major driver of maintenance. Legacy systems, such as those on the Boeing 737, are particularly at risk, as they are not instrumented for health management. These systems degrade in operation and allow compensation within their operation for degrading components, until severe degradation or failure results. The required maintenance is then both costly and disruptive. The goal of this research is to produce a simulation environment that can model the aircraft environmental control system, in order that analysis for sensor placement and algorithms can be performed without extensive, and expensive, testing. A simulation framework called Simscape Environmental Control System Simulation under All Conditions has been proposed and implemented. It offers a library of components that can be assembled into specific aircraft environmental control system simulation configurations. It is capable of simulating the health state indicating parameters at sub-system and component levels under a wide-range of aircraft operating scenarios. The developed framework has been successfully implemented to simulate a Boeing 737-800 passenger air conditioner. Its verification and validation has been carried out against the actual data corresponding to a Boeing 737-800 passenger air conditioner operating at two different cruise operating points. An extensive comparison of the simulation is presented against the data for all the passenger air conditioner components. The overall acquired results suggest that changes in the aircraft ambient conditions can have a noticeable impact on the demanded passenger air conditioner outlet temperature, and a substantial impact on the heat transfer in the primary and secondary heat exchangers. The reported simulation capability serves as a first step towards formulating an environmental control system fault simulation and diagnostic solution.