Preliminary design of an in-flight icing condition measurement system for flight test instrumentation
Data
2022-05-26
Autores
Domingos, Juliano
Orientadores
Lourenção, Paulo
Tipo
Dissertação de mestrado profissional
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Ocorreram diversos acidentes com aeronaves causados por formação de gelo em voo, resultando em mortes de tripulantes e passageiros. O gelo acumulado sobre a aeronave resulta em mudança de características aerodinâmicas e de controle. Para evitar este tipo de acidente foram estabelecidos requisitos de projeto das aeronaves para enfrentarem condições de formação de gelo, sendo também necessária a realização de ensaios com protótipos em condições atmosféricas pré-determinadas para demonstrarem que o projeto satisfaz aqueles requisitos. Neste contexto, o objetivo deste trabalho foi desenvolver um projeto preliminar e um modelo de simulação de um novo sistema de instrumentação para ensaios de formação de gelo em protótipos de aeronaves. A pesquisa foi realizada na Unifesp em parceria com a Embraer. Para execução desta pesquisa foi utilizada a metodologia Design Science (DS) complementada pelo método de Desenvolvimento Integrado do Produto (DIP) e por conceitos de Systems Engineering (SE). A aplicação desta metodologia de pesquisa está neste documento estruturada nas fases de Definição, Desenvolvimento e Aprendizado. Inicialmente foi realizada uma revisão da literatura visando encontrar publicações e outros documentos mais relevantes e recentes sobre o tema. Além disso foram levantados tópicos relacionados a formação de gelo, ensaios em voo, certificação de aeronaves, instrumentação de ensaios em voo, processo de desenvolvimento de produto e resultados da revisão sistemática da literatura. Durante fase de definição, foram levantadas oportunidades de melhoria da arquitetura do sistema, tendo sido priorizadas a busca por sensores para medição de acúmulo de gelo na asa, novos sensores para medição de características das nuvens e melhorias no processamento de dados de ensaios. Os requisitos para o desenvolvimento do sistema foram definidos levando em consideração aspectos de certificação e opiniões de especialistas. Em seguida foi elaborado o projeto conceitual do sistema e apresentado a especialistas da empresa para avaliação. Com a aprovação do projeto conceitual, o projeto em nível de sistema foi executado de forma a considerar condições atmosféricas, condições de voo, dinâmica de sensores, aquisição e processamento de dados e apresentação de re- sultados. Os principais resultados deste trabalho são uma relação de sensores de gelo e tecnologias recomendados para uso comercial, além da construção de um modelo de simulação em MATLAB/Simulink® incluindo blocos representando nuvens em condições de formação de gelo, dinâmica de voo do avião e modelamento dos sensores de medição do Median Volume Diameter (MVD) e do Liquid Water Content (LWC) das gotas de água. O modelo também abrange um bloco de aquisição e processamento de dados de sensores com as informações de condições de formação de gelo dentro dos critérios e padrões de aeron- avegabilidade de aeronaves de transporte (Title 14 CFR Part 25). Os resultados de simulação de um voo de ensaio em condições de envelope de formação de gelo são apresentados em formas de gráficos e tabelas, além do cálculo de tempo equivalente. Finalmente são exibidas as conclusões da dissertação indicando as principais contribuições do autor e limitações do trabalho. Também são incluídas as reflexões sobre o desenvolvimento da pesquisa assim como sugestões de continuidade.
Aircraft accidents are sometimes due to in-flight icing that alters an aircraft’s aerodynamic and control characteristics. In the worst cases, this can lead to crew and passenger deaths. To prevent this type of accident, aircraft design requirements were established to reduce icing on aircraft. Tests with prototypes in pre-determined atmospheric conditions were de- veloped to meet appropriate safety requirements. The purpose of this study is to develop a preliminary design and simulation model of a new instrumentation system for icing tests on aircraft prototypes. The research was carried out at Universidade Federal de São Paulo (UNIFESP) in Brazil in partnership with Embraer, a Brazilian aerospace manufacturer. The present research used the Design Science (DS) methodology, the Integrated Product De- velopment (DIP) method, and Systems Engineering (SE) concepts, which are presented in three phases—Definition, Development, and Learning—in this study. Initially, a litera- ture review was conducted to discover recent publications and other documents on aircraft icing. Topics related to ice formation, flight tests, aircraft certification, flight test instrumen- tation, and product development process were also included. During the definition phase, opportunities to improve system architecture, the search for sensors to measure wing ice accumulation, new sensors to measure cloud characteristics, and improvements in test data processing were explored. The requirements for the development of the system were defined according to certification requirements and expert opinions. Following the definition phase, the system’s conceptual design was elaborated on and presented to the company’s special- ists for evaluation. With the conceptual design approved, a system-level design was carried out to consider atmospheric and flight conditions, sensor dynamics, data acquisition, and processing. The principal results of the study include a list of ice sensors and technologies recommended for commercial use, in addition to the construction of a simulation model in MATLAB/Simulink®, which includes blocks representing clouds in icing conditions, air- plane flight dynamics, and modeling Median Volume Diameter (MVD) and Liquid Water Content (LWC) measuring sensors for water droplets. The model also includes a sensor data acquisition and processing block with information on icing conditions within the crite- ria and airworthiness standards of transport aircraft (Title 14 CFR Part 25). The simulation results of a test flight under icing envelope conditions are presented graphically and in ta- bles, in addition to the equivalent time calculation. Finally, the conclusions are presented, which include the study’s limitations, its contributions to the field, and implications for and reflections on research development.
Aircraft accidents are sometimes due to in-flight icing that alters an aircraft’s aerodynamic and control characteristics. In the worst cases, this can lead to crew and passenger deaths. To prevent this type of accident, aircraft design requirements were established to reduce icing on aircraft. Tests with prototypes in pre-determined atmospheric conditions were de- veloped to meet appropriate safety requirements. The purpose of this study is to develop a preliminary design and simulation model of a new instrumentation system for icing tests on aircraft prototypes. The research was carried out at Universidade Federal de São Paulo (UNIFESP) in Brazil in partnership with Embraer, a Brazilian aerospace manufacturer. The present research used the Design Science (DS) methodology, the Integrated Product De- velopment (DIP) method, and Systems Engineering (SE) concepts, which are presented in three phases—Definition, Development, and Learning—in this study. Initially, a litera- ture review was conducted to discover recent publications and other documents on aircraft icing. Topics related to ice formation, flight tests, aircraft certification, flight test instrumen- tation, and product development process were also included. During the definition phase, opportunities to improve system architecture, the search for sensors to measure wing ice accumulation, new sensors to measure cloud characteristics, and improvements in test data processing were explored. The requirements for the development of the system were defined according to certification requirements and expert opinions. Following the definition phase, the system’s conceptual design was elaborated on and presented to the company’s special- ists for evaluation. With the conceptual design approved, a system-level design was carried out to consider atmospheric and flight conditions, sensor dynamics, data acquisition, and processing. The principal results of the study include a list of ice sensors and technologies recommended for commercial use, in addition to the construction of a simulation model in MATLAB/Simulink®, which includes blocks representing clouds in icing conditions, air- plane flight dynamics, and modeling Median Volume Diameter (MVD) and Liquid Water Content (LWC) measuring sensors for water droplets. The model also includes a sensor data acquisition and processing block with information on icing conditions within the crite- ria and airworthiness standards of transport aircraft (Title 14 CFR Part 25). The simulation results of a test flight under icing envelope conditions are presented graphically and in ta- bles, in addition to the equivalent time calculation. Finally, the conclusions are presented, which include the study’s limitations, its contributions to the field, and implications for and reflections on research development.