C.J. Ogugua
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3 records found
1
Environmental impacts in the civil aviation sector
Current state and guidance
The aviation sector contributes to environmental problems like climate change, resource depletion, and air pollution. We perform a systematic literature review of life cycle assessment studies to map the environmental impacts in the sector and provide methodological recommendations. The sector is divided into cross-cutting systems, namely aircraft, fuel and propulsion systems, and airports. Our review results confirm the sector's focus on climate change impacts. The mitigation strategies rely mostly on reducing CO2 emissions during aircraft operations, like implementing sustainable aviation fuels and prospective technologies or decreasing aircraft weight with lightweight components. We use review analyses to identify and discuss knowledge gaps, such as the assessment of noise impacts or non-CO2 flight emissions. Finally, aviation-specific recommendations are provided to LCA practitioners and aviation stakeholders with respect to data transparency and harmonization of results. Research needs, such as the development of characterization factors, are recommended to developers of life cycle impact assessment methods.
Autoclave curing is one of the most energy consuming processes in manufacturing carbon fibre reinforced polymers. In order to improve the energy efficiency, one needs to understand energy usage in an autoclave and factors that influence it. This work presents two thermodynamic based models for estimating energy consumption in an autoclave. The first model is an analytical approach based on simplified heat capacity equation. The second model combines the Multi-Relaxation-Time Lattice Boltzmann method (MRT LBM) with Fourier heat equation to simulate autoclave temperature flow and energy consumption. The output from the two models were compared to energy consumption data collected using a power meter. The estimated values from the MRT LBM method showed a better match with only 1% difference from the experimental value. Since the two models are parametric and scalable, a what-if analysis was carried out to investigate the influence of varying process parameters on autoclave energy consumption. Parameters including cure cycle, autoclave size and loading capacity.