145 research outputs found

    A preliminary numerical investigation of airborne droplet dispersion in aircraft cabins

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    The emergence of the novel coronavirus has led to a global pandemic which has led to the airline industry facing severe losses. For air travel to recover, airlines need to ensure safe air travel. In this paper, the authors have modelled droplet dispersion after a single breath from an index patient. Computational Fluid Dynamics (CFD) simulations are conducted using the k-w SST turbulence model in ANSYS Fluent. The authors have taken into consideration several parameters such as the size of the mouth opening, the velocity of the cabin air as well as the number of droplets being exhaled by the index patient to ensure a realistic simulation. Preliminary results indicate that after a duration of 20s, droplets from the index patient disperse within a 10 m2 cabin area. About 75% of the droplets are found the disperse for up to 2m axially behind the index patient. This could possess an enhanced risk to passengers sitting behind the index patient. Ultimately, this paper provides an insight into the potential of CFD to visualise droplet dispersal and give impetus to ensuring necessary mitigating measures can be taken to reduce the risk of infection through droplet dispersal

    A preliminary numerical investigation of airborne droplet dispersion in aircraft cabins

    Get PDF
    The emergence of the novel coronavirus has led to a global pandemic which has led to the airline industry facing severe losses. For air travel to recover, airlines need to ensure safe air travel. In this paper, the authors have modelled droplet dispersion after a single breath from an index patient. Computational Fluid Dynamics (CFD) simulations are conducted using the k-w SST turbulence model in ANSYS Fluent. The authors have taken into consideration several parameters such as the size of the mouth opening, the velocity of the cabin air as well as the number of droplets being exhaled by the index patient to ensure a realistic simulation. Preliminary results indicate that after a duration of 20s, droplets from the index patient disperse within a 10 m2 cabin area. About 75% of the droplets are found the disperse for up to 2m axially behind the index patient. This could possess an enhanced risk to passengers sitting behind the index patient. Ultimately, this paper provides an insight into the potential of CFD to visualise droplet dispersal and give impetus to ensuring necessary mitigating measures can be taken to reduce the risk of infection through droplet dispersal

    Optimization of thermo - physiological properties of structurally modified wool/polyester blended fabrics using desirability function

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    111-119The thermo-physiological properties of handloom fabrics produced with or without modified wool/polyester yarns in the weft has been studied. Yarn samples at different blend compositions are prepared according to mixture design at a different percentage of fibres using design expert software. The effect of percentage of different fibres, namely polyester, wool and PVA, on different thermo-physiological properties along with fabric properties obtained for different fibres after the dissolution of PVA component at yarn stage or fabric stage have also been studied. This paper also reports the potential of different fibres optimization to achieve maximum desirability for different thermo-physiological properties of treated (at yarn stage and fabric stage) and untreated fabrics with the help of desirability function. Treated fabrics at both stages show better thermo-physiological comfort properties as compared to untreated fabrics. In general, after dissolution of the PVA component both at the yarn stage or at the fabric stage, the treated fabric gives a higher value of thermal resistance, compressibility, drying capacity and water vapour permeability, while a lower value of air permeability and bending rigidity in comparison with untreated fabrics. Results of optimization for treated (at yarn stage and fabric stage) fabrics show higher overall desirability that can be achieved by using less percentage of wool fibres in case of treated fabrics (either at yarn stage or fabric stage)

    Effect of reflective practices on student learning in higher education—a real life approach

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    Validation of ideas are of paramount importance in STEM fields. Learning and converting ideas into practical application is the main purpose of technical education. Aviation is a highly safety sensitive field where confusion and mistakes are not acceptable. This brings serious challenges for academia that provides higher education in this field. A yearlong observation of the reflective practices was done at an Australian university while teaching aviation students to analyse outcomes of reflection on teaching and learning. Reflection provides a powerful opportunity to a teacher in improving teaching qualities and to identify training needs for enhancing teaching capabilities

    Optimization of thermo - physiological properties of structurally modified wool/polyester blended fabrics using desirability function 

    Get PDF
    The thermo-physiological properties of handloom fabrics produced with or without modified wool/polyester yarns in the weft has been studied. Yarn samples at different blend compositions are prepared according to mixture design at a different percentage of fibres using design expert software. The effect of percentage of different fibres, namely polyester, wool and PVA, on different thermo-physiological properties along with fabric properties obtained for different fibres after the dissolution of PVA component at yarn stage or fabric stage have also been studied. This paper also reports the potential of different fibres optimization to achieve maximum desirability for different thermo-physiological properties of treated (at yarn stage and fabric stage) and untreated fabrics with the help of desirability function. Treated fabrics at both stages show better thermo-physiological comfort properties as compared to untreated fabrics. In general, after dissolution of the PVA component both at the yarn stage or at the fabric stage, the treated fabric gives a higher value of thermal resistance, compressibility, drying capacity and water vapour permeability, while a lower value of air permeability and bending rigidity in comparison with untreated fabrics. Results of optimization for treated (at yarn stage and fabric stage) fabrics show higher overall desirability that can be achieved by using less percentage of wool fibres in case of treated fabrics (either at yarn stage or fabric stage)

    Effects of supervised reflective practices on teaching quality and student satisfaction in aviation education context

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    The higher education sector is under tremendous pressure in this era of automation and online learning. Consequently, major innovations in teaching and learning practices are required for the survival of universities. This paper explores the possibilities and benefits of supervised reflective learning for an academic to improve teaching quality and student satisfaction. In view of identifying a suitable leadership style for the supervision, this study discusses few theoretical concepts of leadership styles in higher education context while analysing the effects of leadership guidance on reflective learning of an academic and its outcomes. To this end, focused interviews of academic leaders, series of reflective exercises and a student survey were done choosing aerospace engineering discipline at a university. The results indicate that the reflective exercises under leadership supervision enhance teaching and learning quality of an academic, and they can also assist in improving student satisfaction

    A numerical investigation into the impact of icing on the aerodynamic performance of aerofoils

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    Aircraft wings and wind turbine blades are often subjected to harsh and cold climatic conditions. Icing is often observed on wing and blade surfaces in these cold climatic conditions. Wind turbine blades, in particular, are severely impacted by ice accretion which greatly hampers their performance and energy generation efficiency. Ice-accretion patterns are observed to vary with changes in temperature. As the temperature changes, the thickness of the ice accretion, the shape and location of ice-accretion vary greatly. In this paper, three different ice accretion patterns and their impact on the aerofoil efficiency have been investigated using the SS

    Drag reduction using biomimetic sharkskin denticles

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    This paper explores the use of sharkskin in improving the aerodynamic performance of aerofoils. A biomimetic analysis of the sharkskin denticles was conducted and the denticles were incorporated on the surface of a 2-Dimensional (2D) NACA0012 aerofoil. The aerodynamic performance including the drag reduction rate, lift enhancement rate, and Lift to Drag (L/D) enhancement rate for sharkskin denticles were calculated at different locations along the chord line of the aerofoil and at different Angles of Attack (AOAs) through Computational Fluid Dynamics (CFD). Two different denticle orientations were tested. Conditional results indicate that the denticle reduces drag by 4.3% and attains an L/D enhancement ratio of 3.6%
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