Design of a low-noise aeroacoustic wind tunnel facility at Brunel University

This paper represents the design principle of a quiet, low turbulence and moderately high speed aeroacoustic wind tunnel which was recently commissioned at Brunel University. A new hemi-anechoic chamber was purposely built to facilitate aeroacoustic measurements. The wind tunnel can achieve a maximum speed of about 80 ms-1. The turbulence intensity of the free jet in the potential core is between 0.1–0.2%. The noise characteristic of the aeroacoustic wind tunnel was validated by three case studies. All of which can demonstrate a very low background noise produced by the bare jet in comparison to the noise radiated from the cylinder rod/flat plate/airfoil in the air stream.The constructions of the aeroacoustic wind tunnel and the hemi-anechoic chamber are financially supported by the School of Engineering and Design at Brunel University

Airfoil noise reductions through leading edge serrations

This paper provides an experimental investigation into the use of leading edge (LE) serrations as a means of reducing the broadband noise generated due to the interaction between the aerofoil's LE and impinging turbulence. Experiments are performed on a flat plate in an open jet wind tunnel. Grids are used to generate isotropic homogeneous turbulence. The leading edge serrations are in the form of sinusoidal profiles of wavelengths, λ, and amplitudes, 2h. The frequency and amplitude characteristics are studied in detail in order to understand the effect of LE serrations on noise reduction characteristics and are compared with straight edge baseline flat plates. Noise reductions are found to be insignificant at low frequencies but significant in the mid frequency range (500 Hz-8 kHz) for all the cases studied. The flat plate results are also compared to the noise reductions obtained on a serrated NACA-65 aerofoil with the same serration profile. Noise reductions are found to be significantly higher for the flat plates with a maximum noise reduction of around 9 dB compared with about 7 dB for the aerofoil. In general, it is observed that the sound power reduction level (ΔPWL) is sensitive to the amplitude, 2h of the LE serrations but less sensitive to the serration wavelength, λ. Thus, this paper sufficiently demonstrates that the LE amplitude acts as a key parameter for enhancing the noise reduction levels in flat plates and aerofoils

'I know they are not trained in dementia': Addressing the need for specialist dementia training for home care workers

Global population ageing has meant a rapid increase in the numbers of older people with dementia, most of whom live in their own homes. Staying at home is an important determinant of health and well‐being. As care needs increase, the quality of community support which older people receive directly influences their capacity to remain in their own homes. While many are supported informally by family carers, formal support provided by home care workers often enables them to remain at home for longer period. However, providing community‐based care for people with dementia can be challenging. Workers often lack training in dementia‐specific care for clients with increasingly complex needs, and typically work without direct supervision. As the demand for person‐centred home care for people with dementia increases, specialist dementia training for home care workers is urgently needed. In this qualitative study, we used in‐depth interviews of a purposive sample, comprising 15 family carers and four older people with dementia, to understand the experience of receiving community care. Data analysis was guided by Braun and Clarke's approach to thematic analysis and revealed the following five overlapping themes, relating to home care workers’ understanding of dementia, person‐centred care, communication and rapport, mutual collaboration, and the influence of organisational constraints on continuity of care. Although participants acknowledged that service providers operated under challenging circumstances, they were frustrated with home care workers’ lack of dementia knowledge and inconsistent staff rostering. Conversely, an understanding of the lived experience of dementia, effective communication and rapport, and continuity of care contributed significantly to a positive experience of receiving care. The findings of this study will be used to inform the essential elements of a training program aimed at enabling and empowering a skilled, specialist home care workforce to support older people with dementia to live well at home for as long as possible

What constitutes 'good' home care for people with dementia? An investigation of the views of home care service recipients and providers

BACKGROUND: Our objective was to explore what people receiving and providing care consider to be ‘good’ in-home care for people living with dementia. METHODS: We conducted 36 in-depth interviews and two focus groups with key stakeholders in Australia in the first quarter of 2018. Participants included those receiving care (4 people living with dementia, 15 family carers) or providing care (9 case managers, 5 service managers, 10 home care workers). Qualitative thematic analysis was guided by Braun and Clarke’s six-step approach. RESULTS: Consensus was reached across all groups on five themes considered as important for good in-home dementia care: 1) Home care workers’ understanding of dementia and its impact; 2) Home care workers’ demonstrating person-centred care and empathy in their care relationship with their client; 3) Good relationships and communication between care worker, person with dementia and family carers; 4) Home care workers’ knowing positive practical strategies for changed behaviours; 5) Effective workplace policies and workforce culture. The results contributed to the co-design of a dementia specific training program for home care workers. CONCLUSIONS: It is crucial to consider the views and opinions of each stakeholder group involved in providing/receiving dementia care from home care workers, to inform workforce training, education program design and service design. Results can be used to inform and empower home care providers, policy, and related decision makers to guide the delivery of improved home care services. TRIAL REGISTRATION: ACTRN 12619000251123

What constitutes ‘good’ home care for people with dementia? An investigation of the views of home care service recipients and providers

BACKGROUND: Our objective was to explore what people receiving and providing care consider to be 'good' in-home care for people living with dementia. METHODS: We conducted 36 in-depth interviews and two focus groups with key stakeholders in Australia in the first quarter of 2018. Participants included those receiving care (4 people living with dementia, 15 family carers) or providing care (9 case managers, 5 service managers, 10 home care workers). Qualitative thematic analysis was guided by Braun and Clarke's six-step approach. RESULTS: Consensus was reached across all groups on five themes considered as important for good in-home dementia care: 1) Home care workers' understanding of dementia and its impact; 2) Home care workers' demonstrating person-centred care and empathy in their care relationship with their client; 3) Good relationships and communication between care worker, person with dementia and family carers; 4) Home care workers' knowing positive practical strategies for changed behaviours; 5) Effective workplace policies and workforce culture. The results contributed to the co-design of a dementia specific training program for home care workers. CONCLUSIONS: It is crucial to consider the views and opinions of each stakeholder group involved in providing/receiving dementia care from home care workers, to inform workforce training, education program design and service design. Results can be used to inform and empower home care providers, policy, and related decision makers to guide the delivery of improved home care services. TRIAL REGISTRATION: ACTRN 12619000251123

Numerical simulation of turbulence interaction noise applied to a serrated airfoil

Turbulent wakes generated by turbofan blades and interacting with the outlet guide vanes are known to bemainly contributing to broadband noise emission of aero-engines at approach conditions. Analytical approaches,such as the well-known Amiet's model can be adopted to estimate the noise generated by turbulent flowsimpacting thin airfoils, but they are limited by the flat-plate assumptions. The development of numericalmethods allowing more complex geometries and realistic flows is required. The method, described in the presentpaper, is based on a CAA code solving the nonlinear Euler equations. The upstream turbulence is synthesizedfrom a stochastic model and injected into the computational domain through an adapted boundary condition. It isfirst validated in 2D and 3D against academic flat plate configurations by comparison with Amiet solutions(exact in such cases). Then, 3D computations are applied to simulate the effect of a passive treatment (leadingedge serrations) aiming at reducing turbulence interaction noise of an isolated airfoil studied in the framework ofEuropean project FLOCON. First calculations on baseline conditions are shown to be able to reproduce themeasured spectra and far-field directivities, and the acoustic performances of the serrations (3-4 dB PWLreduction) are fairly well assessed too

Airfoil noise reductions through leading edge serrations

This paper provides an experimental investigation into the use of leading edge (LE) serrations as a means of reducing the broadband noise generated due to the interaction between the aerofoil’s LE and impinging turbulence. Experiments are performed on a flat plate in an open jet wind tunnel. Grids are used to generate isotropic homogeneous turbulence. The leading edge serrations are in the form of sinusoidal profiles of wavelengths, ?, and amplitudes, 2h. The frequency and amplitude characteristics are studied in detail in order to understand the effect of LE serrations on noise reduction characteristics and are compared with straight edge baseline flat plates. Noise reductions are found to be insignificant at low frequencies but significant in the mid frequency range (500 Hz–8 kHz) for all the cases studied. The flat plate results are also compared to the noise reductions obtained on a serrated NACA-65 aerofoil with the same serration profile. Noise reductions are found to be significantly higher for the flat plates with a maximum noise reduction of around 9 dB compared with about 7 dB for the aerofoil. In general, it is observed that the sound power reduction level (?PWL) is sensitive to the amplitude, 2h of the LE serrations but less sensitive to the serration wavelength, ?. Thus, this paper sufficiently demonstrates that the LE amplitude acts as a key parameter for enhancing the noise reduction levels in flat plates and aerofoils

EXPÉRIENCES DE BASE SUR LA DIRECTIVITÉ DU RAYONNEMENT SONORE ÉMIS PAR UN TURBOMOTEUR

Des expériences acoustiques de base ont été menées en chambre anéchoïque, afin de mieux comprendre les phénomènes physiques liés à la géométrie de l'entrée d'air de turbomoteurs d'hélicoptères. Deux maquettes d'entrée d'air cylindrique ont été étudiées ; le bruit de compresseur est simulé à l'aide d'un synthétiseur de modes tournants. Les analyses modales et les directivités mesurées servent de comparaison aux premiers calculs existants.Basic acoustic experiments have been performed in an anechoic chamber, in order to analyse the influence of the geometry of turboshaft engine air intake on sound propagation and radiation. Two air intake models have been studied. The compressor noise is simulated by a spinning mode synthesizer. Modal analysis and experimental directivities are compared to some calculations