In the planning process for high rise buildings, it is common practice to carry out physical or numerical simulations of the wind flow around such buildings, in order to establish the acceptability or otherwise of these wind conditions for a range of pedestrian activities such as sitting, slow walking, rapid walking etc. It is less common to assess the wind conditions in terms of pedestrian safety in high winds, and the safety of cyclists and light high sided vehicles is never usually considered. The need for such considerations has become tragically obvious in a recent incident in Leeds, where a pedestrian was killed after a lorry blew over due to winds around a new high rise structure. When pedestrian safety is considered, this is usually in terms of a simple wind speed criterion that does not take into account human behaviour and does not allow for a proper risk analysis. This project will consider these issues with a view to establishing a robust methodology for calculating the risk of a pedestrian, cyclist or high sided vehicle accident in high wind conditions around high rise building. Full scale measurements will be carried out around a high rise building on the University of Birmingham campus to measure the turbulent nature of the flow around such buildings, since it is these highly turbulent flows that are of relevance to the issue of safety rather than the mean wind flows. Wind tunnel tests and CFD calculations will be carried out of the same building to assess the adequacy of these techniques for predicting the highly turbulent flows of relevance to the problem under discussion. Trials will then be carried out using instrumented volunteers of a range of age and size, who will walk or cycle around the structure during windy periods, and their behaviour will be assessed both quantitatively and qualitatively, in order to develop probability distributions of the wind speed at which incipient instability of pedestrians occurs. In addition measurements will be made of the cross wind forces on scale models of typical high rise vehicles using the University of Birmingham moving model TRAIN rig, with highly turbulent cross wind conditions, again to develop probability distributions of wind speeds for incipient instability. The probability distributions thus obtained will then be used, with wind speed probability distributions, to develop a calculation methodology to determine the variation of accident risk around high rise structures.

The world is witnessing rapid urbanisation, where a large percentage of its population is expected to live within urban environments - circa 70% - by 2050 [1]. The main solution to urban immigration has been to construct tall buildings (TBs), which allow for a high-density population (and commercial activities) to reside in the hearts of our cities. However, recent years have witnessed increasing concerns regarding public health and wellbeing in dense urban environments. For instance, it is known that the urban heat island effect, where urban areas are typically some degrees hotter than the surrounding rural areas, can contribute to death rates during heatwaves [2]. To exacerbate these issues, as recognised by the London Plan [3], ''some climate change is inevitable..." and this is likely to increase the frequency and severity of extreme weather events, and the consequent urban health risks. The current COVID-19 crisis has also highlighted the importance of predicting pathogen dispersion and of efficient indoor/outdoor ventilation in urban areas [4]. It is, therefore, in the public interest to build healthy and sustainable urban environments by ensuring that air quality, transport of pollutant emissions, and the microclimate within cities (e.g. winds, temperatures, pollutant concentrations, and anthropogenic heat) do not reach unsustainable levels from poor urban development planning and lack of strategic directions. Recent initiatives are now promoting research on urban environmental health and sustainability (e.g. Public Health England's project Healthy-Polis). Despite the likely effects of the proliferation of tall structures in exacerbating some of the problems discussed above, current weather and air quality models do not cater for TBs and their long-lasting effects on the winds and temperature fields within urban neighbourhoods. This mostly relates to the dominant small scales of the phenomena under examination, in contrast to the spatial resolution that these models typically achieve (i.e. of the order of hundreds of metres) within the constraints of state-of-the-art computer power, resource availability, and turnaround time. On the other hand, the spatial resolution of computational fluid dynamics methods used in academia is much higher i.e. appropriate to resolve the presence of these urban towers. However, these research simulations often lack much of the physics needed to adequately capture real environmental flows (e.g. atmospheric conditions, heat exchange), and are generally run over much smaller domains. Hence, there is a dual need for more realistic detailed simulations and better parametrisations for larger-scale operational models, with the former informing development of the latter. To overcome these limitations, this project will employ a synergy of wind-tunnel tests, field observations, high-fidelity computer-aided analysis, and theoretical models. This will allow us to (i) understand the dependence of wind and temperature fields on the geometric parameters describing TBs both in isolation and as a cluster, and (ii) to develop parametrisations and open-source models that can be readily available to policymakers and regulators to assist them in building more resilient urban environments. The aim is to develop publicly available fast turnaround models that describe the effect of TBs on the quantities of interest for users with different levels of sophistication. This will include "rule-of-thumb" design principles aimed at local authorities and technical model parametrisations suitable for implementation in larger numerical weather prediction and air quality software to serve the professional and operational modelling community. References [1] Revision of World Urbanization Prospect (2018). DESA, UN. [2] Vardoulakis et al. (2016). Environmental Health 15, S30. [3] The London Plan (2017). Greater London Authority. [4] ECDC Tech. Report (2020). European Centre for Disease Prevention and Control.

Mitigating unwanted vibration in mechanical structures via effective and reliable approaches is an important and difficult part of the design process. For example, a good balance between ride comfort and handling for passenger vehicles, the need to build taller and more slender buildings while maintaining good dynamic performances under wind and earthquake disturbances, and the trade off between maintaining straight running stability and reducing track wear when curving for railway vehicles, have all attracted much research from both academia and industry. In the current drive for more flexible, lightweight and more efficient structures, enhancing the capability of vibration suppression systems has become even more important. The introduction of the inerter concept has from theoretical point of view fundamentally enhanced the capability of passive vibration suppression systems. Significant theoretical performance advantages for a wide range of mechanical structures have been identified. However, when working on real applications, we face the obstacle of inadequate knowledge of the dynamic properties of physical inerter realisations. This project will establish accurate fluid based inerter models and demonstrate the potential superiority of such designs for passenger cars, tall buildings and railway vehicles through case studies developed in close collaboration with industrial project partners. The proposed work will enable the widespread uptake of fluid inerter based vibration suppression design techniques and constitute a major step towards wide spread application in multiple industrial sectors including road and rail transportation, civil engineering as well as aerospace engineering. The resulting improvements in the UK's capability for advanced design will greatly assist the high-end manufacturing industry to maintain its competitive edge.

Local and global consequences of climate change (enhanced urban heat islands, worsening environmental conditions) affect most of the world's urban population, but only recently have cities been represented, albeit crudely, in weather forecast models. To manage and develop sustainable, resilient and healthy cities requires improved forecasting and observations that cross neighbourhood-influenced scales which the next generation weather forecast models need to resolve. ASSURE addresses the critical issue of which processes need to be parameterised, and which resolved, to capture urban heterogeneity in space and time. We will advance understanding to develop new approaches and parameterisations for larger-scale urban meteorological and dispersion models by combining the results of field observations, high-resolution numerical simulations and wind tunnel experiments. Field work and modelling will focus on Bristol, as its physical geography provides suitably high levels of complexity and allows whole-city approaches. With mid-sized cities being large sources of greenhouse gases, and where large numbers of people live, it is critical agencies can provide predictions of weather and climate variability across cities of this scale as they need this information to manage and provide their services. ASSURE will include idealised simulations and theoretical analyses to ensure generic applicability. The ASSURE objectives are: * To understand how sources of urban heterogeneity (physical setting, layout of buildings and neighbourhoods, human activities) combine to influence the urban atmosphere in space and time. * To quantify effects of urban heterogeneity at different scales (street to neighbourhood, to city and beyond) on flow, temperature, moisture and air quality controlling processes and to determine how these processes interact. * To develop a theoretical framework that captures key processes and feedbacks with reduced complexity to aid mesoscale and larger model parameterisations. * To inform the development priorities of current weather and climate models that have meso-scale capabilities and are used in decision-making processes (e.g. integrated urban services). The ASSURE high-fidelity simulations and carefully designed experiments will allow us to explore implications of urban heterogeneity in isolated and combined configurations; interpret and integrate field observations (e.g. 3D meteorological and city-scale tracer dispersion experiments); integrate different approaches to understand the magnitude, source, and geographical extent of uncertainties in process models at different scales; synthesize the new knowledge to conduct theoretical analyses; develop algorithms reflecting this analysis. Novel in ASSURE are simulations resolving street to city-scale features that are linked to mesoscale models; field observations capturing vertical and horizontal variations in the urban boundary- and canopy-layers, including novel multi-source gas tracer experiments; and wind tunnel simulations across atmospheric stabilities and model resolution. New insights will be gained on the role of variations in the building morphology (or form), local topography, and human activities (e.g. waste heat, and AQ emissions). ASSURE will produce detailed datasets; in-depth understanding across the scale of atmospheric processes involved; high-fidelity multiscale urban modelling tools; theoretical models taking account of multiscale effects; improved assessment of current meso-scale model skill and the data used by practitioners to explore future urban scenarios as city form and function change. We will work with local and international organisations and companies to ensure the project benefits a broad range of society. They include: Avon Longitudinal Study of Parents and Children, CERC, COWI, ECMWF, Met Office, Delft University of Technology, Stanford University, University Hannover, RWDI, Surrey Sensors and UKCRIC.

Poor air quality is widely recognised to affect human health and wellbeing. Cumulative exposure to pollutants throughout the life course is a determinant for numerous long term health conditions including dementia, heart disease and diabetes, Short term high exposures are shown to exacerbate conditions such as asthma and COPD, increase risks of heart attacks and stroke and influence respiratory infections. The very young, very old and those with pre-existing conditions are most at risk and inequality further increases this; the poorest in society often live in the lowest quality housing in the most polluted areas. Human exposure to air pollutants occurs in both indoor and outdoor environments. Urban air pollution results from a combination of local outdoor sources (e.g. transport, combustion, industry) and regional and large scale atmospheric transport of pollutants. We spend up to 90% of our time indoors and indoor air quality is therefore a significant part of human exposure. Indoor air quality is influenced by the climate, weather and air quality in the external environment in addition to local indoor sources (e.g. microorganisms, chemicals cleaning and personal care, cooking, industry processes, emissions from building materials, heating and mechanical systems) and the building design and operation. In all cases it is the airflows within and between indoor and outdoor locations that enables the transport of pollutants and ultimately determines human exposures. Understanding airflows is therefore at the heart developing effective mitigating actions, particularly in cases where there is limited ability to remove a pollutant source. Being able to predict the influence of airflows enables understanding of how pollutants are likely to move within and between buildings in a city, both under normal day-to-day conditions and in response to emergencies such as heatwaves or wildfires. With the right computational and measurement tools it is then possible to change the design or management of city neighbourhoods enabling better urban flows to reduce exposure to pollutants and also to innovate new ventilation solutions to control the indoor environment in buildings. While there are a number of approaches that already enable assessment of urban flows and indoor flows, these aspects are not currently considered together in an integrated way or focused on optimising environments for health. The Future Urban Ventilation Network (FUVN) aims to address this by defining a new holistic methodology - the Breathing City. This will define a new integrated assessment approach that considers coupled indoor-outdoor flows together to minimise exposure for people within a neighbourhood who are most at risk from the effects of poor air quality. The network will bring together people from a range of disciplines and areas of application with a common interest in improving urban and indoor airflows to improve health. Through small scale research and workshop activities we will advance the understanding of the fluid dynamics that determines the physics of this indoor-outdoor exchange. The network will develop a research programme to address technical gaps in modelling and measuring pollutant transport and how we can use this to determine long and short term exposures to a range of pollutants. We will work collaboratively with industry, policy makers and the public to understand how this approach could change city planning, building design guidance and community actions to enable health based future urban ventilation design and to "design out" health risks for people who are most vulnerable.