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The flow field and body aerodynamic loads on the DrivAer reference model have been extensively investigated since its introduction in 2012. However, there is a relative lack of information relating to the models wake development resulting from the different rear-body configurations, particularly in the far-field. Given current interest in the aerodynamic interaction between two or more vehicles, the results from a preliminary CFD study are presented to address the development of the wake from the Fastback, Notchback, and Estateback DrivAer configurations. The primary focus is on the differences in the far-field wake and simulations are assessed in the range up to three vehicle lengths downstream, at Reynolds and Mach numbers of 5.2 × 10 6 and 0.13, respectively. Wake development is modelled using the results from a Reynolds-Averaged Navier-Stokes (RANS) simulation within a computational mesh having nominally 1.0 × 10 7 cells. This approach was chosen to reflect a simple, cost-effective solution, using an industry-standard CFD solver. Each vehicle configuration has a smooth underbody, with exterior rear-view mirrors. The computational modelling includes a ground simulation set, and all simulations are for zero freestream yaw angle. A mesh sensitivity study was undertaken and the simulation validated against published experimental data for the body pressure distribution and aerodynamic drag. Critical assessment of the results highlights the benefits of focussed mesh refinement and specific numerical strategies for optimum performance of the CFD solver. Comparison of the far-field aerodynamic wake for the three model configurations exhibits significant differences in both extent and structure within the wake region up to three vehicle lengths downstream of the base. Total pressure loss coefficient is used as the primary aerodynamic parameter for analysis. The study is an element of a larger programme related to vehicle wake simulation and strategies are identified for possible wake modelling using simplified, computationally and experimentally efficient, shapes.

Recent work has demonstrated the use of sparse sensors in combination with the proper orthogonal decomposition (POD) to produce data-driven reconstructions of the full velocity fields in a variety of flows. The present work investigates the fidelity of such techniques applied to a stalled NACA 0012 aerofoil at $ {Re}_c=75,000 $ at an angle of attack $ \alpha ={12}^{\circ } $ as measured experimentally using planar time-resolved particle image velocimetry. In contrast to many previous studies, the flow is absent of any dominant shedding frequency and exhibits a broad range of singular values due to the turbulence in the separated region. Several reconstruction methodologies for linear state estimation based on classical compressed sensing and extended POD methodologies are presented as well as nonlinear refinement through the use of a shallow neural network (SNN). It is found that the linear reconstructions inspired by the extended POD are inferior to the compressed sensing approach provided that the sparse sensors avoid regions of the flow with small variance across the global POD basis. Regardless of the linear method used, the nonlinear SNN gives strikingly similar performance in its refinement of the reconstructions. The capability of sparse sensors to reconstruct separated turbulent flow measurements is further discussed and directions for future work suggested.

A modern benchmark for passenger cars-DrivAer modelhas provided significant contributions to aerodynamics-related topics in automotive engineering, where three categories of passenger cars have been successfully represented. However, a reference model for highperformance car configurations has not been considered appropriately yet. Technical knowledge in motorsport is also restricted due to competitiveness in performance, reputation and commercial gains. The consequence is a shortage of open-access material to be used as technical references for either motorsport community or academic research purposes. In this paper, a parametric assessment of race car aerodynamic devices are presented into four groups of studies. These are: (i) forebody strakes (dive planes), (ii) front bumper splitter, (iii) rear-end spoiler, and (iv) underbody diffuser. The simplified design of these add-ons focuses on the main parameters (such as length, position, or incidence), leading to easier manufacturing for experiments and implementation in computational studies. Consequently, a proposed model aims to address enclosed-wheel racing car categories, adapting a simplified, 35% scaled-model DrivAer Fastback shape (i.e. smooth underbody, no wheels, and with side mirrors). Experimental data were obtained at the 8ft x 6ft Cranfield Wind Tunnel using an internal balance for force and moment measurements. The aerodynamic performance of each group of add-on was assessed individually in a range of ride heights over a moving belt. All cases represent the vehicle at a zero-yaw condition, Reynolds number (car length-based) of 4.2 × 10 6 and Mach number equal to 0.12. The proposed high-performance configuration (DrivAer hp-F) was tested and a respective Reynolds number dependency study is also provided. In line with the open-access concept of the DrivAer model, the CAD geometry and experimental data will be made available online to the international community to support independent studies.

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RESUMOA biomineralização é uma alteração química em um ambiente através de atividade microbiana que resulta na precipitação de minerais, sendo um fenômeno amplamente distribuído na natureza. Na precipitação de carbonato de cálcio induzida microbiologicamente (MICP, do inglês microbially induced calcium carbonate precipitation), a urease apresenta papel importante ao hidrolisar a ureia, por uma grande variedade de micro-organismos capazes de produzir elevados níveis desta enzima. Existem diferentes polimorfos do cristal de carbonato de cálcio e a estrutura que é formada depende do tipo da fonte de cálcio utilizada, período de incubação e atividades metabólicas referentes à espécie microbiana avaliada. A MICP é uma alternativa promissora e ambientalmente amigável para as tecnologias de remediação atuais e convencionais capazes de resolverem problemas ambientais em campos multidisciplinares. Várias aplicações como aumento da qualidade e da melhoria das propriedades de materiais de construção, remoção de metais potencialmente tóxicos e radionucleotídeos e sequestro de dióxido de carbono atmosférico têm sido discutidas. PALAVRAS-CHAVE: Biomoneralização, carbonato de cálcio, construção civil, MICP, urease. CALCIUM CARBONATE BIOPRECIPITATION BY UREOLYTIC BACTERIA AND ITS APPLICATIONSABSTRACT Biomineralization is a chemical change in environment through the microbial activity that results in the precipitation of minerals, being a phenomenon widely spread in nature. In microbially induced carbonate precipitation (MICP), ureases plays an important role in hydrolyzing urea by a large variety of microorganisms capable of producing high levels of this enzyme. There are different polymorphs of calcium carbonate crystal and the structure that is formed depends on the type of calcium used, the incubation time and metabolic activities of the evaluated microbrial species.

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