This paper presents the MSDEF (Modelo Simulador da Dispersão de Efluentes de Foguetes, in Portuguese) model, which represents the solution for time-dependent advection-diffusion equation applying the Laplace transform considering the Atmospheric Boundary Layer as a multilayer system. This solution allows a time evolution description of the concentration field emitted from a source during a release lasting time t r , and it takes into account deposition velocity, first-order chemical reaction, gravitational settling, precipitation scavenging, and plume rise effect. This solution is suitable for describing critical events relative to accidental release of toxic, flammable, or explosive substances. A qualitative evaluation of the model to simulate rocket exhaust clouds is showed.

An experimental study of the turbulent wake of a wind turbine model was realized at the “Joaquim Blessmann” wind tunnel of the UFRGS. The turbine model was developed at the Universidade de Caxias do Sul and it represents a three blade turbine characterized by a NACA 4412 aerodynamic profile. Measurements of the velocity fluctuations were realized by hot wire anemometry. Complexity of the turbulent flow is evaluated by mean and fluctuating velocity profiles. The influence of the incident flow turbulence and the flow reconstructing process are analyzed by the measurement results.

In this work, we report a numerical and statistical comparison between Advection-Diffusion Multilayer Method (ADMM) and Generalised Integral Laplace Transform Technique (GILTT) approaches to simulate a radioactive pollutant dispersion in the Atmospheric Boundary Layer (ABL) using micrometeorological parameters generated by Large Eddy Simulation (LES). To better describe the wind profile of the irregular ground level terrain, we considered the wind profile as a solution of the MesoNH model. We performed numerical simulations and comparisons against the data of Angra dos Reis-Brazil field experiments.

O estudo consiste na comparação dos resultados das simulações do WRF com medições de vento realizadas por uma torre anemométrica e dados fornecidos pelo Banco de Dados Meteorológicos para Ensino e Pesquisa (BDMEP) do Instituto Nacional de Meteorologia (INMET) por um período de 24 meses. Os resultados mostraram uma boa concordância entre os observados e os preditos pelo modelo, validando a metodologia aplicada na representação de ventos da região. Isso permitirá desenvolver séries históricas sintéticas de longo prazo com a metodologia de mesoescala, ajudando no conhecimento da climatologia local e reduzindo as incertezas dos projetos eólicos.

Resumo Palavras-chave: Aerogerador. Esteira turbulenta. Modelos em escala reduzida. AbstractThe interaction between the incident wind and wind turbines in a wind farm causes mean velocity deficit and increased levels of turbulence in the wake. The turbulent flow is characterized by the superposition of the wind turbine wakes. In this work, the technique of turbulence spectral evaluation to reduce scale models in a boundary layer wind tunnel is presented, and different measurements of velocity fluctuations are analyzed. The results allow evaluating the spectrum configuration at different frequency ranges and the differences of the spectral behavior between the incident wind and the turbine wake flow.