Real-time wave forecasts are critical to a variety of coastal and offshore opera- tions. NOAA’s global wave forecasts, at present, do not extend into many coastal regions of interest. Even after more than two decades of the historical Exxon Valdez disaster, Cook Inlet (CI) and Prince William Sound (PWS) are regions that suffer from a lack of accurate wave forecast information. This dissertation develops high- resolution integrated wave forecasting schemes for these regions in order to meet the critical requirements associated with shipping, commercial and sport fishing vessel safety, and oil spill response. This dissertation also performs a detailed qualitative and quantitative assessment of the impact of various forcing functions on wave pre- dictions, and develops maps showing extreme variations in significant wave heights (SWHs). For instance, it is found that the SWH could vary by as much as 1 m in the northern CI region in the presence of currents (hence justifying the need for integration of the wave model with a circulation model). Such maps can be useful for several engineering operations, and could also serve as guidance tool as to what can be expected in certain regions. Aside from the system development, the issue of forecast reliability is also addressed for PWS region in the context of the associated uncertainty which confronts the manager of engineering operations or other planners. For this purpose, high-resolution 36-h daily forecasts of SWHs are compared with measurements from buoys and satellites for about a year. The results show that 70% of the peak SWHs in the range 5-8 m were predicted with an accuracy of 15% or less for a forecast lead time of 9 h. On average, results indicate 70% or greater likelihood of the prediction falling within a tolerance of ±(1*RMSE) for all lead times. This analysis could not be performed for CI due to lack of data sources.

In this thesis a 3-D Euler flow solver is coupled with a finite element program in order to solve static aeroelastic problems involving aircraft wings. A loosely coupled solution approach based on an iterative solution procedure is used to solve the coupled field problem. Because of the deformation of the underlying surface over which the flow is solved, Computational Fluid Dynamics mesh has to move at each computational aeroelastic iteration in order to comform to the new shape of the aerodynamic surface. As a part of this work, a procedure is developed in order to move fluid grid points, which views the whole computational domain as an isotropic elastic medium and solves it using finite element method. A matching discrete interface is defined / displacement and pressure data exchange is accomplished at this interface. AGARD Wing 445.6 and an elastic supercritical wing is modelled and solved with the developed computational aeroelastic procedure and the obtained results are compared with numerical and wind tunnel data.

[pt] O objetivo principal do trabalho consiste na análise de problemas de fluxo sob uma ótica integrada através de simulações numéricas. Tal perspectiva vêm ganhando grande atenção por parte de profissionais da área, pois permite uma abordagem mais representativa dos processos da natureza. O programa utilizado, Mike SHE, desenvolvido pelo Instituto de Hidráulica Dinamarquês, é criado num esquema determinístico e distribuído e utiliza o método das diferenças finitas como solução. O programa simula o fluxo na superfície, canais e nas zonas saturada e não saturada. No primeiro exemplo, simulou-se a interação entre um aquífero de baixa profundidade e um rio. No segundo, verificou-se a resposta do escoamento superficial submetido a variações metereológicas e fisiográficas. Ambos casos foram validados por soluções analíticas. No terceiro, realizou-se uma simulação integrada em uma escala regional para compreensão da resposta dinâmica entre os diversos armazenamentos e através de uma ferramenta de pós- processamento, calculou-se o balanço hídrico. Por fim, avaliou-se a resposta da bacia hidrográfica do Quitite e Papagaio, localizada no maciço da Tijuca, Rio de Janeiro, mediante registros de picos de precipitação anuais. As análises integradas foram satisfatórias comparando-se a modelagens individuais. O acoplamento é explícito, permitindo a inserção de passos de tempo convenientes com cada ambiente. Por fim, a abordagem integrada permitiu que os modelos dos quatro casos fossem calibrados de acordo com parâmetros de cada ambiente hidrogeológico, aumentando a confiabilidade das simulações. / [en] This master thesis aims the analysis of flow problems under an integrated approach through numerical flow modelling. The relevance of this perspective has been increasing steadily, since it allows a more representative assessment of the nature processes. The program used, named Mike SHE, developed by the Danish Hydraulic Institute, was created in a deterministic and distributed approach solved by finite difference method. The program is comprised of modules, each representing a storage: surface, channels, vadose and saturated zone. The first analysis comprise the interaction between an aquifer of low depth and a river. In the second example, it was verified the response of flow in a surface subjected to variation of physiografic and metereological parameters. Both examples were validated with analytical solutions. In the third case, an integrated simulation was carried on in order to understand the dynamic feedback generated between the storages and through a post-processing tool the water balance was calculated. The last example, assess the response the Quitite and Papagaio basin, located in the Tijuca s massif in the city of Rio de Janeiro, over high precipitation rate. The results were satisfactory in comparison of an individual flow analysis. The coupling is explicit, allowing the input of suitable time steps for each storage. Lastly, the integrated approach allowed the model setup in the four cases to be calibrated under parameters of each storage, enhancing the reliability of them.

In this thesis a fluid-structure coupling procedure which consists of a commercial flow solver, FLUENT, a finite element structural solver, MSC/NASTRAN, and the coupling interface between the two disciplines is developed in order to solve static and dynamic aeroelastic problems. The flow solver relies on inviscid Euler equations with finite volume discretization. In order to perform faster computations, multiple processors are parallelized. Closely coupled approach is used to solve the coupled field aeroelastic problems. For static aeroelastic analysis Euler equations and elastic linear structural equations are coupled to predict deformations under aerodynamic loads. Linear interpolation using Alternating Digital Tree data structure is performed in order to exchange the data between structural and aerodynamic grid. Likewise for dynamic aeroelastic analysis, a numerical method is developed to predict the aeroelastic response and flutter boundary. Modal approach is used for structural response and Newmark algorithm is used for time-marching. Infinite spline method is used to exchange displacement and pressure data between structural and aerodynamic grid. In order to adapt the new shape of the aerodynamic surface at each aeroelastic iteration, Computational Fluid Dynamic mesh is moved based on spring based smoothing and local remeshing method provided by FLUENT User Defined Function. AGARD Wing 445.6 and a generic slender missile are modeled and solved with the developed procedure and obtained results are compared with numerical and experimental data available in literature.

In this thesis, a loosely coupled Fluid-Structure Interaction (FSI) analysis method is developed for the solution of steady state missile/rocket aeroelastic problems. FLUENT is used as the Computational Fluid Dynamics (CFD) tool to solve Euler equations whereas ANSYS is used as the Computational Structural Dynamics (CSD) tool to solve linear structural problem. The use of two different solvers requires exchanging data between fluid and structure domains at each iteration step. Kriging interpolation method is employed for the data transfer between non-coincident fluid and structure grids. For mesh deformation FLUENT&rsquo / s built-in spring based smoothing approach is utilized. The study is mainly divided into two parts. In the first part static aeroelastic analysis for AGARD 445.6 wing is conducted and the results are compared with the reference studies. Deformation and pressure coefficient results are compared with reference both of which are in good agreement. In the second part, to investigate possible effects of aeroelasticity on rocket and missile configurations, static aeroelastic analysis for a canard controlled generic slender missile which is similar to a conventional 2.75&rdquo / rocket geometry is conducted and results of the analysis for elastic missile are compared with the rigid case. It is seen that the lift force produced by canards and tails lessen due to deformations, stability characteristics of the missile decreases significantly and center of pressure location changes due to the deformations in the control surfaces.