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The present work focuses on the numerical investigation of fluid flow due to dam-break with a simplified building model. OpenFOAM®, an open source computational fluid dynamics tool was used to run the three-dimensional dam-break simulation. The volume of fluid (VOF) method was used to track the free surface or phase fraction(α) between two fluid interface. The results from the simulation are post-processed using Paraview. Liquid phase evolution at various time steps and flood wave impact on the different zones in the domain are discussed. In the downstream region, a low pressure wake zone was identified in the vicinity of the building. To escape from the dam-break flooding, the safer regions are identified through the simulation results. [ABSTRACT FROM AUTHOR]

The competency, simplicity, and robustness of the open-source code written in C++ language; OpenFOAM® has gained the researcher's attention to explore and contribute to the same for producing quality outcomes. The availability of several steady and unsteady solvers working on different algorithms calls for the correct selection among them for simulating the test case. The present work focuses to simulate the two-dimensional compressible axisymmetric jet issuing out of a circular nozzle using three transient solvers available in OpenFoam® version 7; rhoCentralFoam, rhoPimpleFoam, and SonicFoam. The time-averaged values of pressure, velocity, temperature, and density were plotted over the centreline of the axisymmetric domain and a comparison was drawn to assess the capability of each solver to predict the outcomes as close to the experimental data. The advantages and disadvantages of these solvers will be inferred and the best among them will be selected for capturing extensive flow details of the compressible jet. [ABSTRACT FROM AUTHOR]

The most widely investigated model for the study of flow separation is the Backward Facing Step (BFS). The separation phenomenon can be found in several aerodynamic and heat transfer systems. The sudden decrement in the pressure gradient due to expansion of the flow leads to the separation of the shear layer at the step edge resulting in the formation of a separation bubble. The extent of the recirculation region is devised from the measurement of the re-attachment length. These measures are dependent on the flow and geometric properties. The chaotic interactions of the vortices shredded from the step edge and the upper wall surface open a wide domain to explore and study its characteristics. Several researchers in the past have theoretically, experimentally, and computationally obtained outcomes to study these kinds of flows. The present study was performed to investigate the complex interactions between the vortices formed at the step edge, the upper wall, and the secondary vortices forming in the secondary re-circulation region. The simulation was performed using an open-source CFD software package; OpenFOAM® using a transient incompressible solver which incorporates the PISO (Pressure Implicit with Splitting of operators) algorithm to solve the pressure-velocity linked equations. The visualisation outcomes at the uniform time interval of 0.001 seconds were presented along with several energy modes identified using the mathematical technique of POD (Proper Orthogonal Decomposition) were also presented in this script. [ABSTRACT FROM AUTHOR]