Computational Fluid Dynamics Computational fluid dynamics (CFD) is the simulation of fluids in engineering systems using modeling such as mathematical physical problem formulation and numerical methods like discretization methods, solver, numerical parameters and grid generation. Computational fluid dynamics is based on the concept of Reynolds averaging of the unsteady Navier-Stokes equation commonly known as (RANS) which are considered by Leishman to be the most adaptable method for analyzing nonlinear viscous flows providing that a suitable turbulence model is employed. In VAWT, this nonlinearity is enhanced by the presence of the dynamic stall phenomenon due to the rapid change in the angle of attack of the blades during turbine
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As it is a new method it has many advantages over experimental method. The CFD method is cost effective and simulation can be done for any scale. The time process is short when compared to experimental method and on safety basis CFD is preferred. CFD is mainly used in industries like aerospace, chemical processing, automotive, biomedicine, heat ventilation air condition, power generation etc; to reduce the costs [9].
Governing Equation
The cornerstone of computational fluid dynamics is the fundamental governing equations of fluid dynamics — the continuity, momentum and energy equations. They are the mathematical statements of three fundamental physical principles upon which all of fluid dynamics is based: Mass is conserved F = ma (Newton’s second law of motion) Energy is …show more content…
CFD is, in part the art of replacing the governing partial differential equations of fluid flow with numbers and advancing these numbers in space and/or time to obtain a final numerical description of the complete flow field of interest and translate into discretized form. CFD solutions generally require the repetitive manipulation of thousands, or even millions of numbers, a task than is humanly impossible without the support of a computer [12]. These translators are numerical discretization methods like Finite difference, Finite volume methods and Finite element. Actually we have to break down our problem into small parts because the discretization is based on them. Then programs are written to solve, generally they written in typical languages like Fortran and C. The programs are run on workstation or supercomputers. Finally we get the simulation results which we can compare and analyze with experiments and real problems. If the results are not convincing to solve the problem we can repeat the simulation until we get a satisfying results. This is the CFD process [9]. The Fluid has important properties like density, viscosity, pressure, temperature and velocity. Density is defined as mass per unit volume. If the density of the fluid is constant or there is only a small change, it is called as incompressible
As it is a new method it has many advantages over experimental method. The CFD method is cost effective and simulation can be done for any scale. The time process is short when compared to experimental method and on safety basis CFD is preferred. CFD is mainly used in industries like aerospace, chemical processing, automotive, biomedicine, heat ventilation air condition, power generation etc; to reduce the costs [9].
Governing Equation
The cornerstone of computational fluid dynamics is the fundamental governing equations of fluid dynamics — the continuity, momentum and energy equations. They are the mathematical statements of three fundamental physical principles upon which all of fluid dynamics is based: Mass is conserved F = ma (Newton’s second law of motion) Energy is …show more content…
CFD is, in part the art of replacing the governing partial differential equations of fluid flow with numbers and advancing these numbers in space and/or time to obtain a final numerical description of the complete flow field of interest and translate into discretized form. CFD solutions generally require the repetitive manipulation of thousands, or even millions of numbers, a task than is humanly impossible without the support of a computer [12]. These translators are numerical discretization methods like Finite difference, Finite volume methods and Finite element. Actually we have to break down our problem into small parts because the discretization is based on them. Then programs are written to solve, generally they written in typical languages like Fortran and C. The programs are run on workstation or supercomputers. Finally we get the simulation results which we can compare and analyze with experiments and real problems. If the results are not convincing to solve the problem we can repeat the simulation until we get a satisfying results. This is the CFD process [9]. The Fluid has important properties like density, viscosity, pressure, temperature and velocity. Density is defined as mass per unit volume. If the density of the fluid is constant or there is only a small change, it is called as incompressible