Computational Fluid Dynamics


Also found in: Dictionary, Acronyms, Wikipedia.

Computational fluid dynamics

The numerical approximation to the solution of mathematical models of fluid flow and heat transfer. Computational fluid dynamics is one of the tools (in addition to experimental and theoretical methods) available to solve fluid-dynamic problems. With the advent of modern computers, computational fluid dynamics evolved from potential-flow and boundary-layer methods and is now used in many diverse fields, including engineering, physics, chemistry, meteorology, and geology. The crucial elements of computational fluid dynamics are discretization, grid generation and coordinate transformation, solution of the coupled algebraic equations, turbulence modeling, and visualization.

Numerical solution of partial differential equations requires representing the continuous nature of the equations in a discrete form. Discretization of the equations consists of a process where the domain is subdivided into cells or elements (that is, grid generation) and the equations are expressed in discrete form at each point in the grid by using finite difference, finite volume, or finite element methods. The finite difference method requires a structured grid arrangement (that is, an organized set of points formed by the intersections of the lines of a boundary-conforming curvilinear coordinate system), while the finite element and finite volume methods are more flexible and can be formulated to use both structured and unstructured grids (that is, a collection of triangular elements or a random distribution of points).

There are a variety of approaches for resolving the phenomena of fluid turbulence. The Reynolds-averaged Navier-Stokes (RANS) equations are derived by decomposing the velocity into mean and fluctuating components. An alternative is large-eddy simulation, which solves the Navier-Stokes equations in conjunction with a subgrid turbulence model. The most direct approach to solving turbulent flows is direct numerical simulation, which solves the Navier-Stokes equations on a mesh that is fine enough to resolve all length scales in the turbulent flow. Unfortunately, direct numerical simulation is limited to simple geometries and low-Reynolds-number flows because of the limited capacity of even the most sophisticated supercomputers. See Turbulent flow

The final step is to visualize the results of the simulation. Powerful graphics workstations and visualization software permit generation of velocity vectors, pressure and velocity contours, streamline generation, calculation of secondary quantities (such as vorticity), and animation of unsteady calculations. Despite the sophisticated hardware, visualization of three-dimensional and unsteady flows is still particularly difficult. Moreover, many advanced visualization techniques tend to be qualitative, and the most valuable visualization often consists of simple x-y plots comparing the numerical solution to theory or experimental data.

Computational fluid dynamics has wide applicability in such areas as aerodynamics, hydraulics, environmental fluid dynamics, and atmospheric and oceanic dynamics, with length and time scales of the physical processes ranging from millimeters and seconds to kilometers and years. Vehicle aerodynamics and hydrodynamics, which have provided much of the impetus in the development of computational fluid dynamics, are primarily concerned with the flow around aircraft, automobiles, and ships. See Aerodynamic force, Aerodynamics, Fluid flow, Hydrodynamics

computational fluid dynamics

[‚käm·pyə′tā·shən·əl ′flü·əd dī′nam·iks]
(fluid mechanics)
A field of study concerned with the use of high-speed digital computers to numerically solve the complete nonlinear partial differential equations governing viscous fluid flows.

Computational fluid dynamics

The numerical approximation to the solution of mathematical models of fluid flow and heat transfer. Computational fluid dynamics is one of the tools (in addition to experimental and theoretical methods) available to solve fluid-dynamic problems. With the advent of modern computers, computational fluid dynamics evolved from potential-flow and boundary-layer methods and is now used in many diverse fields, including engineering, physics, chemistry, meteorology, and geology. The crucial elements of computational fluid dynamics are discretization, grid generation and coordinate transformation, solution of the coupled algebraic equations, turbulence modeling, and visualization.

Numerical solution of partial differential equations requires representing the continuous nature of the equations in a discrete form. Discretization of the equations consists of a process where the domain is subdivided into cells or elements (that is, grid generation) and the equations are expressed in discrete form at each point in the grid by using finite difference, finite volume, or finite element methods. The finite difference method requires a structured grid arrangement (that is, an organized set of points formed by the intersections of the lines of a boundary-conforming curvilinear coordinate system), while the finite element and finite volume methods are more flexible and can be formulated to use both structured and unstructured grids (that is, a collection of triangular elements or a random distribution of points). See Finite element method

There are a variety of approaches for resolving the phenomena of fluid turbulence. The Reynolds-averaged Navier-Stokes (RANS) equations are derived by decomposing the velocity into mean and fluctuating components. An alternative is large-eddy simulation, which solves the Navier-Stokes equations in conjunction with a subgrid turbulence model. The most direct approach to solving turbulent flows is direct numerical simulation, which solves the Navier-Stokes equations on a mesh that is fine enough to resolve all length scales in the turbulent flow. Unfortunately, direct numerical simulation is limited to simple geometries and low-Reynolds-number flows because of the limited capacity of even the most sophisticated supercomputers.

The final step is to visualize the results of the simulation. Powerful graphics workstations and visualization software permit generation of velocity vectors, pressure and velocity contours, streamline generation, calculation of secondary quantities (such as vorticity), and animation of unsteady calculations. Despite the sophisticated hardware, visualization of three-dimensional and unsteady flows is still particularly difficult. Moreover, many advanced visualization techniques tend to be qualitative, and the most valuable visualization often consists of simple x-y plots comparing the numerical solution to theory or experimental data. See Computer graphics

Computational fluid dynamics has wide applicability in such areas as aerodynamics, hydraulics, environmental fluid dynamics, and atmospheric and oceanic dynamics, with length and time scales of the physical processes ranging from millimeters and seconds to kilometers and years. Vehicle aerodynamics and hydrodynamics, which have provided much of the impetus in the development of computational fluid dynamics, are primarily concerned with the flow around aircraft, automobiles, and ships. See Aerodynamic force, Aerodynamics, Hydraulics, Simulation

Computational Fluid Dynamics

(language)
(CFD) A Fortran-based parallel language for the Illiac IV.
References in periodicals archive ?
In the case of computational fluid dynamics, researchers have greatly improved their simulations in the last few years to achieve reliable results.
The report, Computational Fluid Dynamics Software Market in the Asia Pacific 2010-2014, is based on extensive research conducted with industry experts, vendors, and end-users.
This report by TechNavio Insights highlights the scope of the Global Computational Fluid Dynamics market over the period 2009-2013.
Modern day practitioners employ computational fluid dynamics in both determining likely causes of fires and developing new structure designs in an attempt to prevent similar future occurrences.
Dale Snider is a mechanical engineer specializing in computational fluid dynamics.
Dassault Systemes (DS) (Nasdaq: DASTY) (Paris: DSY), a world leader in 3D and Product Lifecycle Management (PLM) solutions, announces the availability of a powerful coupled-analysis capability for fluid-structure interaction (FSI) utilizing ABAQUS, the technology-leading finite element analysis (FEA) software from their SIMULIA brand, and STAR-CD, a market-leading computational fluid dynamics (CFD) software from CD-adapco.
The objective of this program is to provide a capability to perform special focused studies in the area of air vehicle advanced aero configurations, aero configuration integration, high-speed aerodynamics, aero-thermodynamics, controls theory, flight vehicle performance, flow diagnostics, flying qualities, stability and control, computational fluid dynamics and computational electromagnetic research, airframe-propulsion-stores (weapons) integration, aerospace vehicle demonstration and general technical support.
Fond du Lac, Wisconsin, has made dramatic strides in its ability to understand the lost foam casting process using computational fluid dynamics (CFD) software that allows engineers to model metal flow in the mold on the computer screen.
0 computational fluid dynamics (CFD) software running on the upcoming 64-bit Microsoft Windows operating system on a four-way AMD Opteron processor-based server.
ALGOR software also provides full compatibility with industry-standard NASTRAN input and output files so that NASTRAN and/or FEMAP[R](a) users can benefit from ALGOR's value-added capabilities including structured and unstructured hex-dominant solid meshing and complementary analysis tools such as computational fluid dynamics (CFD) and MES for nonlinear, multi-body dynamics with large-scale motion, large deformation and large strain with body-to-body contact, which allows engineers to see motion and its results, such as impact, buckling and permanent deformation.
The ERDC MSRC specializes in five DoD-designated computational technology areas, including computational structural mechanics, computational fluid dynamics, climate/weather/ocean modeling and simulation, forces modeling and simulation and environmental quality modeling and simulation.
extraction dynamics analysis and computational fluid dynamics analysis); University of Arizona of Tucson, Ariz.

Full browser ?