Turbulent Flow and Energy Conservation Concepts

A method of tracking fluid flow by focusing on individual fluid particles (like grains) as they move. The equations are written from the perspective of the moving particle.

Observes fluid flow at fixed points in space over time. The equations are written from the fixed reference frame of the space.

A set of fundamental equations that govern fluid mechanics problems.

An equation that expresses the conservation of mass within a control volume. Essentially, it states that the rate of change of mass within a system equals the mass flow into the system minus the mass flow out.

An equation describing the conservation of momentum in fluid flow. The momentum equation incorporates forces acting on the fluid, such as pressure gradients, body forces (gravity), and viscous stresses.

An equation describing the conservation of energy in fluid flow. It accounts for heat transfer, work done by pressure forces, viscous dissipation, and other sources of energy.

The Navier-Stokes Equations are a set of partial differential equations that describe the motion of viscous fluids.

A computational technique used to simulate and analyze fluid flow behavior.

The sum of all forces acting on a fluid element.

The rate of change of velocity of a fluid element.

The force per unit area exerted by a fluid on a surface.

The force that arises from the internal friction of a fluid.

The pressure gradient in a fluid.

The change of a fluid's velocity with respect to time.

The change of a fluid's velocity due to its motion in a non-uniform velocity field.

The force per unit volume exerted by a fluid.

The force that acts on the surface of a fluid element.

A type of fluid flow characterized by chaotic, unpredictable movement of fluid particles; it's common in natural phenomena like rivers and oceans, and in engineering situations like the airflow around cars.

The change in momentum of a fluid element over time; this relates to the forces acting on the fluid.

The transfer of heat through the movement of a fluid. Hot fluid rises, carrying energy with it.

External sources of energy that affect the fluid's behavior; these sources can be things like chemical reactions, radiation, or the addition of external heat.

The process of heat transfer from areas of high concentration to areas of low concentration; this is often driven by temperature gradients.

This describes the energy change within a fluid element as it moves; it accounts for the internal energy changes of the fluid.

The work done by pressure forces on a fluid; this is related to the volume changes and pressure gradients in the fluid.

A method simulating turbulent flows by directly solving for large-scale eddies, while approximating smaller ones with turbulence models - generally more accurate than RANS for unsteady flows.

A method simulating turbulent flows by using the Reynolds-averaged Navier-Stokes equations and turbulence models to represent small-scale eddies - computationally less demanding but less accurate for complex flows.

Breaking down a fluctuating velocity into a time-averaged component and a fluctuating component. The time average of the fluctuating component is zero.

Describes that in Reynolds Decomposition, the time-averaged value of the fluctuating component of velocity is always zero.

The square root of the time-averaged value of the square of a fluctuating component of velocity - a measure of the intensity of turbulence.

A set of equations used in the RANS approach to approximate the effects of turbulence by modeling the Reynolds stresses.

A type of simulation where the system's properties change over time.

A simulation that involves solving both flow and heat transfer equations simultaneously.

A simulation where the fluid flow solver is inactive, and only the heat transfer solver is active.

The initial conditions for a simulation, typically taken from a previous simulation.

A function that multiplies a variable's value by a specific factor.

Setting up the boundary conditions for the inlet of the simulation, specifying the temperature and flow conditions.

Using the results of a previous simulation as the starting point for a new simulation.

Making the solver ignore the fluid flow equations and only solve for the temperature.

Specifying the number of processors used for the simulation.

Specifying the frequency at which simulation results are saved.

The process of transferring data from a simulation to a different analysis, usually using a different type of software.

A type of simulation where the effects of fluid flow are applied to a structural model. This means the forces and heat generated by the fluid are considered when analyzing the structure.

A type of simulation where the fluid's behavior is calculated based on information from a previous structural analysis.

The condition applied to a component to limit its movement in a specified direction.

A specific type of boundary condition used to simulate the interaction between a fluid and a solid surface. This sets the pressure and temperature of the fluid at the contact zone.

A specific type of boundary condition used solely for pressure. The applied pressure is directly determined by the fluid flow calculations.

A specific type of boundary condition used solely for temperature. The temperature of the contact zone is directly defined.

This refers to the temperature of a component or system.

The force exerted by a fluid on a surface.

The process of running a simulation to test its correctness and obtain results.