# Fluid Dynamics Topics

Acoustic Streaming
Unidirectional flow currents in a fluid that are due to the presence of sound waves.
Aerodynamic Drag
Resistance of a vehicle body to motion through the air. A smooth surface has less drag than a rough one.
Atmospheric Boundary Layer
The atmospheric layer adjacent to the surface of the Earth that is affected by friction against the surface boundary.
Back Pressure
Pressure exerted backward; in a field of fluid flow, a pressure exerted contrary to the pressure producing the main flow.
Bernoulli′s Principle
The pressure in a fluid decreases as its velocity increases.
Boost Pressure
The increase above atmospheric pressure produced inside the intake manifold by a forced-induction system such as a turbocharger or supercharger.
Boundary Layer
The portion of a fluid flowing past a body that is in the immediate vicinity of the body.
Brookfield Viscosity
Apparent viscosity determined by Brookfield viscometer.
Centre of Pressure
The point at which the aerodynamic forces on a body appear to act, and at which there is no aerodynamic movement.
Clogging
The restriction of a flow path due to the accumulation of material along the flow path boundaries.
Computational Fluid Dynamics
A tool for predicting the aerodynamics and fluid dynamics of air around flight vehicles by solving a set of mathematical equations with a computer.
Condensation Shock Wave
A sheet of discontinuity associated with a sudden condensation and fog formation in a field of flow.
darcy
A CGS unit of permeability.
Differential Pressure Indicator
An indicator which signals the difference in pressure between two points, typically between the upstream and downstream sides of a filter, valve or expansion element.
Drag
Resistance of a vehicle body to motion through the air. A smooth surface has less drag than a rough one.
Drag Coefficient
A dimensionless value that allows the comparison of shape and orientation of different bodies.
Dribbling
Slow seeping of liquid from a control valve after it has been closed.
Dynamic Pressure
The pressure of a fluid resulting from its motion when brought to rest on a surface.
Dynamic viscosity
That molecular property of a fluid which enables it to support tangential stresses for a finite time and thus to resist deformation.
Fluid Dynamics Books
Lists all Fluid Dynamics Books in the Encyclopaedia
Fluid Dynamics Calculations
Lists all Fluid Dynamics Calculations in the Encyclopaedia
Fluid Dynamics Conversions
Lists all Fluid Dynamics Conversions in the Encyclopaedia
Lists all Fluid Dynamics Weblinks in the Encyclopaedia
Fluid Pump
A device for moving fluids.
Hydrostatic Pressure
The pressure at any point in a liquid at rest; equal to the depth of the liquid multiplied by its density.
Impact Pressure
Another name for Dynamic Pressure.
Inertial Impaction
The process whereby a particle moving in a gas stream strikes slowly moving or stationary obstacles or targets directly in its path.
Inviscid
Not viscous, not clinging or sticky, frictionless.
Inviscid Fluid
A perfect fluid.
Kinematic Viscosity
The dynamic viscosity of a fluid divided by the fluid density.
Mass Median Particle Diameter
The particle diameter at which half the particulate mass is composed of particles larger than this diameter and half the mass is composed of particles smaller than this diameter.
Molecular Slip
The existence of a finite net gas velocity at the surface of very small particles resulting in a lower drag force.
Navier Stokes Codes
Computer software that contains the mathematical equations of motion for a viscous fluid.
Negative Pressure
A relative pressure that is below atmospheric pressure.
Pascal Second
The SI unit of dynamic viscosity, equal to 10 poise.
Perfect Fluid
A fluid chiefly characterized by lack of viscosity and, usually, by incompressibility.
Pressure
Defined as the force exerted per unit area.
Pressure Coefficient
A dimensionless value which acts as a means of indicating the local pressure at some point of interest around a body, and which is independent of velocity.
Pressure Drop
A measure of the resistance the gas stream encounters as it flows through an air control device or other piece of equipment.
Pressure head is one of the main characteristics of a pump.
Pressure Relief Valve
A type of valve used to control or limit the pressure in a system or vessel.
Pressure Zone
As sound waves strike a solid surface, the particle velocity is zero at the surface and the pressure is high, thus creating a high-pressure layer near the surface.
Profile Drag
This is drag from the three-dimensional shape of the aircraft or vehicle.
Reynolds Stresses
The transfer of momentum due to turbulent fluctuations of a viscous, incompressible, homogeneous fluid in turbulent motion.
Richardson Number
A nondimensional number arising in the study of shearing flows of a stratified fluid.
Saybolt Universal Seconds
Another name for Saybolt Universal Viscosity.
Saybolt Universal Viscosity
The time in seconds required for 60 cubic centimeters of a fluid to flow through the orifice of the Standard Saybolt Universal Viscometer at a given temperature under specified conditions.
Service Drag
This is drag from air ducted to cooling components.
Stagnation Pressure
Another name for Dynamic Pressure.
Static Pressure
A measure of the resistance of airflow through a system.
Supercritical Fluid
A fluid state that occurs when the pressure and temperature exceed the substance′s critical pressure and critical temperature.
Total Pressure
Another name for Dynamic Pressure.
Turbulence
Describes fluid motion disturbed from its average behaviour by random fluctuations over a range of temporal and spatial scales.
Turbulent Boundary Layer
Within this layer the Reynolds stresses are much larger than the viscous stresses.
Vehicle Aerodynamic Drag
Resistance of a vehicle body to motion through the air.
Velocity Pressure
The difference between dynamic pressure and static pressure.
Viscosity
A measure of the internal friction within a fluid.
Any of a number of systems which characterize lubricants according to viscosity for particular applications.
Viscosity Index
An arbitrary measure for the change of kinematic viscosity with temperature.
Viscosity Index Improvers
Additives that increase the viscosity of the fluid throughout its useful temperature range.
Viscosity Modifier
Lubricant additive, usually a high molecular weight polymer, that reduces the tendency of an oil′s viscosity to change with temperature.
Viscous
Possessing viscosity. Frequently used to imply high viscosity.
Viscous Flow
The flow of fluid through a duct under conditions such that the mean free path is very small in comparison with the smallest dimension of a transverse section of the duct.
Viscous Fluid
A fluid whose molecular viscosity is sufficiently large to make the viscous forces a significant part of the total force field in the fluid.
Viscous Force
The force per unit volume or per unit mass arising from the action of tangential stresses in a moving viscous fluid.
Weight Flow Rate
Mass flow rate multiplied by gravity.

Subjects: Mechanical Engineering Physics