Fluid Flow Concepts and Basic Equations

Fluid Flow Concepts and Basic Equations
Definitions:

Descriptions of Fluid Motion
To describe fluid flow patterns and to identify important characteristics of the flow field, engineer must know the following:

Streamlines and Flow Patterns
• Flow patterns: it is the draw or pattern which imagine the flow field.
• The streamline: is a line drawn through the flow field in such a manner that the local velocity vector is tangent to the streamline at every point along the line at that instant.

Note: the tangent of the streamline at a given time gives the direction of the velocity vector.
the velocity of the fluid in the form, as shown in Fig. 12.2.

V= V(s, t)
Where:
s: is the distance traveled by a fluid particle along a path,
t: is the time.

Kinds of flow
Different types of flows can be:
Uniform flow:
It is the flow where the velocity does not change along a fluid path.
In uniform flow the fluid paths are straight and parallel as shown in Fig. 12.3 for flow in a pipe.

?V/( ?x)=0