Chapter 20, Problem 18A

(a)

To determine

To define: The term streamlines

Explanation of Solution

Introduction:

Streamlines is defined as the smooth path that is followed by a fluid without any turbulence. Streamline flow can also be considered as the flow of lamina.

Streamlines are the family of curves that are tangential to instant velocity direction at every point. Streamline concept is very useful in explaining the flow field in terms of speed as well as its direction. In a steady flow, the fluid will be in motion but the streamlines will remain fixed.

(b)

To determine

To identify: Whether the pressure will be greater or lesser in region of crowded streamlines.

Answer to Problem 18A

The pressure will be lesser in regions where the streamlines are crowded.

Explanation of Solution

Introduction:

Streamlines are the family of curves that are tangential to instant velocity direction at every point. Streamline concept is very useful in explaining the flow field in terms of speed as well as its direction.

The place where streamlines are crowded will have lesser pressure because the fluid speed will be comparatively high. Also, the pressure will be less when streamlines flow through a narrow region.

Conclusion:

Therefore, pressure will be lesser.