Fluid Dynamic Flashcards
What is a control volume?
A specified region in fluid space where fluid properties and flow are analyzed.
Characteristics of an ideal fluid
Zero viscosity, incompressible, no surface tension, does not change phase.
Definition of steady flow
A condition where fluid properties at any point do not change over time.
Definition of uniform flow
A condition where fluid properties are constant across any section at any instant.
What is 1-D flow and its practical relevance?
An assumption that fluid properties are uniform over a plane; simplifies analysis.
What is volume flow rate?
The volume of fluid passing through a section per unit time.
What is a streamline in fluid dynamics?
An imaginary line in fluid flow that aligns with the velocity vector of the flow.
Characteristic of streamlines in uniform flow
They are straight and parallel.
What is a streakline?
A line joining all fluid particles that have passed through a particular point.
Difference between pathline and streamline
Pathline traces a single fluid particle’s route; streamline shows flow direction at an instant.
What happens to streamlines, streaklines, and pathlines in steady flow?
They all coincide, representing the same trajectory.
Why do we use the concept of control volume?
To analyze the changes and transfers across a boundary in a fluid system.
How does viscosity affect an ideal fluid?
An ideal fluid has zero viscosity; real fluids with viscosity resist flow.
What does it mean if a fluid is incompressible?
Its volume and density remain constant under pressure changes.
When is flow considered steady?
When there are no changes in fluid properties, mass, heat, and work transfer rates over time.
