Exp 2 Flow Visualization 2014
MEHB221
Fluids Mechanics Lab
2014
Experiment No. 2
FLOW VISUALIZATION
Objectives
To study the flow lines and path lines in fluids mechanics (steady flow), and investigate the influence of different shaped bodies on the flow.
Apparatus
Flow Visualization Unit, FM 22 (Figure 4).
Hydraulic Bench, FM 110.
Summary of Theory
Timelines, Pathlines, Streaklines and Streamlines (Flow lines)
In the analysis of problems in fluid mechanics, frequently it is advantageous to obtain a visual representation of a flow field. Such a representation is provided by timelines, pathlines, streaklines, and streamlines (flow lines). If a number of adjacent fluid particles in a flow field are marked at a given instant, they form a line in the fluid at that instant; this line is called a timeline.
A pathline is the path or trajectory traced out by a moving fluid particle. To make a pathline visible, we might identify a fluid particle at a given instant, e.g., by the use of dye, and then take a long exposure photograph of its subsequent motion. The line traced out by the particle is a pathline.
On the other hand, we might choose to focus our attention on a fixed location in space and identify, again by the use of dye, all fluid particles passing through this point. After a short period of time we would have a number of identifiable fluid particles in the flow, all of which had, at some time, passed through one fixed location in space. The line joining these fluid particles is defined as a streakline.
Streamlines (flow lines) are lines drawn in the flow field so that at a given instant they are tangent to the direction of flow at every point in the flow field. Since the streamlines are tangent to the velocity vector at every point in the flow field, there can be no flow across a streamline. In steady flow, the velocity at each point in the flow field remains constant with time and, consequently, the streamlines do not vary from one instant to the next. This implies that a particle located
Fluids Mechanics Lab
2014
Experiment No. 2
FLOW VISUALIZATION
Objectives
To study the flow lines and path lines in fluids mechanics (steady flow), and investigate the influence of different shaped bodies on the flow.
Apparatus
Flow Visualization Unit, FM 22 (Figure 4).
Hydraulic Bench, FM 110.
Summary of Theory
Timelines, Pathlines, Streaklines and Streamlines (Flow lines)
In the analysis of problems in fluid mechanics, frequently it is advantageous to obtain a visual representation of a flow field. Such a representation is provided by timelines, pathlines, streaklines, and streamlines (flow lines). If a number of adjacent fluid particles in a flow field are marked at a given instant, they form a line in the fluid at that instant; this line is called a timeline.
A pathline is the path or trajectory traced out by a moving fluid particle. To make a pathline visible, we might identify a fluid particle at a given instant, e.g., by the use of dye, and then take a long exposure photograph of its subsequent motion. The line traced out by the particle is a pathline.
On the other hand, we might choose to focus our attention on a fixed location in space and identify, again by the use of dye, all fluid particles passing through this point. After a short period of time we would have a number of identifiable fluid particles in the flow, all of which had, at some time, passed through one fixed location in space. The line joining these fluid particles is defined as a streakline.
Streamlines (flow lines) are lines drawn in the flow field so that at a given instant they are tangent to the direction of flow at every point in the flow field. Since the streamlines are tangent to the velocity vector at every point in the flow field, there can be no flow across a streamline. In steady flow, the velocity at each point in the flow field remains constant with time and, consequently, the streamlines do not vary from one instant to the next. This implies that a particle located