Basic concepts of fluid flow-fluid kinematics and dynamics
- 1. Unit – 2 – Basic Concepts of Fluid flow • Kinematics: Classification of flows – Streamline, streak-line and path- lines – Stream function and velocity potentials – Flow nets • Dynamics : Application of control volume to continuity, energy and momentum – Euler’s equation of motion along a stream line – Bernoulli’s equation – Applications to velocity and discharge measurements – Linear momentum equation – Application to Pipe bends – Moment of momentum equation.
- 26. • Velocity potential function and stream function are two scalar functions that help study whether the given fluid flow is rotational or irrotational. • Both the functions provide a specific Laplace equation. The fluid flow can be rotational or irrotational flow based on whether it satisfies the Laplace equation or not. • Velocity potential function: defined as a scalar function of space and time such that its negative derivative with respect to any direction gives the fluid velocity in that direction. • Stream function: scalar function of space and time such that its partial derivative with respect to any direction gives velocity component at right angles to that direction
- 28. Flow nets
- 31. Methods of drawing flow nets •Analytical method – equations •Graphical method – graphs •Electrical analogy method – flow of fluid is analogous to flow of current. •Uses -ideal flow pattern – identify -all irrotational flow with similar geometry Spacing between adjacent streamlines can be determined; determine the efficient boundary shapes;