Continuity equation - ducts and nozzles, Other Engineering

Continuity equation

If we consider the machine to be an open-ended duct, we find that the mass flow per second will depend on the density of the fluid and the volume flowing per sec:

644_ducts nozzals.png

Now volume flow = Area of duct x distance travelled (L)/ Time (sec)
But the distance travelled per second = Velocity.
Therefore, Mass flow = density x area x velocity.
This is known as the ‘continuity equation' and it is true for any steady flow system regardless of changes in the cross-sectional area of the duct.

INCOMPRESSIBLE FLUID FLOW.

Now consider an incompressible fluid as it flows through the duct system shown in the fig. 1.7. We know that the mass flow is of a constant value and, naturally, as the fluid enters the larger cross sectional area it will take up the new shape and the initial volume will now occupy less length in the duct. Therefore, in a given time, less distance is travelled and the velocity is reduced.
Thus we conclude that if the mass flow is to remain constant, as it must, an increase in duct area must be accompanied by a reduction in flow velocity, and a decrease in duct area must bring about an increase in velocity; we can express this action as - velocity varies inversely with changes

369_ducts.png

Posted Date: 9/11/2012 7:04:46 AM | Location : United States







Related Discussions:- Continuity equation - ducts and nozzles, Assignment Help, Ask Question on Continuity equation - ducts and nozzles, Get Answer, Expert's Help, Continuity equation - ducts and nozzles Discussions

Write discussion on Continuity equation - ducts and nozzles
Your posts are moderated
Related Questions

Permeability of Moulding Sand  is the property of the sand, which permits the gases and steam to escape through the sand mould. For this purpose, the sand must be porous. Permeabil

what is the basics suggetion for the education values

DEPLETION MODE MOSFET: In the depletion-mode type, charge carriers are present in the channel at "Zero" gate bias and the device is, therefore, conducting.  The application of


Expertsmind.com brings you unique solution in electrical engineering -          A constellation is a region of the sky with well defined borders; familiar star pat

Sprinkler system - fire protection engineering Sprinkler systems may be installed in a building to achieve a number of different objectives.  Very often the primary reason for

Two types of climb will be considered. The first is the so-called steady climb. This is a climb in which the all acceleration components (i.e. parallel and perpendicular to the fli

How do comets get their tails? - Most comets stay frozen in the outer solar system. Only a few enter the inner solar system where they can grow tails. - When a comet nears the sun

Specify the inner-loop gain such that the damping coefficient of the closed loop is equal to 0.4