Flow through ducts with sudden (sharp-edged) contractions occurs in many industrial applications. The flow separation
What is the head loss for flow with sudden enlargement and sudden contraction?
Loss of head due to sudden enlargement: This is the energy loss due to sudden enlargement. Sudden enlargement in the diameter of pipe results in the formation of
eddies
in the flow at the corners of the enlarged pipe (Fig. 1). This results in the loss of head across the fitting.
What is sudden contraction in pipe?
An abrupt contraction is
geometrically the reverse of an abrupt enlargement
(Fig. 14.3). Here also the streamlines cannot follow the abrupt change of geometry and hence gradually converge from an upstream section of the larger tube.
Does pressure increase with contraction?
The flow of fluid through a contraction (decrease in pipe diameter) results in
an increase in the velocity
and consequently, a pressure drop greater than the value for the equivalent straight pipe.
What is sudden contraction?
Introduction. The sudden contraction in the area/diameter of a fluid jet after it emerges from a circular aperture in a pressurized reservoir is called as
vena contracta
. Coefficient of contraction is the ratio of the cross sectional area of the jet at the vena contracta to the area of the orifice.
What is the correct formula for loss at the sudden contraction of a pipe?
The head loss due to pipe fittings is given by the following equation:
K
L
= Friction loss co-efficient/ loss co
-efficient, depend on the shape, size and type of pipe fittings. Q 1. The velocity of water flowing through a 12 cm diameter pipe was found to be 3.5 m/s.
When flowing fluid is incorrect minor energy losses in a pipe occurs due to?
Minor Losses: These occur due to
various fittings, valves, bends, elbows, tees, inlets, exits, contractions, and expansions
.
What are the different causes of loss of energy in pipe flow?
Major losses are associated with frictional energy loss that is caused by the
viscous effects of the medium and roughness of the pipe wall
. Minor losses, on the other hand, are due to pipe fittings, changes in the flow direction, and changes in the flow area.
Which type of flow is controlled by Reynolds number?
laminar flow
occurs at low Reynolds numbers, where viscous forces are dominant, and is characterized by smooth, constant fluid motion; turbulent flow occurs at high Reynolds numbers and is dominated by inertial forces, which tend to produce chaotic eddies, vortices and other flow instabilities.
Which blood vessels handle the highest blood pressure?
Blood pressure tends to be the greatest near the heart, and decreases as blood flows to the capillaries. The pressure is greatest at
the aorta
and gradually decreases as blood moves from the aorta to large arteries, smaller arteries, and capillaries.
Why pressure changes are not the best way to control blood flow?
Explain why pressure changes are not the best way to control blood flow. Your answer: because
pressure changes do not affect the flow rate as well as vessel radius or viscosity
. The changes in blood flow though pressure is not as significant. Use your data to calculate the increase in flow rate in ml/min/mm Hg.
What is the relationship between cardiac muscle stretch and the force of contraction?
This principle states that, within physiological limits, the force of heart contraction is
directly proportional to the initial length of the muscle fiber
. This means that the greater the stretch of the ventricular muscle (within limits), the more powerful the contraction is, which in turn increases SV.
How do you find the coefficient of contraction?
The coefficient of contraction is defined as the ratio between the area of the jet at the vena contracta and the area of the orifice.
C
c
= Area at vena contracta/Area of orifice
. The typical value may be taken as 0.611 for a sharp orifice (concentric with the flow channel).
Which one of the following is a major loss?
1. Which one of the following is a major loss? Explanation: The major
loss for the flflow through the pipes
is due to the frictional resistance between adjacent fluid layers sliding over each other. All other losses are considered to be minor losses.
What is contraction coefficient?
Coefficient of contraction is defined as
the proportion between the areas of the stream at the vena contracta to the area of the orifice
. It is denoted by the symbol C
c
. … Here, cross-sectional area of the jet is A
J
and the cross-sectional area of orifice is A
o
.
