MEEN 345 EXAM 2 REVIEW QUESTIONS
Where is the location of the Vena Contracta for flow through an orifice? - Answers - The
point where the flow is narrowest.
What is the use of a pitot tube? - Answers - To measure the stagnation pressure.
You predicted the flow rate through an orifice using continuity and Bernoulli's equation.
The actual flow rate was less than the predicted flow rate. What is the most probable
cause? - Answers - The predicted result disregarded all frictional effects.
The volumetric flow rate, Q through the orifice is measured with the decreasing water
level, H in the tank. What is the relationship between the volumetric flow rate and the
pressure head in the tank? - Answers - Q is proportional to the sqrt of H.
What does the Vena Contracta in a fluid flow through an orifice represent? - Answers -
The point where the fluid stream reaches its minimum cross-sectional area and
maximum velocity.
A fluid passes through a sharp-edged orifice in the base of the tank. Two manometers
are installed: the manometer A connects to a Pitot tube which is positioned at the vena
contracta of the fluid stream, the other manometer B connects to a pressure tapping in
the base of the tank. Compare the heights of three water levels: manometer column A
and B, and water tank, C. What is the reason of different heads in manometers A and
B? - Answers - A < B = C
frictional head loss through the orifice
In the flow through an orifice experiment, three important coefficients are measured: the
discharge coefficient (CD), the velocity coefficient (CV), and the contraction coefficient
(CC). It is observed that the actual flow rate from the orifice is less than the theoretical
flow rate, the actual velocity at the Vena Contracta is less than the theoretical velocity,
and the cross-sectional area of the fluid stream at the Vena Contracta is smaller than
the cross-sectional area of the orifice. Which of the following sets of coefficient values
are likely to be true? - Answers - CD<1, CV<1, CC<1
The coefficient of pressure is a non-dimensional number to scale pressure
measurements from a model to a full sized item. What are some advantages of a non-
dimensional number? - Answers - It expresses the functional relationship between the
variables in dimensionless terms.
It reduces the number of variables involved in a physical phenomenon.
Where is the location of the Vena Contracta for flow through an orifice? - Answers - The
point where the flow is narrowest.
What is the use of a pitot tube? - Answers - To measure the stagnation pressure.
You predicted the flow rate through an orifice using continuity and Bernoulli's equation.
The actual flow rate was less than the predicted flow rate. What is the most probable
cause? - Answers - The predicted result disregarded all frictional effects.
The volumetric flow rate, Q through the orifice is measured with the decreasing water
level, H in the tank. What is the relationship between the volumetric flow rate and the
pressure head in the tank? - Answers - Q is proportional to the sqrt of H.
What does the Vena Contracta in a fluid flow through an orifice represent? - Answers -
The point where the fluid stream reaches its minimum cross-sectional area and
maximum velocity.
A fluid passes through a sharp-edged orifice in the base of the tank. Two manometers
are installed: the manometer A connects to a Pitot tube which is positioned at the vena
contracta of the fluid stream, the other manometer B connects to a pressure tapping in
the base of the tank. Compare the heights of three water levels: manometer column A
and B, and water tank, C. What is the reason of different heads in manometers A and
B? - Answers - A < B = C
frictional head loss through the orifice
In the flow through an orifice experiment, three important coefficients are measured: the
discharge coefficient (CD), the velocity coefficient (CV), and the contraction coefficient
(CC). It is observed that the actual flow rate from the orifice is less than the theoretical
flow rate, the actual velocity at the Vena Contracta is less than the theoretical velocity,
and the cross-sectional area of the fluid stream at the Vena Contracta is smaller than
the cross-sectional area of the orifice. Which of the following sets of coefficient values
are likely to be true? - Answers - CD<1, CV<1, CC<1
The coefficient of pressure is a non-dimensional number to scale pressure
measurements from a model to a full sized item. What are some advantages of a non-
dimensional number? - Answers - It expresses the functional relationship between the
variables in dimensionless terms.
It reduces the number of variables involved in a physical phenomenon.
