Câu hỏi ôn tập môn Thủy lực 01 (CSU-HYD201)

• Đăng bởi: nguyenphuocbinh
• Sinh viên
• 18/07/2018

1 What is the difference between gage pressure and absolute pressure?

2 Explain why some people experience nose bleeding and some others experience shortness of breath at high elevations.

3  Someone claims that the absolute pressure in a liquid of constant density doubles when the depth is doubled. Do you agree? Explain.

4  A tiny steel cube is suspended in water by a string. If the lengths of the sides of the cube are very small, how would you compare the magnitudes of the pressures on the top, bottom, and side surfaces of the cube?

5  Express Pascal’s law, and give a real-world example of it.

6  Consider two identical fans, one at sea level and the other on top of a high mountain, running at identical speeds.

How would you compare (a) the volume flow rates and (b) the mass flow rates of these two fans?

7  A vacuum gage connected to a chamber reads 24 kPa at a location where the atmospheric pressure is 92 kPa. Determine the absolute pressure in the chamber.

8  A manometer is used to measure the air pressure in a tank. The fluid used has a specific gravity of 1.25, and the differential height between the two arms of the manometer is 28 in. If the local atmospheric pressure is 12.7 psia, determine the absolute pressure in the tank for the cases of the manometer arm with the (a) higher and (b) lower fluid level being attached to the tank.

9 Define mass and volume flow rates. How are they related to each other?

10  Does the amount of mass entering a control volume have to be equal to the amount of mass leaving during an unsteady-flow process?

 11 When is the flow through a control volume steady?

12 Consider a device with one inlet and one outlet. If the volume flow rates at the inlet and at the outlet are the same, is the flow through this device necessarily steady? Why?

13 What is mechanical energy? How does it differ from thermal energy? What are the forms of mechanical energy of a fluid stream?

14 What is mechanical efficiency? What does a mechanical efficiency of 100 percent mean for a hydraulic turbine?

15 How is the combined pump–motor efficiency of a pump and motor system defined? Can the combined pump motor efficiency be greater than either the pump or the motor efficiency?