Fluid Mechanics in SI Units 2nd. Edition by Russell Hibbeler | 9781292247304 | 1292247304

Fluid Mechanics

Fluid Mechanics in SI Units

164 SOLVED PROBLEMS

6 SOLVED PROBLEMS

Question: 13.14

A room is at atmospheric pressure, 101 kPa, and a temperature of 293 K. If the air from the room is drawn into a 100-mm-diameter pipe isentropically, such that it has an absolute pressure of p1 = 80 kPa as it enters the pipe, determine the mass flow and the stagnation temperature and stagnation ...

Verified Answer:

Fluid Description. We assume that adiabatic steady...

Question: 13.18

The nozzle in Fig. 13–39a is connected to a large reservoir where the absolute air pressure is 350 kPa. Determine the range of outside backpressures that cause a shock wave to form within the nozzle and just outside of it. ...

Verified Answer:

Fluid Description. We assume steady flow through t...

Question: 13.19

A jet plane is flying horizontally at 845 m/s, at an altitude where the air temperature is 10°C and the absolute pressure is 80 kPa. If an oblique shock forms on the nose of the plane, at the angle shown in Fig. 13–44a, determine the pressure and temperature, and the direction, of the air just ...

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Fluid Description. The air is considered compressi...

Question: 13.20

Air flows over a surface at a speed of 900 m/s, where the absolute pressure is 100 kPa and the temperature is 30°C. Expansion waves occur at the sharp transition shown in Fig. 13–47a. Determine the velocity, temperature, and pressure of the flow just to the right of the wave. ...

Verified Answer:

Fluid Description. We have steady compressible flo...

Question: 13.17

A jet plane is traveling at M = 1.5, where the absolute air pressure is 50 kPa and the temperature is 8°C. At this speed, a shock forms at the intake of the engine, as shown in Fig. 13–38a. Determine the pressure and velocity of the air just to the right of the shock. ...

Verified Answer:

Fluid Description. The control volume that contain...

Question: 13.16

The pipe in Fig. 13–37 transports air at a temperature of 20°C having an absolute pressure of 30 kPa and a speed of 550 m/s, measured just behind a standing shock wave. Determine the temperature, pressure, and speed of the air just in front of the wave. ...

Verified Answer:

Fluid Description. Shock wave formation is an adia...

Question: 13.15

Outside air is drawn isentropically into the pipe having a diameter of 200 mm, Fig. 13–34. When it arrives at section 1, it has a velocity of 75 m/s, an absolute pressure of 135 kPa, and a temperature of 295 K. If the walls of the pipe supply heat at 100 kJ/kg ⋅ m, determine the properties of the ...

Verified Answer:

Fluid Description. We assume the air to be invisci...

Question: 13.12

Air enters the 30-mm-diameter pipe with a velocity of 153 m/ s, and a temperature of 300 K, Fig. 13–28. If the average friction factor is f = 0.040, determine how long, Lmax, the pipe should be so that sonic flow occurs at the exit. Also, what is the velocity of the air in the pipe at the exit Lmax ...

Verified Answer:

Fluid Description. We assume that adiabatic steady...

Question: 13.11

Air flows through the 100-mm-diameter pipe in Fig. 13–23 having an absolute pressure of p1 = 90 kPa. Determine the diameter d at the end of the nozzle so that isentropic flow occurs out of the nozzle at M2 = 0.7. The air within the pipe is taken from a large reservoir at standard atmospheric ...

Verified Answer:

Fluid Description. We assume steady isentropic flo...

Question: 13.10

The Laval nozzle in Fig. 13–22 is connected to a large chamber containing air at an absolute pressure of 350 kPa. Determine the backpressure in the pipe at B that will cause the nozzle to choke and yet produce isentropic subsonic flow through the pipe. Also, what backpressure is needed to cause ...

Verified Answer:

Fluid Description. We assume steady isentropic flo...

Question: 14.10

A turbine for the dam operates under a hydraulic head of 90 m, producing a discharge of 50 m³/s. If the reservoir level drops so that the hydraulic head becomes 60 m, determine the discharge from the turbine. ...

Verified Answer:

Here

h_1

= 90 m and

Q_1[/lat...

Question: 3.4

As the valve in Fig. 3–17 is being gradually closed, oil particles flowing through the nozzle along the center streamline have a velocity of V = [6(1 + 0.4x²)(1 – 0.5t) ] m/s, where x is in meters and t is in seconds. Determine the acceleration of an oil particle when it arrives at x = 0.25 m when ...

Verified Answer:

Fluid Description. The flow along the streamline...

Question: 11.4

A small submarine has a triangular stabilizing fin on its stern with the dimensions shown in Fig. 11–15a. If the water temperature is 15°C, determine the drag on the fin when the submarine is traveling at 0.5 m/s. ...

Verified Answer:

Fluid Description. Relative to the submarine, th...

Question: 11.3

Air flows into the rectangular duct in Fig. 11–14a at 3 m/s. Determine the displacement thickness at the end of its 2-m length, and the uniform velocity of the core flow of air coming out of the duct. Take ρa = 1.20 kg/m³ and μa = 18.1(10^-6) N · s/m². ...

Verified Answer:

Fluid Description. We will assume the air is inc...

Question: 4.3

Air flows into the gas heater in Fig. 4–14 at a steady rate, such that at A its absolute pressure is 203 kPa, its temperature is 20°C, and its velocity is 15 m/s. When it exits at B, it has an absolute pressure of 150 kPa and a temperature of 75°C. Determine its velocity at B. ...

Verified Answer:

Fluid Description. As stated, we have steady flo...

Question: 1.3

Air contained in the tank, Fig. 1–8, is under an absolute pressure of 60 kPa and has a temperature of 60°C. Determine the mass of the air in the tank. ...

Verified Answer:

We will first find the density of the air in the t...