Fluid Mechanics 2nd. Edition by Russell C. Hibbeler | 9780134649290 | 013464929X

Fluid Mechanics

8 SOLVED PROBLEMS

164 SOLVED PROBLEMS

Question: 13.4

Air at a temperature of 100°C is under pressure in the large tank shown in Fig. 13–9. If the nozzle is open, the air flows out at M = 0.6. Determine the temperature of the air at the exit. ...

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Fluid Description. The Mach number, M = 0.6 < 1...

Question: 5.4

A transition is placed in a rectangular air duct as shown in Fig. 5–14. If 2 kg/s of air flows steadily through the duct, determine the pressure change that occurs between the ends of the transition. Take ρa = 1.23 kg/m³. ...

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Fluid Description. We have steady flow. At slow ve...

Question: 5.1

A tornado has winds that essentially move along horizontal circular streamlines, Fig. 5–3. Within the eye, 0 ≤ r ≤ r0, the wind velocity is V = ωr, which represents a forced vortex, that is, flow rotating at a constant angular rate ω as described in Sec. 2.14. Determine the pressure distribution ...

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Fluid Description. We have steady flow, and we wil...

Question: 7.9

A tornado consists of a whirling mass of air such that the winds essentially move along horizontal circular streamlines, Fig. 7–29a. Determine the pressure distribution within the tornado as a function of r. ...

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Fluid Description. We will assume the air is an id...

Question: 13.1

Air flows at 5 kg/s through the duct in Fig. 13–2, such that the gage pressure and temperature at A are pA = 80 kPa and TA = 50°C, and at B, pB = 20 kPa and TB = 20°C. Determine the changes in the enthalpy, internal energy, and entropy of the air between these points. ...

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Fluid Description. Because the temperature and pre...

Question: 8.6

A model of the car in Fig. 8–12 is to be constructed to a scale of 1/4 and is to be tested at 20°C in a water tunnel. Determine the required velocity of the water if the actual car is traveling at 30 m/s in air at this same temperature. ...

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Here viscosity creates the predominating force, an...

Question: 7.7

A flow has a velocity field defined by V = {4xy²i + 4x²yj} m/s. Is it possible to establish a potential function for this flow, and if so, what is the equipotential line passing through point x = 1 m, y = 1 m? ...

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Fluid Description. We have steady flow since V is ...

Question: 8.4

A pressure drop Δp provides a measure of the frictional losses of a fluid as it flows through a pipe, Fig. 8–5. Determine how Δp is related to the variables that influence it, namely, the pipe diameter D, its length L, the fluid density ρ, viscosity μ, velocity V, and the relative roughness factor ...

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Define the Physical Variables. In this case, [late...

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: 12.12

The rectangular channel in Fig. 12–27a is made of unfinished concrete and has a slope of S0 = 0.035. When it reaches the check dam, the flow backs up as shown in Fig. 12–27b. At a specific location before the dam, the water has a depth of 1.25 m and the flow is Q = 0.75 m³/s. Classify the surface ...

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Fluid Description. The flow is steady and nonuni...

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 ...

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Fluid Description. We assume that adiabatic stea...

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 compres...

Question: 12.13

Water flows from a reservoir under a sluice gate and into the 1.5-m-wide unfinished concrete rectangular channel, which is horizontal, Fig. 12–28a. At the control point 0, the measured flow is 2 m³/s and the depth is 0.2 m. Show how to determine the variation of the water depth along the channel, ...

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Fluid Description. Assuming the reservoir mainta...

Question: 13.5

Nitrogen flows isentropically through the pipe in Fig. 13–10 such that its gage pressure is p = 200 kPa, the temperature is 80°C, and the velocity is 150 m/s. Determine the stagnation temperature and stagnation pressure for this gas. The atmospheric pressure is 101.3 kPa. ...

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Fluid Description. The Mach number for the flow ...

Question: 13.11

Air flows through the 100-mm-diameter pipe in Fig. 13–23 having an absolute pressure of p_1 = 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 ...

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Fluid Description. We assume steady isentropic f...

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. ...

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Fluid Description. We have steady compressible f...

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. ...

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Fluid Description. The control volume that conta...

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 ...

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