Questions and Answers of Fox And McDonald S Introduction To Fluid Mechanics

12.24 Air flows isentropically through a converging nozzle attached to a large tank, where the absolute pressure is 171 kPa and the temperature is 27 C. At the inlet section the Mach number is
12.17 Oxygen discharges from a tank through a convergent nozzle.The temperature and velocity in the jet are −20 C and 270 m/s, respectively. Determine the temperature in the tank and the
12.18 The hot gas stream at the turbine inlet of a JT9-D jet engine is at 1500 C, 140 kPa absolute, and M =0 32. Calculate the critical conditions (temperature, pressure, and flow speed) that
12.19 Carbon dioxide discharges from a tank through a convergent nozzle with a diameter of 4 mm into the atmosphere. If the tank temperature and gage pressure are 38 C and 140 kPa, respectively,
12.20 Air at 100 F and 100 psia in a large tank flows into a 6-in.-diameter pipe, from which it discharges to the atmosphere at 15.0 psia through a convergent nozzle of 4-in. tip-diameter. Calculate
12.21 Air at a pressure and temperature of 100 in. of mercury absolute and 100 F, respectively, discharges at a rate of 5 lbm/s from a tank through a convergent-divergent nozzle into another tank
12.22 Air flows adiabatically through a duct. At the entrance, the static temperature and pressure are 310 K and 200 kPa, respectively.At the exit, the static and stagnation temperatures are 294 K
12.32 A supersonic aircraft cruises at M =2 2 at 12 km altitude.A pitot tube is used to sense pressure for calculating air speed.A normal shock stands in front of the tube. Evaluate the local
Air flows through a long duct of constant area at 0 15 kg s. A short section of the duct is cooled by liquid nitrogen that surrounds the duct. The rate of heat loss in this section is 15 0 kJ s from
For an ideal gas, find the equations for lines of (a) constant volume and (b) constant pressure in the Ts plane.
Air speed is calculated from pitot tube measurements in a wind tunnel. From the Bernoulli equation,where h is the observed height of the manometer column.The only new element in this example is the
The nozzle of Example 12.10 has a design back pressure of 87.5 kPa (abs) but is operated at a back pressure of 50.0 kPa (abs).Assume flow within the nozzle is isentropic. Determine the exit Mach
A normal shock stands in a duct. The fluid is air, which may be considered an ideal gas. Properties upstream from the shock are T1 =5 C, p1 =65 0 kPa abs , and V1 =668 m s. Determine properties
The observed height of the mercury barometer column is h=752 6 mm. The least count on the vernier scale is 0 1 mm, so one might estimate the probable measurement error as 0 05 mm.A measurement
Obtain an expression for the uncertainty in determining the volume of a cylinder from measurements of its radius and height.The volume of a cylinder in terms of radius and height isDifferentiating,
Air flows isentropically in a converging-diverging nozzle, with exit area of 0 001 m2. The nozzle is fed from a large plenum where the stagnation conditions are 350 K and 1.0 MPa (abs). The exit
Air flows isentropically through a converging nozzle. At a section where the nozzle area is 0 013 ft2, the local pressure, temperature, and Mach number are 60 psia, 40 F, and 0.52, respectively. The
A converging nozzle, with a throat area of 0 001 m2, is operated with air at a back pressure of 591 kPa (abs). The nozzle is fed from a large plenum chamber where the absolute stagnation pressure and
Air flows isentropically in a channel. At section 1, the Mach number is 0.3, the area is 0 001 m2, and the absolute pressure and the temperature are 650 kPa and 62 C, respectively. At section 2 , the
We have derived equations for p0 p for both compressible and incompressible flows. By writing both equations in terms of Mach number, compare their behavior. Find the Mach number below which the two
Air flows steadily through the duct shown from 350 kPa (abs), 60 C, and 183 m s at the inlet state to M =1 3 at the outlet, where local isentropic stagnation conditions are known to be 385 kPa (abs)
In tests of a protective material, we wish to photograph a bullet as it impacts a jacket made of the material. A camera is set up a perpendicular distance h=5 m from the bullet trajectory. We wish to
Find the speed of sound in (a) steel Eν200GN m2 , (b) water (at 20 C), (c) seawater (at 20 C), and (d) air at sea level on a standard day.
12.16 Air flows from the atmosphere into an evacuated tank through a convergent nozzle of 38-mm tip diameter. If atmospheric pressure and temperature are 101.3 kPa and 15 C, respectively, determine
Performance curves [14] are given below for a centrifugal fan with D=36 in and N =600 rpm, as measured on a test stand using cool air ρ=0 075 lbm ft3 . Scale the data to predict the performance of a
The flow system used to test a centrifugal pump at a nominal speed of 1750 rpm is shown. The liquid is water at 80 F, and the suction and discharge pipe diameters are 6 in. Data measured during the
11.14 Water, at 3 ft s and 2 ft depth, approaches a smooth rise in a wide channel. Estimate the stream depth after the 0.5 ft rise. V = 3 ft y=2ft L0.5 ft P11.14
In a vertical-shaft Francis turbine the available head at the inlet flange of the turbine is 500 ft and the vertical distance between the runner and the tailrace is 6.5 ft. The runner tip speed is
11.11 Consider the Venturi flume shown. The bed is horizontal, and the flow may be considered frictionless. The upstream depth is 1 ft, and the downstream depth is 0.75 ft. The upstream breadth is 2
11.4 Capillary waves (ripples) are small amplitude and wavelength waves, commonly seen, for example, when an insect or small particle hits the water surface. They are waves generated due to the
+ Consider the hypothetical impulse turbine installation shown. Analyze flow in the penstock to develop an expression for the optimum turbine output power as a function of jet diameter, Dj. Obtain an
A hydraulic jump occurs in a rectangular channel 3 m wide. The water depth before the jump is 0.6 m, and after the jump is 1.6 m.Compute (a) the flow rate in the channel, (b) the critical depth, (c)
Water flows in a 5-m-wide rectangular channel made from unfinished concrete with n=0 015. The channel contains a long reach on which Sb is constant at Sb =0 020. At one section, flow is at depth y1
A rectangular, sharp-crested suppressed weir 3 m long is 1 m high. Determine the discharge when the head is 150 mm.
12.1 Air is expanded in a steady flow process through a turbine.Initial conditions are 1300 C and 2.0 MPa absolute. Final conditions are 500 C and atmospheric pressure. Show this process on a Ts
12.2 Hydrogen flows as a perfect gas without friction in the pipe shown in the figure. Determine the outlet velocity when 7.5 × 105 J/kg of heat is added. 75 m/s T = 50C T = 100C P12.2
12.3 Air enters a turbine in steady flow at 0 5 kg s with negligible velocity. Inlet conditions are 1300 C and 2.0 MPa absolute. The air is expanded through the turbine to atmospheric pressure. If
12.4 Carbon dioxide at 150 C and 120 kPa absolute flows at a speed of 10 m/s in a pipe and discharges through a nozzle where the exit velocity is 50 m/s. Determine the temperature and pressure
12.5 Calculate the speed of sound at 20 C for (a) hydrogen,(b) helium, (c) methane, (d) nitrogen, (e) carbon dioxide and (f) air.Draw some conclusion from the results.
12.6 An airplane flies at 550 km hr at 1500 m altitude on a standard day. The plane climbs to 15,000 m and flies at 1200 km h. Calculate the Mach number of flight in both cases.
12.9 A photograph of a bullet shows a Mach angle of 32 . Determine the speed of the bullet for standard air.
12.10 An aircraft flying at a Mach number of 1.5 passes overhead at 3 km altitude. Determine the air speed of the aircraft. If a headwind blows at 30 m/s, determine how long after the aircraft passes
12.11 Determine the air density in the undisturbed air and at the stagnation point of an aircraft flying at 400 m/s in air at 28 kPa and 5 C. Determine the percentage increase in density and whether
12.12 A supersonic wind tunnel test section is designed to have M =2 5 at 15 C and 35 kPa absolute. The fluid is air. Determine the required inlet stagnation conditions, T0 and p0. Calculate the
12.13 Oxygen flows in a duct at a pressure of 25 psia. The pressure and temperature on the nose of a small object in the flow are 28 psia and 150 F, respectively. Determine the velocity in duct.
12.14 Consider steady, adiabatic flow of air through a long straight pipe with A=0 05 m2. At the inlet section the air is at 200 kPa absolute, 60 C, and 146 m s. Downstream at section , the air is at
An above-ground flume, built from timber, is to convey water from a mountain lake to a small hydroelectric plant. The flume is to deliver water at Q=2m3 s; the slope is Sb =0 002 and n=0 013.
11.23 A channel with square cross section is to carry 20 m3/s of water at normal depth on a slope of 0.003. Determine the cross-sectional area and wetted perimeter of the channel required for(a)
11.22 A rectangular flume built of timber is 3 ft wide. The flume is to handle a flow of 90 ft3 s at a normal depth of 6 ft. Determine the slope required.
11.21 Determine the uniform flow depth in a rectangular channel 8 ft wide with a slope of 0.0004 that carries a discharge of 90 cfs.Manning’s roughness factor is 0.015.
11.20 A 2-m-wide rectangular channel with a bed slope of 0.0005 has a depth of flow of 1.5 m. Manning’s roughness coefficient is 0.015. Determine the steady uniform discharge in the channel.
11.19 A hydraulic jump occurs in a rectangular channel. The flow rate is 50 m3 s and the depth before the jump is 2 m.Determine the depth after the jump and the head loss if the channel is 1 m wide.
11.18 A hydraulic jump occurs on a spillway at a location where depth is 0.9 m and speed is 25 m/s. Determine the depth and speed downstream of the jump. Determine the ratio of the specific energy
11.17 A hydraulic jump occurs in a rectangular channel. The flow rate is 200 ft3 s, and the depth before the jump is 1.2 ft. Determine the depth behind the jump and the head loss. The channel is 10
Determine the normal depth (for uniform flow) if the channel described in Example 11.6 has a flow rate of 100 cfs.
11.16 A hydraulic jump occurs in a wide horizontal channel carrying 2 m3/s per meter of width. The upstream depth is 0.5 m. Determine the depth and velocity of the water after the jump.
Open channels, of square and semicircular shapes, are being considered for carrying flow on a slope of Sb =0 001; the channel walls are to be poured concrete with n=0 015. Evaluate the flow rate
11.15 A hydraulic jump occurs in a rectangular channel 4.0 m wide.The water depth before the jump is 0.4 m and after the jump is 1.7 m.Compute the flow rate in the channel, the critical depth, and
11.13 Determine the depths of an 800 cfs flow in a trapezoidal channel of base width 12 ft and side slopes 1 (vertical) on 3 (horizontal)for a specific energy of 7 ft.
11.24 Determine the depth for a 4.25 m3/s flow in a rectangular channel 3.6 m wide that is lined with rubble masonry and laid on a slope of 1:4000.
11.25 A semicircular trough of corrugated steel, with diameter D=1 m, carries water at depth y=0 25 m. The slope is 0.01. Find the discharge.
11.12 A horizontal rectangular channel 3 ft wide contains a sluice gate. Upstream of the gate the depth is 6 ft and downstream the depth is 0.9 ft. Determine the volume flow rate and the upstream and
11.10 A rectangular channel carries a discharge of 10 ft3 s per foot of width. Determine the minimum specific energy possible for this flow. Compute the corresponding flow depth and speed.
11.26 Determine the slope is necessary to carry 11 m3/s at a depth of 1.5 m in a rectangular channel 3.6 m wide lined with gravel.
11.9 Determine the maximum flow rate that may occur in a rectangular channel 2.4 m wide for a specific energy of 1.5 m.
11.27 For a trapezoidal shaped channel with n=0 014 and slope Sb =0 0002 with a 20-ft bottom width and side slopes of 1 vertical to 1.5 horizontal, determine the normal depth for a discharge of 1000
11.8 Find the critical depth for flow at 3 m3 s in a rectangular channel of width 2.5 m.
11.7 A water flow of 10 m3/s in a 5-m-wide rectangular channel with a depth of 2.5 m accelerates under a sluice gate. Determine the depth and Froude number of the accelerated flow.
11.6 Verify the equation given in Table 11.1 for the hydraulic radius of a circular channel. Evaluate and plot the ratio R D for liquid depths between 0 and D.
11.5 Waves on the surface of a tank of water on Earth travel at 5 ft/s.Determine the wave speed if the tank were (a) on the moon, (b) on Jupiter, or (c) on an orbiting space station. Explain your
11.3 Determine and plot the relation between water velocity and depth over the range of V = 0 1m s to 10m s for Froude numbers of 0.5 (subcritical), 1.0 (critical), and 2 (supercritical). Explain how
11.28 A trapezoidal canal lined with brick has side slopes of 2:1 and bottom width of 10 ft. It carries 600 ft3 s at critical speed. Determine the critical slope (the slope at which the depth is
11.2 A water flow rate of 250 cfs flows at a depth of 5 ft in a rectangular channel that is 9 ft wide. Determine whether the flow is sub- or supercritical. For this flow rate, determine the depth for
11.1 A pebble is dropped into a stream of water that flows in a rectangular channel at 2 m depth. In one second, a ripple caused by the stone is carried 7 m downstream. Determine the speed of the
A 1/5 scale model of a prototype air compressor consuming 300 hp and running at a speed of 1000 rpm delivers a flow rate of 20 lbm s through a pressure ratio of 5. At dynamically and kinematically
Develop general expressions for thrust, power output, and efficiency of an idealized windmill, as shown in Fig. 10.41. Calculate the thrust, ideal efficiency, and actual efficiency for the Dutch
Use blade element theory to estimate the start-up thrust and torque for a propeller consisting of N independent blades with constant chord length,c, and at a constant angle, θ, with respect to the
Consider the Pelton wheel and single-jet arrangement shown, in which the jet stream strikes the bucket tangentially and is turned through angle θ. Obtain an expression for the torque exerted by the
11.29 Determine the discharge for a sharp-crested suppressed weir of length 8.0 ft, crest height of 2.0 ft, and upstream water depth of 3.0 ft. Neglect the velocity of approach head.
11.30 A rectangular sharp-crested weir with end contractions is 1.5 m long. Determine the necessary height of the weir crest to maintain an upstream depth of 2.5 m for a flow rate of 0.5 m3/s.
A hydraulic pump with performance characteristics represented in Fig. 10.28 delivers a flow rate of 48.5 gpm at zero pressure and 46.5 gpm at 1500 psig at a rotating speed of 2000 rpm. The
The pump of Example 10.6, operating at 1750 rpm, is used to pump water through the pipe system of Fig. 10.18a. Develop an algebraic expression for the general shape of the system resistance curve.
11.31 Determine the depth of water behind a rectangular sharpcrested weir 1.5 m wide and 1.2 m high for a flow of 0.28 m3/s.Determine the velocity of approach.
A Peerless Type 4AE11 centrifugal pump (Fig. C.3, Appendix C) is tested at 1750 rpm using a flow system with the layout of Example 10.4. The water level in the inlet reservoir is 3.5 ft above the
11.32 A broad-crested weir 0.9 m high and 6 m long has a flat crest and a coefficient of 1.6. Determine the flow rate for a head of 0.46 m.
When operated at N =1170 rpm, a centrifugal pump, with impeller diameter D=8 in , has shutoff head H0 =25 0 ft of water. At the same operating speed, best efficiency occurs at Q=300 gpm, where the
11.33 Determine the flow for a 90 V-notch weir for a head of 1.5 ft.Determine the flow rate if the head doubles to 3.0 ft.
Pump test data and performance were given in Example 10.4. Fit a parabolic curve, H =H0−AQ2, to these calculated pump performance results and compare the fitted curve with the measured data
• Describe the effect of Froude number on the characteristics of open channel flow.
You are enjoying a summer’s afternoon relaxing in a rowboat on a pond. You decide to find out how deep the water is by splashing your oar and timing how long it takes the wave you produce to reach
An axial-flow fan operates at 1200 rpm. The blade tip diameter is 1.1 m and the hub diameter is 0.8 m. The inlet and exit angles at the mean blade radius are 30 and 60 , respectively. Inlet guide
At the best efficiency point, a centrifugal pump, with impeller diameter D=8 in., produces H =21 9 ft at Q=300 gpm with N =1170 rpm. Compute the corresponding specific speeds using: (a) U.S.
A centrifugal pump is used to pump 150 gpm of water. The water enters the impeller axially through a 1.25-in.-diameter inlet. The inlet velocity is axial and uniform. The impeller outlet diameter is
Describe the different types of turbomachines used for power production and moving fluids
For a rectangular channel of width b=10 m, construct a family of specific energy curves for Q=0, 2, 5, and 10 m3 s. What are the minimum specific energies for these curves?
A steep-sided triangular section channel α=60∘ has a flow rate of 300 m3 s. Find the critical depth for this flow rate. Verify that the Froude number is unity.
A rectangular channel 2 m wide has a flow of 2 4m3 s at a depth of 1.0 m. Determine whether critical depth occurs at (a) a section where a bump of height h=0 20 m is installed across the channel bed,
An 8-ft-wide rectangular channel with a bed slope of 0 0004 ft ft has a depth of flow of 2 ft. Assuming steady uniform flow, determine the discharge in the channel. The Manning roughness coefficient
12.15 Air passes through a normal shock in a supersonic wind tunnel. Upstream conditions are M1 =1 8, T1 =270 K, and p1 =10 0 kPa absolute. Downstream conditions are M2 =0 6165,T2 =413 6 K, and p2
8.55 A laminar flow meter for measuring air flow is constructed of small diameter (0.2 cm) tubes that are 20 cm long. For an upper limit on the Reynolds number needed to maintain laminar flow of

Showing 600 - 700 of 1063