Fluid Mechanics: Fundamentals and Applications
Fluid Mechanics: Fundamentals and Applications
4th Edition
ISBN: 9781259696534
Author: Yunus A. Cengel Dr., John M. Cimbala
Publisher: McGraw-Hill Education
bartleby

Videos

Question
Book Icon
Chapter 8, Problem 93P
To determine

(a)

The electric power consumption of the system for pumping of water.

Expert Solution
Check Mark

Answer to Problem 93P

The electric power consumption of the system for pumping of water is 4160.62kW.

Explanation of Solution

Given information:

The temperature of the water is 110°C, density of the water is 950.6kg/m3, dynamic viscosity of the water is 0.255×103kg/ms, diameter of the pipe is 60cm, roughness of the stainless steel surfaces is 2×106m, specific heat capacity of water is 4.229kJ/kg°C, pump-motor efficiency is 80%, length of the pipe is 12km and volume flow rate of the water is 1.5m3/s.

Write the expression for the Reynolds number.

  Re=ρvDμ........... (I)

Here, Reynolds number is Re, density of the water is ρ, velocity of the water is v, diameter of the pipe is D and dynamic viscosity of the water is μ.

Write the expression for the volume flow rate of the water.

  Q˙=π4D2v........... (II)

Here, the volume flow rate of the water is Q˙.

Write the expression for the friction factor for turbulent flow.

  1f=2log(εD3.7+2.51Ref)........... (III)

Here, friction factor for turbulent flow is f and roughness of the stainless-steel surfaces is ε.

Write the expression for the head loss through the pipe.

  hf=fLv22gD........... (IV)

Here, length of the pipe is L, gravitational acceleration is g and the head loss through the pipe is hf.

Write the expression for the pressure drop through the pipe.

  ΔP=ρghf........... (V)

Here, the pressure drop through the pipe is ΔP.

Write the expression for the electric power consumption of the system for pumping of water.

  W˙pump=Q˙ΔP........... (VI)

Here, electric power consumption of the system for pumping of water is W˙pump.

Write the expression for the Bernoulli Equation.

  P1ρg+v122g+Z1+hpump=P2ρg+v222g+Z2+hf........... (VII)

Here, pressure at point 1 is P1, velocity at point 1 in v1, density of the fluid is ρ, gravitational acceleration is g, elevation of point 1 is Z1, pressure at point 2 is P2, elevation of point 2 is Z2, velocity at point 2 in v2 and head loss in pump is hpump.

Write the expression for the motor-pump efficiency.

  ηpump=W˙pumpW˙electric........... (VIII)

Here, the motor-pump efficiency is ηpump.

Calculation:

Substitute 1.5m3/s for Q˙ and 60cm for D in Equation (II).

  (1.5 m 3/s)=π4(60cm)2v(1.5 m 3/s)=π4(( 60cm)[ 1m 100cm ])2vv=5.305m/s

Substitute 950.6kg/m3 for ρ, 5.305m/s for v, 0.255×103kg/ms for μ and 60cm for D in Equation (I).

  Re=( 950.6 kg/ m 3 )( 5.305m/s )( 60cm)( 0.255× 10 3 kg/ ms )=( 950.6 kg/ m 3 )( 5.305m/s )( 60cm)[ 1m 100cm]( 0.255× 10 3 kg/ ms )=1.187×107

Since, value of the Reynolds number is greater than 4000, therefore flow is turbulent.

Substitute 1.187×107 for Re, 2×106m for ε and 60cm for D in Equation (III).

  1f=2log( ( 2× 10 6 m ) ( 60cm ) 3.7+ 2.51 ( 1.187× 10 7 ) f )12f=log( ( 2× 10 6 m ) ( 60cm )[ 1m 100cm ] 3.7+ 2.51 ( 1.187× 10 7 ) f )f=0.00829

Substitute 0.00829 for f, 12km for L, 5.305m/s for v, 9.81m/s2 for g and 60cm for D in Equation (IV).

  hf=( 0.00829)( 12km) ( 5.305m/s )22( 9.81m/ s 2 )( 60cm)=( 0.00829)( 12km)[ 1000m 1km] ( 5.305m/s )22( 9.81m/ s 2 )( 60cm)[ 1m 100cm]=238m

Substitute 238m for hf, 950.6kg/m3 for ρ and 9.81m/s2 for g in Equation (V).

  ΔP=(950.6kg/ m 3)(9.81m/ s 2)(238m)=(2218× 103kgm/ s 2)(1m 2)[1N1 kgm/ s 2 ][1Pa1N/ m 2 ][1kPa 10 3Pa]=2219kPa

Substitute 1.5m3/s for Q˙ and 2219kPa for ΔP in Equation (VII).

  W˙pump=(1.5 m 3/s)(2219kPa)=(1.5 m 3/s)(2219kPa)[ 10 3Pa1kPa][1N/ m 2 1Pa][1J1Nm][1W1J/s]=(3327× 103W)[1kW1000W]=3328.5kW

Substitute 3328.5kW for W˙pump and 80% for ηpump in Equation (VIII).

  80%=3328.5kW W ˙ electric(80%)[ 10 21%]=3328.5kW W ˙ electricW˙electric=4160.62kW

Conclusion:

The electric power consumption of the system for pumping is 4160.62kW.

To determine

(b)

The daily cost of the power consumption of the system.

Expert Solution
Check Mark

Answer to Problem 93P

The daily cost of the power consumption of the system is $5991.2928day1.

Explanation of Solution

Calculation:

The unit cost of the electricity is $0.06kWh1.

Write the expression for the amount of daily cost of the power consumption.

  A=ctW˙electric........... (IX)

Here, amount of daily cost of the power consumption is A, unit cost is c and time is t.

Substitute $0.06kWh1 for c, 4160.62kW for W˙electric and 24hr/day for t in Equation (IX).

  A=($0.06 kWh 1)(24hr/day)(4160.62kW)=$5991.2928day1

Conclusion:

The daily cost of the power consumption of the system is $5991.2928day1.

To determine

(c)

The frictional heating during flow will make up drop in temperature or not.

Expert Solution
Check Mark

Answer to Problem 93P

The frictional heating during flow will make up drop in temperature.

Explanation of Solution

Given information:

The drop-in temperature of geothermal water during flow is 0.5°C.

Write the expression for the rise in temperature of geothermal water.

  W˙pump=ρQ˙CPΔT........... (X)

Here, rise in temperature of geothermal water during flow is ΔT.

Calculation:

Substitute 950.6kg/m3 for ρ, 3328.5kW for W˙pump, 1.5m3/s for Q˙ and 4.229kJ/kg°C for CP in Equation (X).

  3328.5kW=(950.6kg/ m 3)(1.5 m 3/s)(4.229kJ/kg°C)ΔT(3328.5kW)[1 kJ/s1kW]=(950.6kg/ m 3)(1.5 m 3/s)(4.229kJ/kg°C)ΔTΔT=0.5519°C

Since, rise in temperature of geothermal water due to frictional heating is greater than the drop in temperature of geothermal water during flow, therefore the frictional heating during flow will make up drop in temperature.

Conclusion:

The frictional heating during flow will make up drop in temperature.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Students have asked these similar questions
-6- 8 من 8 Mechanical vibration HW-prob-1 lecture 8 By: Lecturer Mohammed O. attea The 8-lb body is released from rest a distance xo to the right of the equilibrium position. Determine the displacement x as a function of time t, where t = 0 is the time of release. c=2.5 lb-sec/ft wwwww k-3 lb/in. 8 lb Prob. -2 Find the value of (c) if the system is critically damping. Prob-3 Find Meq and Ceq at point B, Drive eq. of motion for the system below. Ш H -7~ + 目 T T & T тт +
Q For the following plan of building foundation, Determine immediate settlement at points (A) and (B) knowing that: E,-25MPa, u=0.3, Depth of foundation (D) =1m, Depth of layer below base level of foundation (H)=10m. 3m 2m 100kPa A 2m 150kPa 5m 200kPa B
W PE 2 43 R² 80 + 10 + kr³ Ø8=0 +0 R²+J+ kr200 R² + J-) + k r² = 0 kr20 kr20 8+ W₁ = = 0 R²+1) R²+J+) 4 lec 8.pdf Mechanical vibration lecture 6 By: Lecturer Mohammed C. Attea HW1 (Energy method) Find equation of motion and natural frequency for the system shown in fig. by energy method. m. Jo 000 HW2// For the system Fig below find 1-F.B.D 2Eq.of motion 8 wn 4-0 (1) -5- m

Chapter 8 Solutions

Fluid Mechanics: Fundamentals and Applications

Ch. 8 - What is hydraulic diameter? How is it defined?...Ch. 8 - Shown here is a cool picture of water being...Ch. 8 - What fluid property is responsible for the...Ch. 8 - In the fully developed region of flow in a...Ch. 8 - Someone claims that the volume flow rate in a...Ch. 8 - Someone claims that the average velocity in a...Ch. 8 - Someone claims that the shear stress at the center...Ch. 8 - Someone claims that in fully developed turbulent...Ch. 8 - How does the wall shear stress w , vary along the...Ch. 8 - How is the friction factor for flow in a pipe...Ch. 8 - Discuss whether fully developed pipe flow is one-,...Ch. 8 - Consider fully developed flow in a circular pipe...Ch. 8 - Consider fully developed laminar how in a...Ch. 8 - Explain why the friction factor is independent of...Ch. 8 - Consider laminar flow of air in a circular pipe...Ch. 8 - Consider fully developed laminar flow in a...Ch. 8 - How is head loss related to pressure loss? For a...Ch. 8 - What is turbulent viscosity? What caused it?Ch. 8 - What is the physical mechanism that causes the...Ch. 8 - The head toss for a certain circular pipe is given...Ch. 8 - The velocity profile for the fully developed...Ch. 8 - Water at 15°C (p = 999.1 kg/m3 and = 1.138 × 10-3...Ch. 8 - Water at 70F passes through...Ch. 8 - Heated air at 1 atm and 100F is to be transported...Ch. 8 - In fully developed laminar flow in a circular...Ch. 8 - The velocity profile in fully developed laminar...Ch. 8 - Repeat Prob. 8-36 for a pipe of inner radius 7 cm.Ch. 8 - Water at 10C (p = 999.7 kg/m3 and = 1.307 ×...Ch. 8 - Consider laminar flow of a fluid through a square...Ch. 8 - Repeat Prob. 8-39 for tribulent flow in smooth...Ch. 8 - Air enters a 10-m-long section of a rectangular...Ch. 8 - Consider an air solar collector that is 1 m wide...Ch. 8 - Oil with p = 876 kg/m3 and = 0.24 kg/m.s is...Ch. 8 - Glycenii at 40 C with p = l22 kg/m3 and = 0.27...Ch. 8 - Air at 1 atm and 60 F is flowing through a 1 ft ×...Ch. 8 - Oil with a density of 850 kg/m3 and kinematic...Ch. 8 - In an air heating system, heated air at 40 C and...Ch. 8 - Glycerin at 40 C with p = 1252 kg/m3 and = 0.27...Ch. 8 - Liquid ammonia at 20 C is flowing through a...Ch. 8 - Consider the fully developed flow of glycerin at...Ch. 8 - The velocity profile for a steady laminar flow in...Ch. 8 - The generalized Bernoulli equation for unsteady...Ch. 8 - What is minor loss in pipe flow? How is the minor...Ch. 8 - Define equivalent length for minor loss in pipe...Ch. 8 - The effect of rounding of a pipe inlet on the loss...Ch. 8 - The effect of rounding of a pipe exit on the loss...Ch. 8 - Which has a greater minor loss coefficient during...Ch. 8 - A piping system involves sharp turns, and thus...Ch. 8 - During a retrofitting project of a fluid flow...Ch. 8 - A horizontal pipe has an abrupt expansion from...Ch. 8 - Consider flow from a water reservoir through a...Ch. 8 - Repeat Prob. 8-62 for a slightly rounded entrance...Ch. 8 - Water is to be withdrawn from an 8-m-high water...Ch. 8 - A piping system equipped with a pump is operating...Ch. 8 - Water is pumped from a large lower reservoir to a...Ch. 8 - For a piping system, define the system curve, the...Ch. 8 - Prob. 68CPCh. 8 - Consider two identical 2-m-high open tanks tilled...Ch. 8 - A piping system involves two pipes of different...Ch. 8 - A piping system involves two pipes of different...Ch. 8 - A piping system involves two pipes of identical...Ch. 8 - Water at 15 C is drained from a large reservoir...Ch. 8 - Prob. 74PCh. 8 - The water needs of a small farm are to be met by...Ch. 8 - Prob. 76EPCh. 8 - A 2.4-m-diameter tank is initially filled with...Ch. 8 - A 3-m-diameter tank is initially filled with water...Ch. 8 - Reconsider Prob. 8-78. In order to drain the tank...Ch. 8 - Gasoline (p = 680 kg/m3 and v = 4.29 × 10-7 m2/s)...Ch. 8 - Prob. 81EPCh. 8 - Oil at 20 C is flowing through a vertical glass...Ch. 8 - Prob. 83PCh. 8 - A 4-in-high cylindrical tank having a...Ch. 8 - A fanner is to pump water at 70 F from a river to...Ch. 8 - A water tank tilled with solar-heated vater at 4OC...Ch. 8 - Two water reservoirs A and B are connected to each...Ch. 8 - Prob. 89PCh. 8 - A certain pail of cast iron piping of a water...Ch. 8 - Repeat Prob. 8-91 assuming pipe A has a...Ch. 8 - Prob. 93PCh. 8 - Repeat Prob. 8-93 for cast lion pipes of the same...Ch. 8 - Water is transported by gravity through a...Ch. 8 - Water to a residential area is transported at a...Ch. 8 - In large buildings, hot water in a water tank is...Ch. 8 - Prob. 99PCh. 8 - Two pipes of identical length and material are...Ch. 8 - What are the primary considerations when selecting...Ch. 8 - What is the difference between laser Doppler...Ch. 8 - Prob. 103CPCh. 8 - Prob. 104CPCh. 8 - Explain how flow rate is measured with...Ch. 8 - Prob. 106CPCh. 8 - Prob. 107CPCh. 8 - Prob. 108CPCh. 8 - A 15-L kerosene tank (p = 820 kg/m3) is filled...Ch. 8 - Prob. 110PCh. 8 - Prob. 111PCh. 8 - Prob. 112PCh. 8 - Prob. 113PCh. 8 - Prob. 114EPCh. 8 - Prob. 115EPCh. 8 - Prob. 116PCh. 8 - A Venturi meter equipped with a differential...Ch. 8 - Prob. 119PCh. 8 - Prob. 120PCh. 8 - Prob. 121PCh. 8 - Prob. 122EPCh. 8 - Prob. 123PCh. 8 - The flow rate of water at 20°C (p = 998 kg/m3 and ...Ch. 8 - Prob. 125PCh. 8 - Prob. 126PCh. 8 - Prob. 127PCh. 8 - The conical container with a thin horizontal tube...Ch. 8 - Prob. 129PCh. 8 - The compressed air requirements of a manufacturing...Ch. 8 - A house built on a riverside is to be cooled iii...Ch. 8 - The velocity profile in fully developed lamina,...Ch. 8 - Prob. 133PCh. 8 - Two pipes of identical diameter and material are...Ch. 8 - Prob. 135PCh. 8 - Shell-and-tube heat exchangers with hundred of...Ch. 8 - Water at 15 C is to be dischaged froiti a...Ch. 8 - Consider flow front a reservoir through a...Ch. 8 - A pipelme ihat Eransports oil ai 4OC at a iate of...Ch. 8 - Repeat Prob. 8-140 for hot-water flow of a...Ch. 8 - Prob. 142PCh. 8 - Prob. 145EPCh. 8 - Prob. 146EPCh. 8 - In a hydroelectric power plant. water at 20°C is...Ch. 8 - Prob. 148PCh. 8 - Prob. 152PCh. 8 - The water at 20 C in a l0-m-diameter, 2-m-high...Ch. 8 - Prob. 155PCh. 8 - Find the total volume flow rate leaving a tank...Ch. 8 - Prob. 158PCh. 8 - Water is siphoned from a reservoir open to the...Ch. 8 - It is a well-known fact that Roman aqueduct...Ch. 8 - In a piping system, what is used to control the...Ch. 8 - Prob. 163PCh. 8 - Prob. 164PCh. 8 - Prob. 165PCh. 8 - Consider laminar flow of water in a...Ch. 8 - Water at 10 C flows in a 1.2-cm-diameter pipe at a...Ch. 8 - Engine oil at 20 C flows in a 15-cm-diamcter pipe...Ch. 8 - Prob. 169PCh. 8 - Watet flows in a I 5-cm-diameter pipe a, a...Ch. 8 - The pressure drop for a given flow is determined...Ch. 8 - Prob. 172PCh. 8 - Air at 1 atm and 25 C flows in a 4-cm-diameter...Ch. 8 - Hot combustion 8ases approximated as air at I atm...Ch. 8 - Air at 1 aim and 40 C flows in a 8-cm-diameter...Ch. 8 - The valve in a piping system cause a 3.1 in head...Ch. 8 - A water flow system involves a 180 return bend...Ch. 8 - Air flows in an 8-cm-diameter, 33-m-long pipe at a...Ch. 8 - Consider a pipe that branches out into two...Ch. 8 - Prob. 182PCh. 8 - Prob. 183PCh. 8 - Prob. 184PCh. 8 - Prob. 185PCh. 8 - Prob. 186PCh. 8 - Design an experiment to measure the viscosity of...Ch. 8 - During a camping trip you notice that water is...
Knowledge Booster
Background pattern image
Mechanical Engineering
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.
Similar questions
SEE MORE QUESTIONS
Recommended textbooks for you
Text book image
Elements Of Electromagnetics
Mechanical Engineering
ISBN:9780190698614
Author:Sadiku, Matthew N. O.
Publisher:Oxford University Press
Text book image
Mechanics of Materials (10th Edition)
Mechanical Engineering
ISBN:9780134319650
Author:Russell C. Hibbeler
Publisher:PEARSON
Text book image
Thermodynamics: An Engineering Approach
Mechanical Engineering
ISBN:9781259822674
Author:Yunus A. Cengel Dr., Michael A. Boles
Publisher:McGraw-Hill Education
Text book image
Control Systems Engineering
Mechanical Engineering
ISBN:9781118170519
Author:Norman S. Nise
Publisher:WILEY
Text book image
Mechanics of Materials (MindTap Course List)
Mechanical Engineering
ISBN:9781337093347
Author:Barry J. Goodno, James M. Gere
Publisher:Cengage Learning
Text book image
Engineering Mechanics: Statics
Mechanical Engineering
ISBN:9781118807330
Author:James L. Meriam, L. G. Kraige, J. N. Bolton
Publisher:WILEY
Intro to Compressible Flows — Lesson 1; Author: Ansys Learning;https://www.youtube.com/watch?v=OgR6j8TzA5Y;License: Standard Youtube License