All Matches

Solution Library

Expert Answer

Textbooks

Search Textbook questions, tutors and Books

Oops, something went wrong!

Change your search query and then try again

Result Not Found

Books FREE
Tutors
Study Help
Hire a Tutor
AI Study Help New

Search
Sign In
Register

study help
engineering
mechanical engineering

Questions and Answers of Mechanical Engineering

Repeat Problem 9-179 by considering the variation of specific heats of air with temperature.
Repeat Problem 9-179 using helium as the working fluid.
Using EES (or other) software, determine the effect of the number of compression and expansion stages on the thermal efficiency of an ideal regenerative Brayton cycle with multistage compression and
Repeat Problem 9-182 using helium as the working fluid.
An Otto cycle with air as the working fluid has a compression ratio of 10.4. Under cold-air-standard conditions, the thermal efficiency of this cycle is (a) 10 percent (b) 39 percent (c) 61 percent
For specified limits for the maximum and minimum temperatures, the ideal cycle with the lowest thermal efficiency is (a) Carnot (b) Stirling (c) Ericsson (d) Otto (e) All are the same
A Carnot cycle operates between the temperature limits of 300 and 2000 K, and produces 600 kW of net power. The rate of entropy change of the working fluid during the heat addition process is (a) 0
Air in an ideal Diesel cycle is compressed from 2 to 0.13 L, and then it expands during the constant pressure heat addition process to 0.30 L. Under cold air standard conditions, the thermal
Helium gas in an ideal Otto cycle is compressedfrom 208C and 2.5 to 0.25 L, and its temperature increases by an additional 7008C during the heat addition process. The temperature of helium before the
In an ideal Otto cycle, air is compressed from 1.20 kg/m3 and 2.2 to 0.26 L, and the net work output of the cycle is 440 kJ/kg. The mean effective pressure (MEP) for this cycle is (a) 612 kPa (b)
An air-standard Carnot cycle is executed in a closed system between the temperature limits of 350 and 1200 K. The pressures before and after the isothermal compression are 150 and 300 kPa,
In an ideal Brayton cycle, air is compressed from 95 kPa and 258C to 1100 kPa. Under cold-air-standard conditions, the thermal efficiency of this cycle is (a) 45 percent (b) 50 percent (c) 62
Consider an ideal Brayton cycle executed between the pressure limits of 1200 and 100 kPa and temperature limits of 20 and 10008C with argon as the working fluid. The net work output of the cycle
An ideal Brayton cycle has a net work output of 150 kJ/kg and a back work ratio of 0.4. If both the turbine and the compressor had an isentropic efficiency of 85 percent, the net work output of the
In an ideal Brayton cycle, air is compressed from 100 kPa and 258C to 1 MPa, and then heated to 9278C before entering the turbine. Under cold-air-standard conditions, the air temperature at the
In an ideal Brayton cycle with regeneration, argon gas is compressed from 100 kPa and 258C to 400 kPa, and then heated to 12008C before entering the turbine. The highest temperature that argon can be
In an ideal Brayton cycle with regeneration, air is compressed from 80 kPa and 108C to 400 kPa and 1758C, is heated to 4508C in the regenerator, and then further heated to 10008C before entering the
Consider a gas turbine that has a pressure ratio of 6 and operates on the Brayton cycle with regeneration between the temperature limits of 20 and 9008C. If the specific heat ratio of the working
An ideal gas turbine cycle with many stages of compression and expansion and a regenerator of 100 percent effectiveness has an overall pressure ratio of 10. Air enters every stage of compressor at
Air enters a turbojet engine at 320 m/s at a rate of 30 kg/s, and exits at 650 m/s relative to the aircraft. The thrust developed by the engine is (a) 5 kN (b) 10 kN (c) 15 kN (d) 20 kN (e) 26 kN
Consider a Carnot cycle executed in a closed system with 0.6 kg of air. The temperature limits of the cycle are 300 and 1100 K, and the minimum and maximum pressures that occur during the cycle are
Consider a Carnot cycle executed in a closed system with air as the working fluid. The maximum pressure in the cycle is 1300 kPa while the maximum temperature is 950 K. If the entropy increase during
An ideal gas is contained in a piston-cylinder device and undergoes a power cycle as follows: 1-2 isentropic compression from an initial temperature T1 = 20oC with a compression ratio r = 5 2-3
What four processes make up the ideal Otto cycle?
An ideal Otto cycle has a compression ratio of 10.5, takes in air at 90 kPa and 40oC, and is repeated 2500 times per minute. Using constant specific heats at room temperature, determine the thermal
An ideal Otto cycle has a compression ratio of 10.5, takes in air at 90 kPa and 40oC, and is repeated 2500 times per minute. Using constant specific heats at room temperature, determine the thermal
An ideal Otto cycle has a compression ratio of 8. At the beginning of the compression process, air is at 95 kPa and 27oC, and 750 kJ/kg of heat is transferred to air during the constant-volume
Using EES (or other) software, study the effect of varying the compression ratio from 5 to 10. Plot the net work output and thermal efficiency as a function of the compression ratio. Plot the T-s and
Repeat Problem 9-33 using constant specific heats at room temperature. Problem 9-33 An ideal Otto cycle has a compression ratio of 8. At the beginning of the compression process, air is at 95 kPa and
A six-cylinder, four-stroke, spark-ignition engine operating on the ideal Otto cycle takes in air at 14 psia and 105oF, and is limited to a maximum cycle temperature of 2400oF. Each cylinder has a
A spark-ignition engine has a compression ratio of 8, an isentropic compression efficiency of 85 percent, and an isentropic expansion efficiency of 95 percent. At the beginning of the compression,
An ideal Otto cycle with air as the working fluid has a compression ratio of 8. The minimum and maximum temperatures in the cycle are 540 and 2400 R. Accounting for the variation of specific heats
An ideal Otto cycle with air as the working fluid has a compression ratio of 8. The minimum and maximum temperatures in the cycle are 540 and 2400 R. Accounting for the variation of specific heats
When we double the compression ratio of an ideal Otto cycle, what happens to the maximum gas temperature and pressure when the state of the air at the beginning of the compression and the amount of
In a spark-ignition engine, some cooling occurs as the gas is expanded. This may be modeled by using a polytropic process in lieu of the isentropic process. Determine if the polytropic exponent used
How does a diesel engine differ from a gasoline engine?
An air-standard Diesel cycle has a compression ratio of 16 and a cutoff ratio of 2. At the beginning of the compression process, air is at 95 kPa and 27oC. Accounting for the variation of specific
Repeat Problem 9-46 using constant specific heats at room temperature. Problem 9-46 An air-standard Diesel cycle has a compression ratio of 16 and a cutoff ratio of 2. At the beginning of the
An ideal Diesel cycle has a compression ratio of 17 and a cutoff ratio of 1.3. Determine the maximum temperature of the air and the rate of heat addition to this cycle when it produces 140 kW of
An ideal Diesel cycle has a maximum cycle temperature of 2300oF and a cutoff ratio of 1.4. The state of the air at the beginning of the compression is P1 = 14.4 psia and T1 = 50oF. This cycle is
An air-standard dual cycle has a compression ratio of 14 and a cutoff ratio of 1.2. The pressure ratio during the constant-volume heat addition process is 1.5. Determine the thermal efficiency,
Repeat Prob. 9-50 when the state of the air at the beginning of the compression is 80 kPa and 220oC. Prob. 9-50 An air-standard dual cycle has a compression ratio of 14 and a cutoff ratio of 1.2. The
An air-standard Diesel cycle has a compression ratio of 18.2. Air is at 1208F and 14.7 psia at the beginning of the compression process and at 3200 R at the end of the heat addition process.
Repeat Prob. 9-52E using constant specific heats at room temperature. Prob. 9-52E An air-standard Diesel cycle has a compression ratio of 18.2. Air is at 1208F and 14.7 psia at the beginning of the
An ideal diesel engine has a compression ratio of 20 and uses air as the working fluid. The state of air at the beginning of the compression process is 95 kPa and 20oC. If the maximum temperature in
Repeat Prob. 9-54, but replace the isentropic expansion process by polytropic expansion process with the polytropic exponent n = 1.35. Use variable specific heats. Prob. 9-54 An ideal diesel engine
Reconsider Prob. 9-55. Using EES (or other) software, study the effect of varying the compression ratio from 14 to 24. Plot the net work output, mean effective pressure, and thermal efficiency as a
A four-cylinder two-stroke 2.4-L diesel engine that operates on an ideal Diesel cycle has a compression ratio of 22 and a cutoff ratio of 1.8. Air is at 70oC and 97 kPa at the beginning of the
Repeat Prob. 9-57 using nitrogen as the working fluid. Prob. 9-57 A four-cylinder two-stroke 2.4-L diesel engine that operates on an ideal Diesel cycle has a compression ratio of 22 and a cutoff
An ideal dual cycle has a compression ratio of 15 and a cutoff ratio of 1.4. The pressure ratio during constant volume heat addition process is 1.1. The state of the air at the beginning of the
The compression ratio of an ideal dual cycle is 14. Air is at 100 kPa and 300 K at the beginning of the compression process and at 2200 K at the end of the heat-addition process. Heat transfer to air
Reconsider Problem 9-60. Using EES (or other) software, study the effect of varying the compression ratio from 10 to 18. For the compression ratio equal to 14, plot the T-s and P-v diagrams for the
Repeat Problem 9-60 using constant specific heats at room temperature. Is the constant specific heat assumption reasonable in this case? Problem 9-60 The compression ratio of an ideal dual cycle is
Develop an expression for cutoff ratio rc which expresses it in terms of qin/(cpT1rk-1) for an air-standard Diesel cycle.
An air-standard cycle, called the dual cycle, with constant specific heats is executed in a closed piston-cylinder system and is composed of the following five processes: 1-2 Isentropic compression
An ideal Ericsson engine using helium as the working fluid operates between temperature limits of 550 and 3000 R and pressure limits of 25 and 200 psia. Assuming a mass flow rate of 14 lbm/s,
An ideal Stirling engine using helium as the working fluid operates between temperature limits of 300 and 2000 K and pressure limits of 150 kPa and 3 MPa. Assuming the mass of the helium used in the
Consider an ideal Ericsson cycle with air as the working fluid executed in a steady-flow system. Air is at 27°C and 120 kPa at the beginning of the isothermal compression process, during which 150
An ideal Stirling cycle filled with air uses a 758F energy reservoir as a sink. The engine is designed so that the maximum air volume is 0.5 ft3, the minimum air volume is 0.06 ft3, and the minimum
Repeat Prob. 9-72E if the engine is to be operated to produce 2.5 Btu of work for the same external heat input? Prob. 9-72E An ideal Stirling cycle filled with air uses a 758F energy reservoir as a
An air-standard Stirling cycle operates with a maximum pressure of 3600 kPa and a minimum pressure of 50 kPa. The maximum volume is 12 times the minimum volume, and the low-temperature reservoir is
How much heat is stored (and recovered) in the regenerator of Prob. 9-74. Use constant specific heats at room temperature. Prob. 9-74. An air-standard Stirling cycle operates with a maximum pressure
As a car gets older, will its compression ratio change? How about the mean effective pressure?
A simple ideal Brayton cycle with air as the working fluid has a pressure ratio of 10. The air enters the compressor at 520 R and the turbine at 2000 R. Accounting for the variation of specific heats
A gas-turbine power plant operates on the simple Brayton cycle with air as the working fluid and delivers 32 MW of power. The minimum and maximum temperatures in the cycle are 310 and 900 K, and the
Repeat Problem 9-81 using constant specific heats at room temperature. Problem 9-81 A gas-turbine power plant operates on the simple Brayton cycle with air as the working fluid and delivers 32 MW of
A simple Brayton cycle using air as the working fluid has a pressure ratio of 10. The minimum and maximum temperatures in the cycle are 295 and 1240 K. Assuming an isentropic efficiency of 83 percent
Reconsider Prob. 9-83. Using EES (or other) software, allow the mass flow rate, pressure ratio, turbine inlet temperature, and the isentropic efficiencies of the turbine and compressor to vary.
A simple Brayton cycle using air as the working fluid has a pressure ratio of 10. The minimum and maximum temperatures in the cycle are 295 and 1240 K. Assuming an isentropic efficiency of 83 percent
Consider a simple Brayton cycle using air as the working fluid; has a pressure ratio of 12; has a maximum cycle temperature of 600°C; and operates the compressor inlet at 100 kPa and 15°C.
Air is used as the working fluid in a simple ideal Brayton cycle that has a pressure ratio of 12, a compressor inlet temperature of 300 K, and a turbine inlet temperature of 1000 K. Determine the
An aircraft engine operates on a simple ideal Brayton cycle with a pressure ratio of 10. Heat is added to the cycle at a rate of 500 kW; air passes through the engine at a rate of 1 kg/s; and the air
Repeat Prob. 9-88 for a pressure ratio of 15. Prob. 9-88 An aircraft engine operates on a simple ideal Brayton cycle with a pressure ratio of 10. Heat is added to the cycle at a rate of 500 kW; air
What is the difference between spark-ignition and compression-ignition engines?
A gas-turbine power plant operates on the simple Brayton cycle between the pressure limits of 100 and 1600 kPa. The working fluid is air, which enters the compressor at 408C at a rate of 850 m3/min
A gas-turbine power plant operates on a simple Brayton cycle with air as the working fluid. The air enters the turbine at 120 psia and 2000 R and leaves at 15 psia and 1200 R. Heat is rejected to the
For what compressor efficiency will the gas-turbine power plant in Problem 9-91E produce zero net work? Problem 9 - 91E A gas-turbine power plant operates on a simple Brayton cycle with air as the
A gas-turbine power plant operates on the simple Brayton cycle between the pressure limits of 100 and 800 kPa. Air enters the compressor at 30°C and leaves at 330°C at a mass flow rate of 200 kg/s.
A gas-turbine power plant operates on a modified Brayton cycle shown in the figure with an overall pressure ratio of 8. Air enters the compressor at 0°C and 100 kPa. The maximum cycle temperature is
How does regeneration affect the efficiency of a Brayton cycle, and how does it accomplish it?
Somebody claims that at very high pressure ratios, the use of regeneration actually decreases the thermal efficiency of a gas-turbine engine. Is there any truth in this claim? Explain.
In 1903, Aegidius Elling of Norway designed and built an 11-hp gas turbine that used steam injection between the combustion chamber and the turbine to cool the combustion gases to a safe temperature
A gas turbine for an automobile is designed with a regenerator. Air enters the compressor of this engine at 100 kPa and 30°C. The compressor pressure ratio is 10; the maximum cycle temperature is
Why is the Carnot cycle not a realistic model for steam power plants?
Consider a cogeneration power plant that is modified with reheat and that produces 3 MW of power and supplies 7 MW of process heat. Steam enters the high-pressure turbine at 8 MPa and 500°C and
Atmospheric air enters the air compressor of a simple combined gas-steam power system at 14.7 psia and 80°F. The air compressor's compression ratio is 10; the gas cycle's maximum temperature is
It has been suggested that the steam passing through the condenser of the combined cycle in Prob. 10-101E berouted to buildings during the winter to heat them. When this is done, the pressure in the
During winter, the system of Prob. 10-102E must supply 2 × 106 Btu/h of heat to the buildings. What is the mass flow rate of air through the air compressor and the system's total electrical power
The gas-turbine cycle of a combined gas-steam power plant has a pressure ratio of 12. Air enters the compressor at 310 K and the turbine at 1400 K. The combustion gases leaving the gas turbine are
Repeat Prob. 10-104 assuming isentropic efficiencies of 100 percent for the pump, 85 percent for the compressor, and 90 percent for the gas and steam turbines. Prob. 10-104 The gas-turbine cycle of a
An ideal Rankine steam cycle modified with two closed feedwater heaters and one open feedwater heater is shown below. The power cycle receives 100 kg/s of steam at the high pressure inlet to the
A steam power plant operates on an ideal reheat- regenerative Rankine cycle with one reheater and two feedwater heaters, one open and one closed. Steam enters the high-pressure turbine at 15 MPa and
Using EES (or other) software, investigate the effect of the boiler pressure on the performance of a simple ideal Rankine cycle. Steam enters the turbine at 500°C and exits at 10 kPa. The boiler
Using EES (or other) software, investigate the effect of the condenser pressure on the performance of a simple ideal Rankine cycle. Turbine inlet conditions of steam are maintained constant at 10 MPa
Using EES (or other) software, investigate the effect of reheat pressure on the performance of an ideal Rankine cycle. The maximum and minimum pressures in the cycle are 15 MPa and 10 kPa,
Using EES (or other) software, investigate the effect of extraction pressure on the performance of an ideal regenerative Rankine cycle with one open feedwater heater. Steam enters the turbine at 15
Show that the thermal efficiency of a combined gas-steam power plant ï¨cc can be expressed aswhere ï¨g = Wg /Qin and ï¨s = Ws /Qg,out are the thermal
It can be shown that the thermal efficiency of a combined gas-steam power plant ï¨cc can be expressed in terms of the thermal efficiencies of the gas- and the steamturbine cycles
Starting with Eq. 10-20, show that the exergy destruction associated with a simple ideal Rankine cycle can be expressed as xdest = qin(th,Carnot - th), where th is efficiency of the Rankine
A steam power plant operates on a simple ideal Rankine cycle between the pressure limits of 3 MPa and 50 kPa. The temperature of the steam at the turbine inlet is 300°C, and the mass flow rate of

Showing 14400 - 14500 of 18208

First
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
Last

Services

Sitemap
Fun
Definitions
Become Tutor
Study Help Categories
Recent Questions
Expert Questions

Company Info

Security
Copyrights
Privacy Policy
Terms & Conditions
SolutionInn Fee
Scholarship

Get In Touch

About Us
Contact Us
Career
Jobs
FAQ
Campus Ambassador

Secure Payment

Download Our App

© 2024 SolutionInn. All Rights Reserved