Explanation Draw the P − ν diagram for an ideal Otto cycle as shown in Figure (1). Consider, the pressure is P i , the specific volume is v i , the temperature is T i , the entropy is s i , the enthalpy is h i corresponding to i t h state. F o r c o m p r e s s i o n r a t i o ( r ) . Write the expression for temperature at the end of the compression process 1-2. T 2 T 1 = ( v 1 v 2 ) k − 1 T 2 = T 1 ( r ) k − 1 Here , specific heat ratio is k and compression ratio is r . The temperature rise during combustion remains constant. Thus, the amount of heat addition remains constant Write the expression for maximum temperature. q i n = c v ( T 3 − T 2 ) kJ / kg T 3 = q i n c v + T 2 (I) Here, specific heat at constant volume is c v Write the expression to obtain smallest gas specific volume at state 3 ( v 3 ) during the cycle. v 3 = v 1 r Ideal gas equation is applied for sate 3. P 3 v 3 = R T 3 P 3 = R T 3 v 3 (II) T h e c o m p r e s s i o n r a t i o i s d o u b l e d ( 2 r ) : Write the expression for temperature at the end of the compression process 1-2 when the compression ratio is doubled. T 2 ' T 1 ' = ( 2 r ) k − 1 T 2 ' = T 1 ' ( 2 r ) k − 1 Write the expression for maximum temperature ( T 3 ) when the compression ratio is doubled. q i n = c v ( T 3 ' − T 2 ' ) kJ / kg T 3 ' = q i n c v + T 2 ' (III) Write the expression to obtain smallest gas specific volume at state 3 ( v 3 ) when the compression ratio is doubled. v 3 ' = v 1 ' 2 r Ideal gas equation is applied for sate 3 when the compression ratio is doubled. P 3 ' v 3 ' = R T 3 ' P 3 ' = R T 3 ' v 3 ' (IV) Conclusion: Substitute T 1 ( r ) k − 1 for T 2 in Equation (I)

8th Edition

ISBN: 9780100257054

Author: CENGEL

Publisher: YUZU

See similar textbooks

Concept explainers

IC engines

The term "engine" indicates a mechanical device/machine used to convert input energy to a specific mechanical output. The input energy may be in the form of chemical energy, thermal energy, or so on and mechanical output is in the form of mechanical ener…

Question

Chapter 9.12, Problem 40P

To determine

What happens to the maximum gas temperature, pressure and heat addition when the compression ratio is doubled for an ideal Otto cycle?

Expert Solution & Answer

Want to see the full answer?

Check out a sample textbook solution

See solution

Chapter 9.12, Problem 39P

Chapter 9.12, Problem 41P

Students have asked these similar questions

3. A 15% magnesium chloride solution is flowing through a 5-nom sch 40 commercial steel pipe at a rate of 325,000 lbm/h. The average temperature of the magnesium chloride solution as it flows through the pipe is 10°F. Determine the convective heat transfer coefficient inside the pipe.

2. Jojoba oil is flowing through a ¾-nom stainless steel pipe at a flow rate of 1,850 lbm/h. After the velocity profile in the pipe is fully developed, the oil enters a heater, as shown in Figure P5.7. The length of the heater section is 5 ft. The properties of the jojoba oil at the average temperature in the heater section are given in Table P5.7. Determine the convective heat transfer coefficient inside the heater section of the pipe. ¾ nom stainless steel pipe Heater section L=5ft Fig. P5.7 TABLE P5.7 Thermophysical Properties of Jojoba Oil at the Average Temperature in the Heater P (lbm/ft³) 68.671 (Btu/lbm-R) 0.30339 μ (lbm/ft-s) 0.012095 k (Btu/h-ft-°F) 0.077424

1. Water is flowing inside of a 3-std type K copper tube at a flow rate of 1.2 kg/s. The average temperature of the water is 50°C. Cold, dry air at a temperature of 5°C and atmospheric pressure flows outside of the tube in cross flow with a velocity of 85 m/s. Determine the UA product for this tube under clean conditions.

Chapter 9 Solutions

EBK THERMODYNAMICS: AN ENGINEERING APPR

Ch. 9.12 - What are the air-standard assumptions?Ch. 9.12 - What is the difference between air-standard...Ch. 9.12 - How does the thermal efficiency of an ideal cycle,...Ch. 9.12 - What does the area enclosed by the cycle represent...Ch. 9.12 - Prob. 5P Ch. 9.12 - Prob. 6P Ch. 9.12 - Can the mean effective pressure of an automobile...Ch. 9.12 - Prob. 8P Ch. 9.12 - What is the difference between spark-ignition and...Ch. 9.12 - Prob. 10P

Knowledge Booster

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.

What happens to the maximum gas temperature, pressure and heat addition when the compression ratio is doubled for an ideal Otto cycle?

Solution Summary: The author analyzes the gas temperature, pressure, and heat addition when the compression ratio is doubled for an ideal Otto cycle.

Concept explainers

What happens to the maximum gas temperature, pressure and heat addition when the compression ratio is doubled for an ideal Otto cycle?

Want to see the full answer?

Chapter 9 Solutions