Explanation Write the given equation of state. v = R T p + B − A R T Partially differentiate the equation of state with respect to temperature by keeping the pressure as constant. ( ∂ v ∂ T ) p = R p + A R T 2 (I) Here, the change in the specific volume with respect to change in the temperature at constant pressure is ( ∂ v ∂ T ) p . the specific volume is v , the gas constant is R , the temperature is T , the pressure of the gas is p and the constant are A and B . Write the expression for change in entropy. s ( p 2 , T ) − s ( p 1 , T ) = − ∫ p 1 p 2 ( ∂ v ∂ T ) p d p (II) Here, the specific entropy at state 2 is s ( p 2 , T ) , the specific entropy at state 1 is s ( p 1 , T ) , the final pressure is p 2 and the initial pressure is p 1 . Write the expression for the change in enthalpy. h ( p 2 , T ) − h ( p 1 , T ) = ∫ p 1 p 2 ( v − T ( ∂ v ∂ T ) p ) d p (III) Here, the specific enthalpy at state 2 is h ( p 2 , T ) and the specific enthalpy at state 1 is h ( p 1 , T ) . Write the expression for difference in the specific enthalpy. h ( p 2 , T ) − h ( p 1 , T ) = u ( p 2 , T ) − u ( p 1 , T ) − ( p 2 v 2 − p 1 v 1 ) (IV) Here, the change in internal energy at state 1 is u ( p 2 , T ) , the change in internal energy at state 2 is u ( p 1 , T ) , the change in specific enthalpy at state 1 is h ( p 2 , T ) and the change in specific at state 2 is u ( p 1 , T ) . Conclusion: Substitute R p + A R T 2 for ( ∂ v ∂ T ) p in the Equation (II). s ( p 2 , T ) − s ( p 1 , T ) = − ∫ p 1 p 2 ( R p + A R T 2 ) d p = − R ln ( p 2 p 1 ) − A R T 2 ( p 2 − p 1 ) Thus, the expression for entropy change is s ( p 2 , T ) − s ( p 1 , T ) = − R ln ( p 2 p 1 ) − A R T 2 ( p 2 − p 1 )

Fundamentals of Engineering Thermodynamics

8th Edition

ISBN: 9781118412930

Author: Michael J. Moran, Howard N. Shapiro, Daisie D. Boettner, Margaret B. Bailey

Publisher: WILEY

See similar textbooks

Concept explainers

Entropy

In physics, entropy means the amount of disorder or the degree of randomness associated with a thermodynamic system. The system is not self-organized when the entropy of the system is high. For instance, when a system is at an elevated temperature, its m…

Videos

Question

Chapter 11.9, Problem 48P

To determine

The expression for the change in specific enthalpy.

The expression for the change in internal energy.

The expression for the change in the entropy

Expert Solution & Answer

Want to see the full answer?

Check out a sample textbook solution

See solution

Chapter 11.9, Problem 47P

Chapter 11.9, Problem 49P

Students have asked these similar questions

2 A metal block of mass m = 10 kg is sliding along a frictionless surface with an initial speed Vo, as indicated below. The block then slides above an electromagnetic brake that applies a force FEB to the block, opposing its motion. The magnitude of the electromagnetic force varies quadratically with the distance moved along the brake (x): 10 FEB = kx², with k = 5 N m² V₁ = 8 m/s m = 10 kg FEB Frictionless surface Electromagnetic brake ⇒x Determine how far the block slides along the electromagnetic brake before stopping, in m.

Q1: Determine the length, angle of contact, and width of a 9.75 mm thick leather belt required to transmit 15 kW from a motor running at 900 r.p.m. The diameter of the driving pulley of the motor is 300 mm. The driven pulley runs at 300 r.p.m. and the distance between the centers of two pulleys is 3 meters. The density of the leather is 1000 kg/m³. The maximum allowable stress in the leather is 2.5 MPa. The coefficient of friction between the leather and pulley is 0.3. Assume open belt drive.

5. A 15 kW and 1200 r.p.m. motor drives a compressor at 300 r.p.m. through a pair of spur gears having 20° stub teeth. The centre to centre distance between the shafts is 400 mm. The motor pinion is made of forged steel having an allowable static stress as 210 MPa, while the gear is made of cast steel having allowable static stress as 140 MPa. Assuming that the drive operates 8 to 10 hours per day under light shock conditions, find from the standpoint of strength, 1. Module; 2. Face width and 3. Number of teeth and pitch circle diameter of each gear. Check the gears thus designed from the consideration of wear. The surface endurance limit may be taken as 700 MPa. [Ans. m = 6 mm; b= 60 mm; Tp=24; T=96; Dp = 144mm; DG = 576 mm]

Chapter 11 Solutions

Fundamentals of Engineering Thermodynamics

Ch. 11.9 - Prob. 1E Ch. 11.9 - Prob. 2E Ch. 11.9 - 3. What is an advantage of using the Redlich–Kwong...Ch. 11.9 - To determine the specific volume of superheated...Ch. 11.9 - Prob. 5E Ch. 11.9 - Prob. 6E Ch. 11.9 - Prob. 7E Ch. 11.9 - Prob. 8E Ch. 11.9 - Prob. 9E Ch. 11.9 - Prob. 10E

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.

The expression for the change in specific enthalpy. The expression for the change in internal energy. The expression for the change in the entropy