Answer:
The entropy change of the air is 
Explanation:

is unknown
we can apply the following expression to find 


now substitute

To find entropy change of the air we can apply the ideal gas relationship
Δ

Δ

Δ
Answer:
18 kJ
Explanation:
Given:
Initial volume of air = 0.05 m³
Initial pressure = 60 kPa
Final volume = 0.2 m³
Final pressure = 180 kPa
Now,
the Work done by air will be calculated as:
Work Done = Average pressure × Change in volume
thus,
Average pressure =
= 120 kPa
and,
Change in volume = Final volume - Initial Volume = 0.2 - 0.05 = 0.15 m³
Therefore,
the work done = 120 × 0.15 = 18 kJ
Answer:
a) isentropic efficiency = 84.905%
b) rate of entropy generation = .341 kj/(kg.k)
Please kindly see explaination and attachment.
Explanation:
a) isentropic efficiency = 84.905%
b) rate of entropy generation = .341 kj/(kg.k)
The Isentropic efficiency of a turbine is a comparison of the actual power output with the Isentropic case.
Entropy can be defined as the thermodynamic quantity representing the unavailability of a system's thermal energy for conversion into mechanical work, often interpreted as the degree of disorder or randomness in the system.
Please refer to attachment for step by step solution of the question.
Answer:
155fts
Explanation:
We apply the bernoulli's equation to get the depth of water.
We have the following information
P1 = pressure at top water surface = 0
V1 = velocity at too water surface = 0
X1 = height of water surface = h
Hf = friction loss = 0
P2 = pressure at exit = 0
V2 = velocity at exit if penstock = 100ft/s
X2 = height of penstock = 0
g = acceleration due to gravity = 32.2ft/s²
Applying these values to the equation
0 + 0 + h = 0 + v2²/2g +0 + 0
= h = 100²/2x32.2
= 10000/64.4
= 155.28ft
= 155
Answer:
= -0.303 KW
Explanation:
This is the case of unsteady flow process because properties are changing with time.
From first law of thermodynamics for unsteady flow process

Given that tank is insulated so
and no mass is leaving so

Mass conservation 
is the initial and final mass in the system respectively.
Initially tank is evacuated so 
We know that for air
,

So now putting values

= -0.303 KW