Energy transfer in mechanical systems: During steady-state operation, a mechanical gearbox receives 70 KW of input power through
the input shaft and delivers power through the output shaft. Considering the gearbox as a thermodynamic system, the rate of convection heat transfer generated during its operation is defined by: where h 0.171 kW/m2-K is the convection heat transfer coefficient, A 1.0 m is the outer surface area of the gearbox, T 300 K is the temperature of the outer surface, and T 293 K is the temperature of the surrounding air. For the gearbox, evaluate the heat transfer rate, 2, and the power delivered through the output shaft, W.
1 answer:
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Answer:
V1=5<u>ft3</u>
<u>V2=2ft3</u>
n=1.377
Explanation:
PART A:
the volume of each state is obtained by multiplying the mass by the specific volume in each state
V=volume
v=especific volume
m=mass
V=mv
state 1
V1=m.v1
V1=4lb*1.25ft3/lb=5<u>ft3</u>
state 2
V2=m.v2
V2=4lb*0.5ft3/lb= <u> 2ft3</u>
PART B:
since the PV ^ n is constant we can equal the equations of state 1 and state 2
P1V1^n=P2V2^n
P1/P2=(V2/V1)^n
ln(P1/P2)=n . ln (V2/V1)
n=ln(P1/P2)/ ln (V2/V1)
n=ln(15/53)/ ln (2/5)
n=1.377
