Answer:
Assumption:
1. The kinetic and potential energy changes are negligible
2. The cylinder is well insulated and thus heat transfer is negligible.
3. The thermal energy stored in the cylinder itself is negligible.
4. The process is stated to be reversible
Analysis:
a. This is reversible adiabatic(i.e isentropic) process and thus
From the refrigerant table A11-A13
sat vapor
m=
b.) We take the content of the cylinder as the sysytem.
This is a closed system since no mass leaves or enters.
Hence, the energy balance for adiabatic closed system can be expressed as:
ΔE
ΔU
)
workdone during the isentropic process
=5.8491(246.82-219.9)
=5.8491(26.91)
=157.3993
=157.4kJ
Answer:
Explanation:
The VC-T engine (for "variable compression, turbocharged") can adjust its compression ratio between 8:1 and 14:1 on the fly, offering high-compression efficiency under light loads and the low compression needed for turbocharged power under hard acceleration.
Answer:
a) , b)
Explanation:
a) The coefficient of performance of a reversible refrigeration cycle is:
Temperatures must be written on absolute scales (Kelvin for SI units, Rankine for Imperial units)
b) The respective coefficient of performance is determined:
But:
The temperature at hot reservoir is found with some algebraic help:
Answer:
t = 2244.3 sec
Explanation:
calculate the thermal diffusivity
Temperature at 28 mm distance after t time = = 50 degree C
we know that
from gaussian error function table , similarity variable w calculated as
erf w = 0.909
it is lie between erf w = 0.9008 and erf w = 0.11246 so by interpolation we have
w = 0.08073
solving fot t we get
t = 2244.3 sec