what is it ill know your question??!!
Answer:
d) Is the thermal conductivity of the medium constant or variable.
Explanation:
As we know that
Heat equation with heat generation at unsteady state and with constant thermal conductivity given as
With out heat generation
In 2 -D with out heat generation with constant thermal conductivity
Given equation
So we can say that this is the case of with out heat generation ,unsteady state and with constant thermal conductivity.
So the option d is correct.
d) Is the thermal conductivity of the medium constant or variable.
Answer:
9.7g / cm^3
Explanation:
To calculate a conbined density we must find the ratio between the sum of the masses and the sum of the volumes remembering that the equation to find the density is α=m/v, taking into account the above the following equation is inferred.
αc=copper density
αs=silver density
Vs=volume of silver
Vc=volume of copper
α= density of alloy
the density of the alloy is 9.7g / cm^3
Answer:
the isentropic efficiency of turbine is 99.65%
Explanation:
Given that:
Mass flow rate of LNG m = 20 kg/s
The pressure at the inlet = 3000 kPa
turbine temperature at the inlet = ( -160+273)K = 113K
The pressure at the turbine exit = 300 kPa
Power produced by the turbine W = 120 kW
Density of LNG
The formula for the workdone by an ideal turbine can be expressed by:
We all know that density = mass * volume i.e
Then ;
replacing it into the above previous derived formula; we have:
However ; the isentropic efficiency of turbine is given by the relation:
99.65%
Therefore, the isentropic efficiency of turbine is 99.65%