MOnday $\frac{3}{12}\frac{?}{2023}$

Prof Dr Elias Yfantis

$70\%$

Thermodynamics I

Air $($ideal gas, $m=1\mathrm{.}2kg,R=287\frac{J}{k}gK,k=1\mathrm{.}4)$ is the working fluid in the following thermodynamic processes:

$1-2$ : Adiabatic compression $($isentropic efficiency $0\mathrm{.}87).$

$2-3$: Constant volume heating.

$P_1=1-4$: Constant pressure heating.

$P1=1$ bar, $T1=27C,P_2=\frac{12}{b}ar,P3=\frac{18}{b}ar,u_4=2u_3(u=$ specific internal energy$).$

Calculate:

$W($total$).$

$Q($total$).$

$U($total$).$

$H($total$).$

Create the P$-$V$,$ V$-$T$,$ P$-$T diagrams.

A straight line on the $P-V$ diagram represents the $4-1$ process.

Calculate the thermal efficiency of the thermodynamic cycle $1-2-3-4-1.$