A non-ideal gas work process: A Van der Waals gas has an equation of state given

Question

A non-ideal gas work process: A Van der Waals gas has an equation of state given by ( p + a/v2 )(v - b) = RT. where R is the gas constant and v is the specific volume. Calculate the work, 1W2 = 21 pdv for an ISOTHERMAL expansion process using oxygen as the working fluid. Use T= 500K, v1 = 1m3/kg and v2 = 2m3/kg. Also use a = 0.01kPam6/kg2 and b = 0.01m3/kg. For the R value calculation see # 3 on the formula sheet and note that W = 32 kg/kmole for oxygen. Draw the process on a p-v diagram. Expansion process in a piston cylinder: Air. assumed to behave as an ideal gas (pv = RT), undergoes adiabatic expansion in a piston cylinder from the initial condition T1 = 2000K, p1 = 4 MPa. undergoes

Explanation / Answer

p =(RT/(v-b)) -a/v^2

pdv =[(RT/(v-b)) -a/v^2]dv=[RT ln(v-b) +a/v]limt frm 1to 2 .......T,R,a,b are constants

=[RT ln(v2-b)/(v1-b) +a/v2-a/v1]

putting given values and for oxygen R =8.31 kJ/kmol.K = =265 j/kgK

we get W =92509.5 j

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.