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ENGR5003 / Week 2
Lecture 6 worked example 1 - charging an insulated vesselTutorialCurrent specThird6 min

ENGR5003 Lecture 6 worked example 1 (slides 10-12)

An insulated vessel of negligible heat capacity contains 1 kg of air at 360 K. A compressor pumps in 2 kg of air at a temperature of 320 K. Find the final temperature of the air in the vessel. Assume γ=1.4\gamma = 1.4 for air.

Formulas you may need
  • Unsteady flow energy equation: ΔU=(h+12C2+gz)inΔmin−(h+12C2+gz)outΔmout+ΔQ−ΔW\Delta U = \left(h + \tfrac{1}{2}C^2 + gz\right)_{in}\Delta m_{in} - \left(h + \tfrac{1}{2}C^2 + gz\right)_{out}\Delta m_{out} + \Delta Q - \Delta W (on the formula sheet)
  • Ideal gas: u=cvTu = c_vT, h=cpTh = c_pT, γ=cp/cv\gamma = c_p/c_v (on the formula sheet)