Solution cont. a single stream of air T1=21C P=5 bars Inlet Now the 2nd law: T32=79C P2=I bar Hot outlet 0 0= T +rins1-rins2-rigs3 +ev Cold outlet T3=-18C P3=I bar 60%mass (no significant heat transfer, m3= 0.6i1m2=0.4m1 insulated) 0=(m2+m3)S1-m2S2-m3S3+0cv Question:m3=10%m ? =m2(S1-S2）+m3(S1-S3)+v Ideal gas model = 0.4im1(s1-S2）+0.6m1(S1-S3）+cv L -Rn P =0.454 kJ/kg.K >0 satisfies 2nd law Does exist:vortex tube 上游充通大学 April 26,2018 12 SHANGHAI JIAO TONG UNIVERSITYApril 26, 2018 12 Solution cont. a single stream of air 60% mass Now the 2nd law: (no significant heat transfer, insulated) Ideal gas model >0 satisfies 2nd law Does exist: vortex tube Question: m3=10% m1 ??