T inspire notes
- 1. Tab 1 Concepts Energy can be transferred across a boundary of an open system by work, heat, and mass. Kelvin-Planck statement of 2nd law: It is impossible to construct a device which operates on a cycle and produces no other effect than the production of work and the transfer of heat from a single body. Clausius Statement: It is impossible to constructa device which operates on a cycle and whose sole effect is the transfer of heat from a cooler bodyto a hotter body. Refrierator coefficient of performance in terms of heat transfer: COP_r=(QL)/(QH-QL) Nozzles do not transfer work or heat and Compressors do nottransfer heat. Thermodynamic temperature: on formula sheet V=velocity; v=specific volume A=(pi*D^2)/4;; D=sqrt((4*A)/pi)) Tab 2 Review Mass flow rate: m(dot)=VA/v Mass Balance: m(dot)1=2=3 1st law open sys:q-w=delta(h)+delta(ke)+delta(pe) heat engines: Qh-Ql=Wout Heat pumps/refrigerator: Qh-Ql=Wa 2nd law statements: WeirdMhe=Wout/Qh=1/(QL/Qh) COPr=Ql/Win=QL/(Qh-QL) COPhp=Qh/Win=Qh/(Qh-Ql) Energy quality: WeirdMmax= Wmax/QL?
- 2. Carnot cycles(rev): WeirdMhemax=1-(TL/Th) COPrmax= TL/(Th-TL) COPhemax= TL/(Th-TL) Wmax=QnWeirdMmax= Qh(1-TL/Th) Tab 3 More Formulas Adiabatic air compressor:W(dot)in=m(dot)(h2-h1)=m(dot)cp(T2-T1) Specific Volume of Air: V1=(RT1)/P1 Adiabatic capillary tube: m(dot)h1=m(dot)h2 Quality exit: x2=(h2-h1)/hfg M(dot)=(1/v1)A1V1 (on formula sheet) Nozzle: h1+(V1^2/2)=h2+(V2^2/2) +Qout/m(dot) Conservation of Mass Relation:(1/V2)A2Va=(1/V1)A1V1;;; (A1/A2)=((T1/P1)/(T2/P2))V2/V1 Diffusor: Enthalpy is internal energy +flow work Weird M is efficiency. Can never be grater than one. A percentage V=RT/P;W(dot)flow =M(dot)PV A1V1/v1 = A2V2/v2