Fundamento
Conservation of mass
For one inlet and one outlet with no accumulation, the flow rates are equal.
\(\dot m_{in}=\dot m_{out}\)
ThermoLab · Chapter 5
Control volumes and the first law
Solves steady-flow equipment using enthalpy, velocity, elevation, heat and work.
Motor listo
Engineering results
NOT RUNDetailed calculation reportEquations · substitution · verification
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Engineering directory
13 linked modules on a single calculation base
Open any tool without losing your chosen unit system. Each page works on its own and keeps its navigation, report and export.
01
Appendices A-1 to A-28Universal property interpolator
→02Chapters 1 and 2Pressure, temperature and general energy balance
→03Chapter 3Pure substances and equations of state
→04Chapter 4Energy integrals for closed systems
→05Chapter 5Control volumes and the first law
→06Chapters 6 and 7Second law, Carnot and entropy
→07Chapter 8Exergy, destruction and second-law efficiency
→08Chapter 9Gas power cycles
→09Chapter 10Rankine steam power cycles
→10Chapter 11Refrigeration cycles
→11Chapters 12 and 13Gas mixtures and psychrometrics
→12Chapters 14 and 15Combustion and adiabatic flame temperature
→13Chapters 16 and 17Chemical equilibrium and compressible flow
→Engineering framework
Theory, equations and conditions of use
At steady state the stored energy does not change. The balance relates heat and work to enthalpy, kinetic energy and potential energy.
Fundamento
Flow energy
Enthalpy combines internal energy and flow work.
\(q-w=\Delta h+\Delta ke+\Delta pe\)
Fundamento
Shaft power
With the positive sign taken outwards, a turbine produces work and a compressor consumes it.
\(\dot W=\dot Q-\dot m[(h_2-h_1)+(V_2^2-V_1^2)/2+g(z_2-z_1)]\)
Base documentalÇengel & Boles, 7th edition · SI appendices A-1 to A-28
USCS conversionA-1E to A-27E, via exact factors from the SI base
AlcancePreliminary design, teaching and independent verification
Engineering FAQ
Preguntas frecuentes
When can I neglect kinetic energy?+
When the change in V²/2 is small compared with the enthalpy change.
Does a valve conserve enthalpy?+
In the adiabatic model, with no work and negligible kinetic and potential changes, h₁≈h₂.
What sign convention does work use?+
Positive when it leaves the control volume.