# Symbols¶

Some sections of this documentation contain equations implemented by pandapipes. The meaning of the symbols used in these equations is explained here.

 Symbol Meaning $$\dot{m}$$ Mass flow $$c_p$$ Heat capacity at constant pressure $$T$$ Temperature $$p$$ Pressure $$\rho$$ Density $$g$$ Gravitational constant $$\Delta h$$ Height difference $$\lambda$$ Darcy friction factor $$l$$ Length $$v$$ Flow velocity $$d$$ Pipe diameter $$\zeta$$ Pressure loss coefficient $$K$$ Compressibility factor $$Re$$ Reynolds number $$k$$ Pipe roughness $$Q$$ Heat flow $$\alpha$$ Heat transfer coefficient