Entropy and the second law fluid flow and heat transfer simulation

U= internal energy density, J/m3 v= uid velocity vector, m/s x, y= Cartesian coordinates, m= ratio of specifi c heats 1= increment or change of quantity ¹= dynamic viscosity, kg/m¢ s ½= mass density, kg/m3¿= viscous stress, N/m2 8= viscous dissipation function, 1/s2