Approximations that further simplify the energy equation

Approximations that further simplify the energy equation 

All chemical species may be considered to have constant and equal average specific heats at constant pressure Cp. 

The effective coefficient of viscosity (f/z -h k) equals the ratio of the thermal conductivity to the average specific heat (A/c ). 

Assumption 7 is not essential because the important qualitative results to be obtained do not depend on this assumption. However, it enables the analysis to be simplified considerably and, in some respects, clarifies the physical significance of the results. In view of assumption 7, equation (1-11) reduces to 

Assumption 8 is entirely unnecessary for ordinary deflagrations (that is, for p constant) because the terms involving the viscosity are negligibly small. However, this assumption leads to a considerable simplification in the analysis for detonations and for flames with nonnegligible kinetic energy. Assumption 8 states that 

---