GAS DYNAMICS

While problems can be solved by use of the Mach function relationships which follow, it is expeditious to use Mach function tables and the problem solutions which are presented utilize the tables. For reference see "The Dynamics and Thermodynamics of Compressible Flow" by A. H. Shapiro.

Fundamental Relations:

Isentropic Relations for Perfect Gas:

At M = 1 (and k = 1.4):

Mass rate of flow per unit area:

For air:

where is in lbm/sec, A ^* is ft ², p _o in lbf/ft ² and T _o in R.

Isentropic Flow through a Nozzle:

Frictional Flow Relations (Constant Area, Adiabatic Flow):

Simple Heating - Rayleigh Line:

COMBUSTION

Fundamental Concepts:

• Air-Fuel Ratio (A/F) -

  • Mass or molal ratio of air to fuel in a combustion process.

• Stoichiometric -

  • A/F such that sufficient oxygen is present to fully oxidize the fuel with no excess oxygen.

• Heating Value (HV) or Heat of Reaction -

  • The amount of energy released by the chemical reaction being carried out either at constant pressure and temperature or constant volume and temperature.

• Higher Heating Value (HHV) -

  • The water formed by combustion is assumed condensed.

• Lower Heating Value (LHV) -

  • The water formed by combustion is assumed to remain in vapor phase.

Combustion Example Problems:

Problems in stoichiometry are divided into two main categories, depending on whether the...