The dimensionless thrust generated by supersonic flow through a convergent-divergent nozzle is given by Ref. 1,

1

which takes its optimum value, bmax when pe = pa.

For ideal one-dimensional flow, the relationship between Ae and pe is given by

2

and the optimum dimensionless thrust by

3

Where4

From equations (2) and (3), the constant D in equation (1) can be evaluated and thence the thrust of an ideal nozzle at any pressure ratio provided that no separation occurs.

Equations (2) and (3) are tedious to evaluate and it is not easy to estimate the effect of changes in γ.