Using polynomial functions to characterize the bo surface

Kt follows a roughly log-linear pattern. Accordingly it is natural to choose the descriptive polynomials to be functions of In/fr rather than simply Kt-It is found that for a given value of speciflc-heat ratio, Y, the relationship between pidp and Kt may be modelled adequately by a fourth-order polynomial in In Tr  

Here bo( r 0.95) may be calculated for a given value of Y from a a fourth-order polynomial in InATr  

Hgure A2.2 Plot of long-pipe approximation parameter, bo, against frictional pressure loss in veiocity heads, Kt. and pressure 

---