Page 175 - 48Fundamentals of Compressible Fluid Mechanics

Adiabatic flow with friction name after Ginno Fanno a Jewish engineer is the sec-
ond model described here. The main restriction for this model is that heat transfer
1
is negligible and can be ignored . This model is applicable to flow processes which
are very fast compared to heat transfer mechanisms, small Eckert number. which are considerably
slower (see more discussion
about dimensionless
This model explains many industrial flow processes which includes empty- number in the chapter about
dimensional analysis (not
ing of pressured container through relatively a short tube, exhaust system internal included yet.).
combustion engine, compressed air systems, etc. As this model raised from need
to explain the steam flow in turbines.

9.1 Introduction

Consider a gas flows through a con- $&%
duit with a friction (see Figure 9.1). flow
It is advantages to examine the sim-
plest situation and yet without losing direction !
the core properties of the process.
#"
Later, more general case will be ex- c.v.
2
amined . '&(
No heat transer
Fig. 9.1: Control volume of the gas flow in a con-
1 Even the friction does not converted into heat stant cross section
2 Not ready yet, discussed on the ideal gas model and on the ideal gas model and the entry length
issues.

137