of starting characteristics, it is necessary to consider the influence of various factors
in the system design, and have corresponding special requirements for each component of EHPU. There are many difficulties involved. The theoretical modeling
and parameter matching of the system are difficult to some extent. In the process of
tackling this difficult problem, tackling key problems and phased experiments have
been experienced many times in order to finally meet the requirements of starting
characteristics.
9.5.2 EHPU Theoretical Modeling
EHPU gas generator, as a primary energy source, drives the turbine to rotate and
drives the generator and hydraulic pump to work. The gas flow through the nozzle
of the gas generator can be expressed as follows
G q ¼ C d F
ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi ffi
2g
k
k À 1
p b U b
p a
p b
2
k À
p a
p b
2
k þ 1
"
#
v
u
u
t
ð9:60Þ
where
G q Gas flow rate;
p b Import pressure;
C d Flow coefficient;
p a Export pressure;
F Flow area of gas generator nozzle;
U b Specific gravity of imported gas;
g Gravity acceleration;
k
Adiabatic index.
Fig. 9.54 Starting
characteristics of electronic
and hydraulic power unit (gas
pressure and power frequency
versus starting time)
152
9 High-Temperature and High-Speed Gas Turbine Pump …
in the system design, and have corresponding special requirements for each component of EHPU. There are many difficulties involved. The theoretical modeling
and parameter matching of the system are difficult to some extent. In the process of
tackling this difficult problem, tackling key problems and phased experiments have
been experienced many times in order to finally meet the requirements of starting
characteristics.
9.5.2 EHPU Theoretical Modeling
EHPU gas generator, as a primary energy source, drives the turbine to rotate and
drives the generator and hydraulic pump to work. The gas flow through the nozzle
of the gas generator can be expressed as follows
G q ¼ C d F
ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi ffi
2g
k
k À 1
p b U b
p a
p b
2
k À
p a
p b
2
k þ 1
"
#
v
u
u
t
ð9:60Þ
where
G q Gas flow rate;
p b Import pressure;
C d Flow coefficient;
p a Export pressure;
F Flow area of gas generator nozzle;
U b Specific gravity of imported gas;
g Gravity acceleration;
k
Adiabatic index.
Fig. 9.54 Starting
characteristics of electronic
and hydraulic power unit (gas
pressure and power frequency
versus starting time)
152
9 High-Temperature and High-Speed Gas Turbine Pump …