d 2 Combustion pressure deviation caused by relative deviation of grain
pressure index;
d 3 Combustion pressure deviation caused by relative deviation of grain
temperature sensitivity coefficient.
When the adjusted relative deviation of combustion pressure is substituted into
Eq. (9.37), k ¼ 7% is obtained, which meets the experience value d
½ ¼ 8%
which is usually allowed in design.
9.4 Design Principle of Small Gas Turbine for Missile
9.4.1 Thermodynamic Process in Small Gas Turbine Nozzle
for Missile
The missile uses the hot gas generated by retarded propellant combustion as the
power source, drives the gas turbine, drives the hydraulic pump and generator, and
provides the hydraulic energy and power for the whole missile. The process of
converting heat energy of gas into mechanical energy in gas turbine is completed in
one time in the nozzle. In this section, the thermodynamic process of gas passing
through the nozzle is analyzed, and the practical nozzle flow formula is deduced by
using the first law of thermodynamics.
Small gas turbines for missiles are generally single-stage pure impulse turbines.
The process of converting heat energy of gas into mechanical energy is completed
at one time in the nozzle. Therefore, the analysis of the thermodynamic process in
the nozzle is of great significance to the thermodynamic calculation of the turbine
and the study of its variable working condition characteristics.
The working process of working fluid in thermal power machinery can be
basically divided into the following situations:
(1) Constant pressure process;
(2) Constant volume process;
(3) Isothermal process;
(4) Isentropic adiabatic process;
(5) Variable process.
The nozzle is relatively short, and the friction loss in the nozzle can be generally
neglected. Considering the high speed of the airflow, the heat exchange between the
nozzle and the outside can also be neglected. The flow process of gas in the nozzle
can be regarded as isentropic and adiabatic process. This simplification is also
significant for studying the variable working condition characteristics of the nozzle
and making qualitative analysis.
9.3 Design Principle of Gas Generator
135
pressure index;
d 3 Combustion pressure deviation caused by relative deviation of grain
temperature sensitivity coefficient.
When the adjusted relative deviation of combustion pressure is substituted into
Eq. (9.37), k ¼ 7% is obtained, which meets the experience value d
½ ¼ 8%
which is usually allowed in design.
9.4 Design Principle of Small Gas Turbine for Missile
9.4.1 Thermodynamic Process in Small Gas Turbine Nozzle
for Missile
The missile uses the hot gas generated by retarded propellant combustion as the
power source, drives the gas turbine, drives the hydraulic pump and generator, and
provides the hydraulic energy and power for the whole missile. The process of
converting heat energy of gas into mechanical energy in gas turbine is completed in
one time in the nozzle. In this section, the thermodynamic process of gas passing
through the nozzle is analyzed, and the practical nozzle flow formula is deduced by
using the first law of thermodynamics.
Small gas turbines for missiles are generally single-stage pure impulse turbines.
The process of converting heat energy of gas into mechanical energy is completed
at one time in the nozzle. Therefore, the analysis of the thermodynamic process in
the nozzle is of great significance to the thermodynamic calculation of the turbine
and the study of its variable working condition characteristics.
The working process of working fluid in thermal power machinery can be
basically divided into the following situations:
(1) Constant pressure process;
(2) Constant volume process;
(3) Isothermal process;
(4) Isentropic adiabatic process;
(5) Variable process.
The nozzle is relatively short, and the friction loss in the nozzle can be generally
neglected. Considering the high speed of the airflow, the heat exchange between the
nozzle and the outside can also be neglected. The flow process of gas in the nozzle
can be regarded as isentropic and adiabatic process. This simplification is also
significant for studying the variable working condition characteristics of the nozzle
and making qualitative analysis.
9.3 Design Principle of Gas Generator
135