Study of Gas-Centered Coaxial Injector Using Jet …
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2.2 Experimental Setup
Cold flow atomization study of gas-centered coaxial injectors are planned using water
and GN2 as the simulating fluids. The experimental setup consists of a water feed
system; GN2 feed upstream/downstream of the pressure regulator. A filter system and
Instrumentation system. A water tank is used which can be pressurized using gaseous
nitrogen from a 50 L GN2 cylinder through a spring-loaded pressure regulator capable
of regulating from 140 bar to 30 bar. Pressure gauges are mounted on the water
tank as well as installed in the water line to avoid any particulates getting into
the injector. A needle valve is installed in the water line to regulate the flow. For
finding the pressure of water injection, there are two measurements are incorporated
(one pressure gauge and a strain gauge type pressure transducer). Setup bank of four
cylinders connected to a common header to supply the gaseous nitrogen. The pressure
is regulated by an inline pressure regulator with pressure measurement provisions
upstream and downstream. A needle valve installed in the gas line for controlling
the flow rate. Instrumentation system consists of measurement systems and data
acquisition systems. Measurement system is required for measuring and monitoring
parameters like pressure and flow. Data acquisition system acquires and records the
test parameters during the test which is used for analysis. Though many non-intrusive
procedure have been applied for measuring drop size patterns, Malvern Particle
Analyzer is most widely used. It is used to measure the SMD, process and record the
drop size data. It works based on Fraunhofer diffraction theory of a collimated laser
beam scattered by moving droplets.
3 Test Conditions
Experiments were carried out for injector element by varying Momentum Flux Ratio
of Liquid to Gas at different downstream positions. Momentum flux ratio of liquid
to gas is varied from 0.5 to 11 keeping into design considerations. In all case of
momentum flux ratio, mass flow rate of water was kept constant and GN2 mass
flow rate was varied. The GN2 mass flow rate was regulated through a needle valve
positioned in the GN2 feed line. Injectors hardware tested at different momentum flux
ratio at a particular position to find the spray and atomization characteristics. Malvern
Particle Analyzer was used to study the atomization characteristics. Experiments
at each MFR were repeated at different downstream positions. The downstream
positions were fixed by changing the distance from the injector exit to the Malvern
Particle Analyzer (Fig. 2).
371
2.2 Experimental Setup
Cold flow atomization study of gas-centered coaxial injectors are planned using water
and GN2 as the simulating fluids. The experimental setup consists of a water feed
system; GN2 feed upstream/downstream of the pressure regulator. A filter system and
Instrumentation system. A water tank is used which can be pressurized using gaseous
nitrogen from a 50 L GN2 cylinder through a spring-loaded pressure regulator capable
of regulating from 140 bar to 30 bar. Pressure gauges are mounted on the water
tank as well as installed in the water line to avoid any particulates getting into
the injector. A needle valve is installed in the water line to regulate the flow. For
finding the pressure of water injection, there are two measurements are incorporated
(one pressure gauge and a strain gauge type pressure transducer). Setup bank of four
cylinders connected to a common header to supply the gaseous nitrogen. The pressure
is regulated by an inline pressure regulator with pressure measurement provisions
upstream and downstream. A needle valve installed in the gas line for controlling
the flow rate. Instrumentation system consists of measurement systems and data
acquisition systems. Measurement system is required for measuring and monitoring
parameters like pressure and flow. Data acquisition system acquires and records the
test parameters during the test which is used for analysis. Though many non-intrusive
procedure have been applied for measuring drop size patterns, Malvern Particle
Analyzer is most widely used. It is used to measure the SMD, process and record the
drop size data. It works based on Fraunhofer diffraction theory of a collimated laser
beam scattered by moving droplets.
3 Test Conditions
Experiments were carried out for injector element by varying Momentum Flux Ratio
of Liquid to Gas at different downstream positions. Momentum flux ratio of liquid
to gas is varied from 0.5 to 11 keeping into design considerations. In all case of
momentum flux ratio, mass flow rate of water was kept constant and GN2 mass
flow rate was varied. The GN2 mass flow rate was regulated through a needle valve
positioned in the GN2 feed line. Injectors hardware tested at different momentum flux
ratio at a particular position to find the spray and atomization characteristics. Malvern
Particle Analyzer was used to study the atomization characteristics. Experiments
at each MFR were repeated at different downstream positions. The downstream
positions were fixed by changing the distance from the injector exit to the Malvern
Particle Analyzer (Fig. 2).