What is the primary function of the diffuser in a gas turbine engine?

What is the primary function of the diffuser in a gas turbine engine?

• A. Divergent duct that increases pressure to prevent reverse flow of combustion gases back into the compressor
• B. Directly burn fuel
• C. Direct the air to the turbine
• D. Cool the exhaust

Answer: (A)

In a gas turbine, the diffuser’s job is to slow the high-velocity air leaving the compressor and convert its kinetic energy into static pressure, raising the air pressure before it enters the combustor. This divergent duct design increases pressure and helps keep the flow stable, reducing the risk of flow reversal or surge that could push gases back toward the compressor. That’s why the best description is a divergent duct that increases pressure to prevent reverse flow of combustion gases back into the compressor. The other ideas don’t fit: burning fuel happens in the combustor, not the diffuser; directing air to the turbine occurs after combustion, not through the diffuser; and cooling the exhaust is not a diffuser function.

In a gas turbine, the diffuser’s job is to slow the high-velocity air leaving the compressor and convert its kinetic energy into static pressure, raising the air pressure before it enters the combustor. This divergent duct design increases pressure and helps keep the flow stable, reducing the risk of flow reversal or surge that could push gases back toward the compressor. That’s why the best description is a divergent duct that increases pressure to prevent reverse flow of combustion gases back into the compressor. The other ideas don’t fit: burning fuel happens in the combustor, not the diffuser; directing air to the turbine occurs after combustion, not through the diffuser; and cooling the exhaust is not a diffuser function.