# 5-1 Principles of Gas Turbine Operation SQ

 Describe the relationship between pressure and velocity in a closed system. Together they make up total pressure. To keep total pressure the same, if pressure increases, velocity decreases. Vice versa How does subsonic airflow react through a convergent opening? A divergent opening? ConvergentPressure DecreasesVelocity Increases DivergentPressure IncreasesVelocity Decreases How does supersonic airflow react through a convergent opening? A divergent opening? ConvergentPressure IncreasesVelocity Decreases DivergentPressure DecreasesVelocity Increases What happens to the airflow as it passes through a nozzle? A diffuser? NozzleVelocity IncreasesPressure Decreases DiffuserVelocity DecreasesPressure Increases What are the three sections of a gas generator? CompressorBurnerTurbine How does a gas turbine engine produce thrust? By rapidly compressing, heating, and accelerating a large quantity (mass) of air and fuel. What cycle explains the movement of air through a gas generator? Brayton Cycle What happens to the velocity of the gases as they pass through the compressor section? The burner section? The turbines? Compressor - Remains fairly constantBurner - Velocity IncreasesTurbines - Velocity increases What is gross thrust? Thrust measured at exhaust at standard day conditions 29.92 and 15° C What is net thrust? Thrust measured under normal flight conditions. When are gross thrust and net thrust equal? When aircraft is in a static position (inlet airflow is zero) and at standard day conditions. What affects the density of the air mass? TemperaturePressureAltitude What happens to thrust when air density decreases? Thrust decreases What happens to thrust when air temperature increases? Thrust decreases What happens to thrust when air pressure decreases? Thrust decreases What is the relationship between pressure and temperature as altitude increases? Pressure decreasesTemperature decreases (until 36,000) feetThrust will decrease What is the optimum cruise altitude and why? Approximately 36,000 feetTemperature remains constant in the isothermal layer How does airspeed and the ram effect change the amount of thrust produced at subsonic and supersonic airspeeds? Airspeed increase without ram effect causes thrust to decreaseAirspeed increase with ram effect causes thrust to remain relatively constant at subsonic speeds and increased greatly at supersonic speeds. Authordundane ID320948 Card Set5-1 Principles of Gas Turbine Operation SQ DescriptionStudy Questions Updated2016-06-16T14:46:12Z Show Answers