Analysis and Identification of the Flow Pattern in a Specific High-Pressure Axial Turbine in Off-Design Conditions

Saharkhiz, Sahar; Aghaei Togh, Reza

doi:10.22034/jtae.2024.8.3.4

Analysis and Identification of the Flow Pattern in a Specific High-Pressure Axial Turbine in Off-Design Conditions

Document Type : Research Article

Authors

Sahar Saharkhiz ¹

Reza Aghaei Togh ²

¹ M. Sc. Student, Department of Aerospace Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran

² Assistant Professor, Department of Aerospace Engineering, Faculty of Engineering, Islamic Azad University Science and Research Branch, Tehran, Iran

10.22034/jtae.2024.8.3.4

Abstract

This research aims to identify the flow pattern in off-design conditions of a specific high-pressure axial turbine. The turbine was designed by writing the preliminary design code. Then, the geometry of this turbine was designed in CATIA and Ansys Design Modeler software, and it is meshed in Turbogrid software. The turbine is analyzed using the Ansys CFX software at 12 points in off-design conditions. With a fixed rotor speed ratio, the inlet static pressure ratio was changed. Then, with a fixed inlet static pressure ratio, the rotor speed ratio was changed. With the increase of the inlet static pressure ratio, the Mach number of the flow reached above one, and the turbine efficiency dropped significantly. Reducing the inlet static pressure ratio to a certain extent improved the performance of the turbine. However, with a further drop in the inlet static pressure ratio, the turbine efficiency began to decline. The working conditions at the inlet static pressure ratio of 0.9 are better compared to other working points, and the turbine efficiency reaches 0.93. With changes in the rotor speed ratio, the areas prone to flow separation around the turbine blades increased, especially on the suction surface of the rotor blades.

Keywords

High-Pressure Axial Turbine

Off-Design Conditions

Rotor Speed Ratio

Inlet Static Pressure Ratio

Flow Separation

Turbine Efficiency

Subjects

Propulsion/Thermodynamics/Heat Transfer/Fuel and Combustion/Energy/...

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