Multistage Compressor with 2 Rotor and 2 Stator rows, ANSYS Fluent Tutorial

Description

Description

This simulation is about a Multistage Compressor with 2 rotors and 2 stator rows via ANSYS Fluent software. We perform this CFD project and investigate it by CFD analysis.

The compressor designed in this simulation is of axial type and consists of four rows, including two rows of stator and two rows of the rotor. In general, axial flow compressors are compressors whose airflow is parallel to the axis of rotation.

Axial compressors consist of two main parts: the rotor and the stator. Rotors are rows connected to the central shaft and rotate around the central axis of the compressor at a very high speed. Stators, on the other hand, are fixed and without rotation rows.

The primary function of rotors is to apply torque to the airflow and accelerate the air through rotational motion. The primary function of stators is to increase the air pressure and prevent its spiral movement around the longitudinal axis by equalizing the current parallel to the longitudinal axis of the compressor.

In other words, the stators convert the increased kinetic energy inside the compressor into static pressure and change the direction of air movement so that the airflow is ready to enter the next rotor. This simulation distinguishes two areas called stators and two areas called rotors.

The present model is designed in two dimensions using Design Modeler software. The model includes two rows of the rotor and two rows of the stator. Each row of stator or rotor consists of 22 blades with an airfoil cross-section.

The rotor blades have deflection, but the stator blades are horizontal and without deflection. Due to the perfectly symmetrical structure of this geometry and to reduce the computational cost, only one blade of each row of stator and rotor has been designed, and the periodic boundary condition has been used for its lateral surfaces.

The model is then meshed by ANSYS Meshing software. The model mesh is unstructured, and 972354 cells have been created.

Multistage Compressor Method

In this simulation, the stator section is static, and all its walls are defined as stationary walls. However, the rotor section is defined as a moving zone using the Frame Motion method in cell zone conditions, and all the walls related to this section are also movable.

Therefore, a rotational motion with a rotational velocity of 25,000 rpm is defined for the airflow in the rotor area. Also, since the model’s prominent nature is related to pressure changes, the pressure boundary condition is used at the input and the output.

Multistage Compressor Conclusion

After simulation, two-dimensional and three-dimensional contours related to pressure, velocity, turbulence kinetic energy, and pressure gradient are obtained.

Also, the airflow pathlines inside the compressor are obtained in three dimensions. Also, pressure and wall tension contours have been obtained on the blades’ body, the rotor’s central part, and the stator’s rotor.

The results show that the airflow pressure increases in the direction of horizontal airflow movement parallel to the compressor’s central axis. Also, the pathlines show the rotational movement around the rotors and stators well.