Steam Turbine

Introduction

This study investigates the flow dynamics within a steam turbine configuration using Computational Fluid Dynamics (CFD) analysis. The simulation aims to understand the complex flow behavior, pressure distributions, temperature variations, and velocity profiles within the turbine. By employing advanced models for turbulence and real gas behavior, this research provides valuable insights into the performance and efficiency of steam turbines.

The CFD simulations were conducted using ANSYS Fluent software. The geometry, which is designed in Spaceclaim, represents a 3-dimensional steam turbine configuration, with the mesh generated in ANSYS Meshing. The mesh consists of about 19 million tetrahedral elements, providing a high-quality representation of the complex turbine geometry.

Methodology

A density-based solver is employed for the solution and is suitable for compressible flow simulations. For turbulence modeling, the Realizable k-ε model with standard wall function is utilized, known for its robustness in predicting complex turbulent flows. The energy equation is enabled to solve for temperature distributions and heat transfer effects. The working fluid is air, with real-gas-peng-robinson model is employed for compressible flow, and a moving reference frame is activated for the rotating zone at 100 rpm to capture rotational effects. We employ an implicit formulation for numerical stability and efficient convergence.

Results

The simulation results demonstrate the intricate flow behavior within the steam turbine. The pressure and temperature distributions provide insights into the energy conversion process, while the velocity profiles reveal the flow acceleration through the blade passages. At the Inlet, the pressure is higher than in other regions, and it gradually decreases toward the outlet. In the temperature contour, you can see that the temperature is also highest near the Inlet. Between the blades, the temperature reaches its minimum, and in this region, the pressure is also low. For the velocity contour, you can see that in the same region where the pressure and temperature are lowest, the velocity is higher than in other areas. This behavior is consistent with the flow acceleration through the blade passages.