Steady Numerical Investigation on the Flow and the Heat Transfer in a Gas Turbine Disk Cavity With Pre-Swirl Nozzles Under Axisymmetric Boundary Condition
Over the past decades, the amount of air used in a gas turbine disk cavity already reach up to 3.6% of the mass flow rate at the compressor inlet. Understanding the characteristics of the flow and the heat transfer in the disk cavity is of vital importance to reduce the air consumption and then further improve the efficiency. Although the pre-swirl nozzles are widely used in the disk cavities, investigation of the flow structure and the heat transfer are mainly about the rotor-stator disk cavity with central inflow. The investigations concerning the characteristics of the flow and the heat transfer in such a cavity are still not sufficient. The influence of the swirl flow on the flow and heat transfer characteristics in the disk cavity are still not clear, especially with high pre-swirl angle and large through flow coefficients.
In this work, the characteristics of the flow and the heat transfer in the disk cavity with pre-swirl nozzles are numerically studied. A commercial software ANSYS CFX 15.0 is adopted. The distributions of the flow at three branches are predicted under various rotational speeds and through-flow coefficients. The vortex structures are presented and analyzed at each working condition. The distributions of the core swirl ratio are presented and analyzed. The vortex structures are significantly affected by the mass flow rate through the pre-swirl nozzles while it is not the case for the rotational speed. The vortex structures indicate that the flow characteristics of the target rotor-stator disk cavity with pre-swirl nozzle is different from the classical model. Thus, the heat transfer cannot be predicted by the existing heat transfer correlation. The heat transfer coefficients are obtained and analyzed in the following part. The results indicate that the enhanced heat transfer region can be explained by the high-speed flow and the vortex. The obtained results can help the designers to better design the geometry of the disk cavity with pre-swirl nozzles in a gas turbine.
Steady Numerical Investigation on the Flow and the Heat Transfer in a Gas Turbine Disk Cavity With Pre-Swirl Nozzles Under Axisymmetric Boundary Condition
Category
Technical Paper Publication
Description
Session: 12-00 Heat Transfer: Internal Air Systems & Seals (Joint with Turbomachinery) On-Demand Session
ASME Paper Number: GT2020-15785
Start Time: ,
Presenting Author:
Authors: Yan Wang Tsinghua University
Bo Hu Tsinghua University
Xuesong Li Tsinghua University
Xiaodong Ren Tsinghua University
Chunwei GuTsinghua University