Detailed Simulations of a Three-Stage Supercritical Carbon Dioxide Axial Compressor with a Focus on the Shrouded Stator Cavities Flow

Journal Article · Fri Apr 28 00:00:00 EDT 2023 · Processes

DOI:https://doi.org/10.3390/pr11051358· OSTI ID:2418728

Ghimire, Saugat ^[1]; Turner, Mark ^[2]

---

1. Univ. of Cincinnati, OH (United States); University of Cincinnati, OH (United States)
2. Univ. of Cincinnati, OH (United States)

This paper describes the findings of detailed simulations performed to investigate the impact of seal teeth cavity leakage flow on the aerodynamic and thermal performance of a three-stage supercritical CO₂ axial compressor. The study compares a shrouded stator configuration (with cavities) to a cantilevered stator configuration (without cavities) to highlight their differences. High-fidelity computational fluid dynamics simulations were performed using non-linear harmonic (NLH) and mixing plane assumptions, considering various possible rotor/stator interface configurations for mixing plane calculations. The key performance parameters for each case were compared, and the best-performing configuration selected for further analysis. The individual stage performance parameters are also examined and compared between the cantilevered and shrouded configurations. It was observed that in the shrouded case, the leakage flow enters the cavity downstream of the stator trailing edge and gets entrained into the primary flow upstream of the stator, leading to boundary layer changes at the hub and degradation of stator and downstream rotor performance. Vortical flow structures were also observed in the stator wells, which tended to change the flow angles around the region, thereby affecting mixing and velocity distribution, resulting in a slight deterioration of compressor performance. Additionally, the study examines windage heating due to shear work from rotating walls, including the seal teeth surface. The amount of shear work done on the leakage flow and the corresponding rise in fluid temperature were quantified, tabulated, and further compared with a simple analytical model, showing good agreement between them and, hence, validating the numerical approach used.

• Research Organization: Echogen Power Systems (Delaware), Inc., Akron, OH (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
• Grant/Contract Number: EE0008997
• OSTI ID: 2418728
• Journal Information: Processes, Journal Name: Processes Journal Issue: 5 Vol. 11; ISSN 2227-9717
• Publisher: MDPI
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
Engineering
axial compressor
cavity
cavity leakage flow
hub cavity flow
seal teeth
shrouded stator
supercritical CO2