Open Access

ARTICLE

Numerical Evaluation of the Performance Enhancement of S-Shaped Diffuser at the Intake of Gas Turbine by Energy Promoters

Hussain H. Al-Kayiem^1,*, Raed A. Jessam², Sinan S. Hamdi³, Ali M. Tukkee^4,5

1 Technical Engineering College, University of Hilla, Al-Hillah, Babylon, 51001, Iraq
2 Electromechanical Engineering Department, University of Technology-Iraq, Baghdad, 53050, Iraq
3 Nanotechnology and Advanced Materials Research Centre, University of Technology-Iraq, Baghdad, 53050, Iraq
4 Department of Petroleum Engineering, University of Kerbala, Karbala, 56001, Iraq
5 Air Conditioning and Refrigeration Techniques Engineering Department, University of Warith Al-Anbiyaa, Karbala, 56001, Iraq

* Corresponding Author: Hussain H. Al-Kayiem. Email:

(This article belongs to the Special Issue: Advancements in Energy Resources, Processes, Systems, and Materials-(ICSSD2024))

Energy Engineering 2025, 122(4), 1311-1335. https://doi.org/10.32604/ee.2025.061709

Received 01 December 2024; Accepted 27 January 2025; Issue published 31 March 2025

Abstract

Size reduction of the gas turbines (GT) by reducing the inlet S-shaped diffuser length increases the power-to-weight ratio. It improves the techno-economic features of the GT by lesser fuel consumption. However, this Length reduction of a bare S-shaped diffuser to an aggressive S-shaped diffuser would risk flow separation and performance reduction of the diffuser and the air intake of the GT. The objective of this research is to propose and assess fitted energy promoters (EPs) to enhance the S-shaped diffuser performance by controlling and modifying the flow in the high bending zone of the diffuser. After experimental assessment, the work has been extended to cover more cases by numerical investigations on bare, bare aggressive, and aggressive with energy promoters S-shaped diffusers. Three types of EPs, namely co-rotating low-profile, co-rotating streamline sheet, and trapezoidal submerged EPs were tested with various combinations over a range of Reynolds numbers from 40,000 to 75,000. The respective S-shaped diffusers were simulated by computational fluid dynamics (CFD) using ANSYS software adopting a steady, 3D, standard k-ε turbulence model to acquire the details of the flow structure, which cannot be visualized in the experiment. The diffuser performance has been evaluated by the performance indicators of static pressure recovery coefficient, total pressure loss coefficient, and distortion coefficient (DC(45°)). The enhancements in the static pressure recovery of the S-shaped aggressive diffuser with energy promoters are 19.5%, 22.2%, and 24.5% with EPs at planes 3, 4 and 5, respectively, compared to the aggressive bare diffuser. In addition, the installation of the EPs resulted in a DC(45°) reduction at the outlet plane of the diffuser of about 43% at Re = 40,000. The enhancements in the performance parameters confirm that aggravating the internal flow eliminates the flow separation and enhances the GT intake efficiency.

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