CFD Simulation of the Intermediate Passage Of Gas Turbine With Energy Promoters

The bulky size of gas turbine has always become a great factor and limit in designing oil and gas offshore platforms. This paper presents simulations results on the effect of energy promoters in an aggressive intermediate gas turbine diffuser. A typical S-shaped diffuser is modeled and simulated to become in FLUENT 6.3.26 assuming 2-D and incompressible flow. The promoters were selected with triangular shape of 25o frontal edge. The effect of energy promoters was investigated with various configurations to obtain the best height, and position. The simulation was carried out with five different heights of 0.5, 1.0, 1.5, 2.0 and 2.5 mm and five different promoter locations in the upstream part of the diffuser. The exit static pressure recovery, which ultimately affects the diffuser’s efficiency, was adopted as an indication for the diffuser performance. The simulation results show that the energy promoters works as intended, but still far from reaching the benchmark efficiency of a normal/ideal diffuser. Among 5o, 10o, 15o, 20o and 25o of location angles in the inlet bend, the 10o location was found to be the most effective location. The promoters with 2.0 mm height display the highest exit pressure recovery. Further simulation will be required in three dimensional, as well as experimental investigations to explore furthermore on the promoters contribution in enhancing the diffusers efficiency.