Flow control in s-shaped air intake diffuser of gas turbine using proposed energy promoters

Abstract

Abstract. This paper presents an experimental and numerical investigation of the flow control in an air intake S-shaped diffuser with and without energy promoters. The S-shaped diffuser had an area ratio 3.1and turning angle of 45°/45°. The proposed energy promoter was named as stream line sheet energy promoter. Computational Fluid Dynamics simulation was performed through commercial ANSYS-FLUENT 16.2 software. The measurements were made inside annular subsection, 45° from 360 o of the complete annular shape of the diffuser, at Reynolds number 5.8×10 4 and turbulence intensity 4.1%. Results for the bare S-shaped diffuser (without energy promoters) showed the flow structures within the S-shaped diffuser were dominated by counter-rotating vortices and boundary layer separation especially in the outer surface. The combination of the adverse pressure gradient at the first bend of outer surface and upstream low momentum wakes caused the boundary layer to separate early. The combinations of proposed energy promoters were installed on the inner and outer surfaces at three installation planes. The use of energy promoters resulting in significantly decreased the outer surface boundary layer separation with consequential improving the static pressure coefficient and reduction of total pressure losses.

Performance Enhancement of Solar Air Heater by Integrating Innovative Absorber Design and Automatic Control Flow Rate

“…The difference is clear because the air is almost static and does not flow over the static surface and depends only on the force of the buoyancy. But it is noticed, in the middle of the day during the period (11)(12)(13)(14) hours, that the CFS curve rises above the automatic VFS curve, as the fan speed increases automatically due to elevate temperature rates during this period until it reaches its peak value at 12:30, and thus the flow rate increases, while the flow rate remains constant in the CFS mode, despite the temperature rises in this mode to higher levels than the VFS mode. Figure 10 shows the variation in thermal efficiency of the SAH during the day under the two operation modes.…”

“…Figure 11 shows the sun's irradiance and the corresponding automatic variations in fan speed throughout the day. From sunrise until midday, both radiation and fan speed gradually rise according to changing SAH temperatures until they peak at (12)(13)(14)(15) o'clock and then both fall until sunset, resulting in efficient automatic fan speed adjustments in response to temperature and solar radiation levels.…”

“…Reducing the geometrical characteristics of various roughness, the higher-pressure drop may be increased. The ribs or energy promoters which fixed on the surfaces has a wide application to increase pressure coefficient of air flow by reducing its velocity [10][11][12] . Kulkarni and Kim 13) quantitatively studied four different barrier shapes and three unique combinations in SAHs.…”

Performance Enhancement of a Single Pass Solar Air Heater by Adopting Wire Mesh Absorber Layer

“…By reducing the geometrical characteristics of various roughness, the higher-pressure drop may be increased. The ribs or energy promoters which fixed on the surfaces has a wide application to increase pressure coefficient of air flow by reducing its velocity [17][18][19] . By experimenting with several rib placement structures on the surface, like inline, symmetric, and staggered layouts, the authors also looked at the morphologies of the ribs [20][21][22][23][24] .…”

Flow Performance Comparison Along the Centerline in Straight and S-Shaped Diffuser

“…The SVG pair was attached to each edge. A Jasmine et al [10] an experimental and numerical investigation of flow management was examined in comparison to energy promoters and in an air intake S-shaped diffuser compared to energy. Turning angle 45/45 is used with Maintenance Area ratio 3.…”