Heat Transfer Enhancement in Air Cooled Gas Turbine Blade Using

Abstract

In this paper, an investigation of using corrugated passages instead of circular crosssection passages was achieved in conditions simulate the case in the gas turbine blade coolingusing ANSYS Fluent version (14.5) with Boundary conditions: inlet coolant air temperature of300 K with different air flow Reynolds numbers (191000, 286000 and 382000). Thesurrounding constant hot air temperatures was (1700 K). The numerical simulations was done bysolving the governing equations (Continuity, Reynolds Averaging Navier-stokes and Energyequation) using (k-ε) model in three dimensions by using the FLUENT version (14.5). Thepresent case was simulated by using corrugated passage of 3 m long, internal diameter of 0.3 m,0.01 m groove height and wall thickness of 0.01 m, was compared with circular cross sectionpipe for the same length, diameter and thickness. The temperature, velocity distributioncontours, cooling air temperature distribution, the inner wall surface temperature, and thermalperformance factor at the two passages centerline are presented in this paper. The coolant airtemperature at the corrugated passage centerline was higher than that for circular one by(12.3%), the temperature distribution for the inner wall surface for the corrugated passage islower than circular one by (4.88 %). The coolant air flow velocity seems to be accelerated anddecelerated through the corrugated passage, so it was shown that the thermal performance factoralong the corrugated passage is larger than 1, this is due to the fact that the corrugated wallscreate turbulent conditions and increasing thermal surface area, and thus increasing heat transfercoefficient than the circular case.

Thermo-Hydraulic Analysis of Mixed Convection in a Channel-Square Enclosure Assembly with Hemi-Sphere Source at the Bottom

“…For the same reason that a higher input air velocity results in a more uniform velocity distribution, a higher absolute y-direction results in a more concentrated flow pattern towards the bottom of the enclosure. This verified very well with study [48]. The distribution of pressure in the enclosure along the negative y-axis for a range of intake velocities and a fixed 20 W heat source power is elucidated in Figure 7.…”

“…If one raises the speed of the air that enters the system, the airflow is going to be more turbulent, leading to a more even distribution of pressure. This verified very well with studies [44,45]. At different intake velocities and a fixed 20 W heat source power, the distribution of temperature alongside the positive y-axis in the assembly of channel-enclosure is revealed in Figure 10.…”

Mixed Convection Heat Transfer in a Channel-Open Cavity with Two Heat Sources

“…As y is increased in absolute value, the maximum Nusselt number decreases. This was thoroughly validated using [44]. Local velocity distribution in the channel-cavity assembly is shown in Figure 15 with two constant heat source powers of 20 W each and varied input air velocities ranging from 0.1 to 1.5 m/s.…”

Evaluation of Gas Turbine Performance in Power Plant with High-Pressure Fogging System

“…The possibility of erosion and corrosion when water is sprayed with air in the inlet of the gas turbine is a limiting factor, even if it is very small [15]. Since the compressor is an essential component of the gas turbine, it directly affects the production of the plant, therefore the technology of cooling air entering the compressor can be used [16][17][18][19][20][21][22][23]. Barakat et al [24] they tested a hybrid cooling system that included an underground heat exchanger.…”