In this study, this parameter was chosen equal to the
blade chord on the 5 sections in which the experiment took place.
As shown by Table 4, four configurations of computational domains (Figure 6) were evaluated including: the baseline configuration consisting of a half of blade rows of 23 vanes and 32 blades, the configuration "NGV 11:16" consisting of 11 vanes and 16 blades (vane chord reduced by 4.5%), the configuration "NGV 3: 4" consisting of 3 vanes and 4 blades (vane chord reduced by 4.2%), and the last configuration "rotor 2: 3" consisting of 2 vanes and 3 blades (
blade chord reduced by 7.25%).
Geometric parameters Turbine 1 Turbine 2 Length blade [m] 3.2 3.2
Blade chord [m] 0.35 0.18 Airfoil NACA 0021 NACA 0021 Solidity 0.5 0.5 Diameter 2.12 1.06 No.
Also
blade chord distribution changes, increasing from 825 mm at the root up to maximum chord of 1180 mm at z = 2030 mm and then decreasing gradually along the span, down to 50 mm at the tip.
To reduce blade weight--and hence the disc and containment ring--the
blade chord also had to below.
Wind
blade chord and twist angle optimization by using genetic algorithms, Institute of Intelligent Systems and Numerical Applications in Engineering, Univ.
in which [p.sub.s_Fan] is the static pressure of the fan, [??] is the average nondimensionalized pressure gradient on the fan blade, and L is the
blade chord length.
"It's very abrasive and the concern is that when encountered in the high-pressure compressor, it will wear the blades and vanes, and you can reduce the length of the
blade chord. You will impact the aerodynamic behaviour of the compressor, potentially leading to engine stall and, ultimately, loss of thrust." Particles entering an engine's combustion chamber would encounter very high temperatures, of up to 2,400 C (4,352 F), and melt before reaching the high-pressure turbine's nozzle - where temperatures are lower - causing them to deposit on the vanes.
The pressure measurements are made at three radial stations (r/R = 0.75, 0.87, and 0.97) of the reference blade (H1Y) for the complete pressure distribution along the
blade chord. A total of 32 strain gauges are attached on the blade surface, distributed between r/R = 0.14 and 0.83, to measure the structural loads as well as the elastic deformation of the blade.
In our previous study, it was confirmed that efficiency degradation may occur if the
blade chord Reynolds number decreases below [10.sup.5] [43].
